1. A measuring device, comprising: the device comprises a laser emitting unit, a laser processing unit, a power adjusting unit, an optical coupling unit and a data processing unit;

the laser emitting unit is used for generating a laser signal and inputting the laser signal into the laser processing unit;

the laser processing unit is used for converting the laser signal into a pulse light signal which appears periodically and inputting the pulse light signal into the power adjusting unit; the pulse light signals comprise a first pulse light signal and a second pulse light signal, the frequency bands of the first pulse light signal and the second pulse light signal are different, and the occurrence time of the first pulse light signal and the second pulse light signal is different;

the power adjusting unit is used for adjusting the power of the first pulse light signal to obtain a third pulse light signal and adjusting the power of the second pulse light signal to obtain a fourth pulse light signal;

the power adjusting unit is further used for inputting the third pulse optical signal and the fourth pulse optical signal into the optical coupling unit;

the optical coupling unit is used for inputting the third pulse optical signal and the fourth pulse optical signal into a sensing optical fiber and receiving first scattered light generated by the third pulse optical signal in the sensing optical fiber and second scattered light generated by the fourth pulse optical signal in the sensing optical fiber; inputting the first scattered light and the second scattered light into the data processing unit;

the data processing unit is used for obtaining the information of the sensing optical fiber according to the first scattered light and the second scattered light.

2. The measurement apparatus according to claim 1, wherein the power of the third pulsed light signal is less than a stimulated brillouin threshold and the power of the fourth pulsed light signal is greater than the stimulated brillouin threshold, or wherein the power of the third pulsed light signal and the power of the fourth pulsed light signal are both less than the stimulated brillouin threshold.

3. The measurement device according to claim 2, wherein the data processing unit comprises: a photoelectric detection unit, a data acquisition unit and a system control unit,

the photoelectric detection unit is used for receiving the first scattered light and the second scattered light, converting the first scattered light into a first electric signal, and converting the second scattered light into a second electric signal; inputting the first electric signal and the second electric signal into the data acquisition unit;

the data acquisition unit is used for receiving the first electric signal and the second electric signal, converting the first electric signal into a first digital signal, and converting the second electric signal into a second digital signal; and inputting the first digital signal and the second digital signal to the system control unit;

the system control unit is used for receiving the first digital signal and the second digital signal, demodulating the first digital signal to obtain vibration information of the sensing optical fiber, and demodulating the second digital signal to obtain temperature and deformation information of the sensing optical fiber.

4. The measuring device according to claim 3, the system control unit being connected to the laser processing unit and the power regulating unit,

the system control unit is further used for updating the frequency band and the pulse width of the first pulse optical signal and the power of the third pulse optical signal according to the obtained vibration information of the sensing optical fiber; updating the frequency band and the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal according to the obtained temperature and deformation information of the sensing optical fiber;

the system control unit is further used for sending a first control signal to the laser processing unit to indicate the updated frequency band and pulse width of the first pulse optical signal and the updated frequency band and pulse width of the second pulse optical signal, and sending a second control signal to indicate the updated power of the third pulse optical signal and the updated power of the fourth pulse optical signal to the power adjusting unit.

5. The measuring device according to claim 1, further comprising a first laser beam splitting unit connected with the laser emitting unit and the laser processing unit;

the first laser beam splitting unit is used for splitting the laser signal generated by the laser emitting unit into a first laser signal and a second laser signal and inputting the first laser signal into the laser processing unit;

the power adjusting unit is used for adjusting the power of the first pulse light signal to obtain a third pulse light signal with the power smaller than the stimulated Brillouin threshold, and adjusting the power of the second pulse light signal to obtain a fourth pulse light signal with the power smaller than the stimulated Brillouin threshold;

the first laser beam splitting unit is further used for inputting the second laser signal into the data processing unit;

the data processing unit is further configured to perform coherent detection on the first scattered light and the second scattered light according to the second laser signal, obtain vibration information of the sensing optical fiber according to an intensity and/or a phase of an optical signal obtained after the coherent detection of the first scattered light, and obtain a temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to an intensity and/or a frequency shift of an optical signal obtained after the coherent detection of the second scattered light.

6. The measurement device according to any one of claims 1 to 4, wherein the measurement device comprises a first laser beam splitting unit and a swept frequency processing unit; the first laser beam splitting unit is connected with the laser emitting unit, and the sweep frequency processing unit is connected with the first laser beam splitting unit and the sensing optical fiber;

the first laser beam splitting unit is used for splitting the laser signal generated by the laser emitting unit into a first laser signal and a second laser signal and inputting the first laser signal into the laser processing unit;

the laser processing unit is specifically configured to convert the first laser signal into the pulsed light signal, and input the pulsed light signal into the power adjustment unit;

the power adjusting unit is used for adjusting the power of the first pulse light signal to obtain a third pulse light signal with the power smaller than the stimulated Brillouin threshold, and adjusting the power of the second pulse light signal to obtain a fourth pulse light signal with the power larger than the stimulated Brillouin threshold;

the frequency sweep processing unit is used for carrying out frequency sweep processing on the second laser signal and inputting the detection light obtained after the frequency sweep processing into the sensing optical fiber;

the optical coupling unit is further configured to receive the second scattered light obtained by stimulated brillouin scattering amplification of the probe light and the fourth pulsed light signal in the sensing optical fiber, and the first scattered light generated by the third pulsed light signal in the sensing optical fiber.

7. The measurement device according to any one of claims 1 to 4, wherein the measurement device comprises a first laser beam splitting unit, a second laser beam splitting unit and a sweep frequency processing unit; the first laser beam splitting unit is connected with the laser emitting unit, the second laser beam splitting unit is connected with the first laser beam splitting unit, and the sweep frequency processing unit is connected with the second laser beam splitting unit and the sensing optical fiber;

the first laser beam splitting unit is used for splitting laser generated by the laser emitting unit into a first laser signal and a second laser signal and inputting the first laser signal into the laser processing unit;

the laser processing unit is specifically configured to convert the first laser signal into the pulsed light signal, and input the pulsed light signal into the power adjustment unit;

the power adjusting unit is used for adjusting the power of the first pulse light signal to obtain a third pulse light signal with the power smaller than the stimulated Brillouin threshold, and adjusting the power of the second pulse light signal to obtain a fourth pulse light signal with the power larger than the stimulated Brillouin threshold;

the first laser beam splitting unit is further used for inputting the second laser signal into the second laser beam splitting unit;

the second laser beam splitting unit is used for splitting the second laser signal into a third laser signal and a fourth laser signal, inputting the third laser signal into the sweep frequency processing unit, and inputting the fourth laser signal into the data processing unit;

the frequency sweep processing unit is used for carrying out frequency sweep processing on the third laser signal and inputting the detection light obtained after the frequency sweep processing into the sensing optical fiber;

the optical coupling unit is further configured to receive the second scattered light obtained by stimulated brillouin scattering amplification of the probe light and the fourth pulsed light signal in the sensing optical fiber and the first scattered light generated by the third pulsed light signal in the sensing optical fiber;

the data processing unit is further configured to perform coherent detection on the first scattered light and the second scattered light according to the fourth laser signal, obtain vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtain the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the frequency shift of the optical signal obtained after the coherent detection of the second scattered light.

8. A measuring device according to any of claims 1-5, characterized in that the power conditioning unit is a semiconductor optical amplifier SOA or an optical switch OS.

9. The measurement device of claim 8, wherein the power conditioning unit further comprises an Erbium Doped Fiber Amplifier (EDFA).

10. A measuring device according to any of claims 1-5, characterized in that the laser processing unit comprises an acousto-optical modulator AOM.

11. The measurement device according to claim 10, wherein the laser processing unit further comprises an electro-optical modulator EOM.

12. A method of measurement, comprising:

generating a laser signal and converting the laser signal into a pulse light signal which appears periodically; the pulse light signals comprise a first pulse light signal and a second pulse light signal, the frequency bands of the first pulse light signal and the second pulse light signal are different, and the occurrence time of the first pulse light signal and the second pulse light signal is different;

performing power adjustment on the first pulse light signal to obtain a third pulse light signal, performing power adjustment on the second pulse light signal to obtain a fourth pulse light signal, and inputting the third pulse light signal and the fourth pulse light signal into a sensing optical fiber;

and receiving first scattered light generated in the sensing optical fiber by the third pulsed light signal and second scattered light generated in the sensing optical fiber by the fourth pulsed light signal, and obtaining information of the sensing optical fiber according to the first scattered light and the second scattered light.

13. The measurement method according to claim 12, wherein the power of the third pulsed light signal is less than a stimulated brillouin threshold and the power of the fourth pulsed light signal is greater than the stimulated brillouin threshold, or wherein the power of the third pulsed light signal and the power of the fourth pulsed light signal are both less than the stimulated brillouin threshold.

14. The measurement method according to claim 13, wherein the obtaining information of the sensing fiber from the first scattered light and the second scattered light specifically comprises:

converting the first scattered light into a first electrical signal and converting the second scattered light into a second electrical signal;

converting the first electrical signal into a first digital signal and converting the second electrical signal into a second digital signal;

and demodulating the first digital signal to obtain vibration information of the sensing optical fiber, and demodulating the second digital signal to obtain temperature and deformation information of the sensing optical fiber.

15. The measurement method of claim 12, wherein after the generating the laser signal, the method further comprises:

dividing the laser signal into a first laser signal and a second laser signal;

then, the converting the laser signal into a periodically appearing pulsed light signal specifically includes:

converting the first laser signal into the pulsed light signal.

16. The method according to claim 15, wherein the obtaining vibration information of the sensing fiber from the first scattered light and obtaining temperature and deformation information of the sensing fiber from the second scattered light specifically comprises:

performing coherent detection on the first scattered light and the second scattered light according to the second laser signal, obtaining vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtaining the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the intensity and/or frequency shift of an optical signal obtained after the coherent detection of the second scattered light;

wherein the power of the third pulsed light signal generating the first scattered light is less than the stimulated brillouin threshold, and the power of the fourth pulsed light signal generating the second scattered light is less than the stimulated brillouin threshold.

17. The measurement method of claim 15, wherein after the splitting the laser signal into a first laser signal and a second laser signal, the method further comprises:

performing frequency sweep processing on the second laser signal, and inputting the probe light obtained after the frequency sweep processing into the sensing optical fiber, so that the probe light and the fourth pulse optical signal generate stimulated brillouin scattering amplification in the sensing optical fiber to obtain the second scattered light; the power of the third pulse light signal is smaller than the stimulated Brillouin threshold, and the power of the fourth pulse light signal is larger than the stimulated Brillouin threshold.

18. The measurement method of claim 15, wherein after the splitting the laser signal into a first laser signal and a second laser signal, the method further comprises:

dividing the second laser signal into a third laser signal and a fourth laser signal, performing frequency sweep processing on the third laser signal, and inputting the probe light obtained after the frequency sweep processing into the sensing optical fiber, so that the probe light and the fourth pulse optical signal are subjected to stimulated brillouin scattering amplification in the sensing optical fiber to obtain the second scattered light.

19. The method according to claim 17, wherein the obtaining vibration information of the sensing fiber from the first scattered light and obtaining temperature and deformation information of the sensing fiber from the second scattered light specifically comprises:

performing coherent detection on the first scattered light and the second scattered light according to the fourth laser signal, obtaining vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtaining the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the frequency shift of the optical signal obtained after the coherent detection of the second scattered light;

wherein the power of the third pulsed light signal generating the first scattered light is less than the stimulated Brillouin threshold, and the power of the fourth pulsed light signal generating the second scattered light is greater than the stimulated Brillouin threshold.

20. The measurement method according to any one of claims 12-19, characterized in that the method further comprises:

updating the frequency band and the pulse width of the first pulse optical signal and the power of the third pulse optical signal according to the obtained vibration information of the sensing optical fiber; updating the frequency band and the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal according to the obtained temperature and deformation information of the sensing optical fiber;

the generated laser signals are converted into pulse light signals according to the updated frequency band and pulse width of the first pulse light signals and the updated frequency band and pulse width of the second pulse light signals, power adjustment is carried out on the first pulse light signals in the pulse light signals according to the updated power of the third pulse light signals, and power adjustment is carried out on the second pulse light signals in the pulse light signals according to the updated power of the fourth pulse light signals.

Background

The distributed optical fiber sensing technology is to use the optical fiber as a sensor, obtain external information on an optical fiber path according to the intensity, phase or frequency shift of scattered light of each point on the measured optical fiber, and realize the monitoring of an optical fiber network. Because the optical fiber has the advantages of small volume, light weight, high sensitivity, electric insulation, environmental resistance and the like, the distributed optical fiber sensing technology is widely applied to the Internet of things, the neural network of a safe city and the like.

In a conventional distributed optical fiber sensing technology, a measuring device generates a pulse light with a fixed frequency shift in one cycle, and the pulse light generates rayleigh scattered light and brillouin scattered light in a sensing optical fiber. Because the frequencies of the rayleigh scattered light and the brillouin scattered light are completely staggered, the measuring device can demodulate the rayleigh scattered light and the brillouin scattered light respectively. The measuring device demodulates Rayleigh scattering light to obtain the vibration of the sensing optical fiber, and demodulates Brillouin scattering light to obtain the temperature on an optical line and the deformation of the optical fiber. However, the pulse width, the pulse optical power, and the like cannot be independently adjusted according to the respective requirements of the rayleigh scattered light and the brillouin scattered light, and the measurement accuracy of the optical measurement device is greatly reduced.

Disclosure of Invention

The embodiment of the application provides a measurement method and a measurement device, which can independently adjust pulsed light according to respective requirements of Rayleigh scattered light and Brillouin scattered light, and improve the measurement precision of the measurement device.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, a measurement device is disclosed, comprising: the laser processing device comprises a laser emitting unit, a laser processing unit, a power adjusting unit, an optical coupling unit and a data processing unit. The laser emitting unit is connected with the laser processing unit, the laser processing unit is connected with the power adjusting unit, the power adjusting unit is connected with the optical coupling unit, and the optical coupling unit is connected with the data processing unit. In a specific implementation, the laser emitting unit is used for generating a laser signal and inputting the laser signal into the laser processing unit; the light processing unit is used for converting the laser signal input by the laser emitting unit into a pulse light signal which appears periodically and inputting the pulse light signal into the power adjusting unit. The pulse light signals converted by the laser processing unit comprise first pulse light signals and second pulse light signals, the frequency bands of the first pulse light signals and the second pulse light signals are different, and the time of the first pulse light signals and the time of the second pulse light signals are different. The power adjusting unit is used for adjusting the power of the first pulse light signal input by the laser processing unit to obtain a third pulse light signal and adjusting the power of the second pulse light signal input by the laser processing unit to obtain a fourth pulse light signal; the power of the third pulse light signal is smaller than the stimulated Brillouin threshold value, and the power of the fourth pulse light signal is larger than the stimulated Brillouin threshold value, or both the power of the third pulse light signal and the power of the fourth pulse light signal are smaller than the stimulated Brillouin threshold value. The power adjusting unit is further used for inputting the third pulse light signal and the fourth pulse light signal into the optical coupling unit. The optical coupling unit is used for inputting a third pulse optical signal and a fourth pulse optical signal into the sensing optical fiber and receiving first scattered light generated by the third pulse optical signal in the sensing optical fiber and second scattered light generated by the fourth pulse optical signal in the sensing optical fiber; the first scattered light and the second scattered light are input to a data processing unit. The data processing unit is used for obtaining vibration information of the sensing optical fiber according to the first scattered light; and obtaining the temperature and deformation information of the sensing optical fiber according to the second scattered light.

Therefore, the embodiment of the invention adopts frequency division multiplexing and time division multiplexing technologies, the measuring device can generate two pulsed lights with different frequency bands at different times in a period, and the two pulsed lights are respectively used for measuring the vibration of the sensing optical fiber and the temperature/deformation of the sensing optical fiber. Meanwhile, aiming at the requirements of Rayleigh scattering measurement on the vibration information of the sensing optical fiber and Brillouin scattering measurement on the temperature/deformation of the sensing optical fiber, the measuring device independently optimizes and adjusts the peak power of the two groups of pulses. In addition, the backward Rayleigh scattering light and the Brillouin scattering light generated in the sensing optical fiber are staggered in frequency, the measuring device can be used for distinguishing by adopting various methods and respectively demodulating, and meanwhile, the dynamic vibration and static temperature/deformation information of the sensing optical fiber are obtained. Therefore, the embodiment of the invention can measure the dynamic vibration and the static temperature/strain of the sensing optical fiber while sharing the photoelectric device, thereby reducing the cost to the greatest extent. In addition, the embodiment of the invention can independently adjust the power and the pulse width of two groups of pulses, can optimize aiming at different application scenes, and greatly improves the measurement precision.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the data processing unit includes: photoelectric detection unit, data acquisition unit and system control unit. The photoelectric detection unit is used for receiving the first scattered light and the second scattered light, converting the first scattered light into a first electric signal and converting the second scattered light into a second electric signal; and the first electrical signal and the second electrical signal are input into a data acquisition unit. The data acquisition unit is used for receiving the first electric signal and the second electric signal, converting the first electric signal into a first digital signal and converting the second electric signal into a second digital signal; and inputs the first digital signal and the second digital signal to the system control unit. The system control unit is used for receiving the first digital signal and the second digital signal, demodulating the first digital signal to obtain vibration information of the sensing optical fiber, and demodulating the second digital signal to obtain temperature and deformation information of the sensing optical fiber.

The embodiment of the invention also provides a specific hardware composition of the data processing unit, which can perform photoelectric conversion, analog-to-digital conversion and the like on the scattered light, and finally determine the information of the sensing optical fiber according to the digital signal.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the system control unit is connected to the laser processing unit and the power adjusting unit. The system control unit is further used for updating the frequency band of the first pulse optical signal, the pulse width of the first pulse optical signal and the power of the third pulse optical signal according to the obtained vibration information of the sensing optical fiber; and updating the frequency band of the second pulse optical signal, the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal according to the obtained temperature and deformation information of the sensing optical fiber. The system control unit is further configured to send a first control signal to the laser processing unit to indicate the updated frequency band of the first pulsed light signal, the updated pulse width of the first pulsed light signal, the updated frequency band of the second pulsed light signal, and the updated pulse width of the second pulsed light signal, and send a second control signal to indicate the updated power of the third pulsed light signal and the updated power of the fourth pulsed light signal to the power adjusting unit.

In the embodiment of the present invention, the measurement device may further adjust subsequent measurement actions according to previous measurement results, such as: controlling the modulation result of the periodic pulse optical signal and controlling the power regulation result.

With reference to the first aspect, in a third possible implementation manner of the first aspect, the measuring apparatus further includes a first laser beam splitting unit, and the first laser beam splitting unit is connected to the laser emitting unit and the laser processing unit. The first laser beam splitting unit is used for splitting the laser signal generated by the laser emitting unit into a first laser signal and a second laser signal and inputting the first laser signal into the laser processing unit. The laser processing unit is also used for converting the first laser signal into a pulse light signal and inputting the pulse light signal into the power adjusting unit. The power adjusting unit is used for obtaining a third pulse light signal with the power smaller than the stimulated Brillouin threshold and a fourth pulse light signal with the power smaller than the stimulated Brillouin threshold according to the pulse light signals. The first laser beam splitting unit is also used for inputting a second laser signal into the data processing unit. The data processing unit is further used for carrying out coherent detection on the first scattered light and the second scattered light according to the second laser signal, obtaining vibration information of the sensing optical fiber according to the intensity and/or the phase of an optical signal obtained after the coherent detection of the first scattered light, and obtaining the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the intensity and/or the frequency shift of the optical signal obtained after the coherent detection of the second scattered light.

In the embodiment of the present invention, information of the sensing optical fiber can be obtained by using rayleigh scattering and brillouin scattering generated in the sensing optical fiber by the pulsed light signal, such as: vibration information, temperature, deformation information, etc. And coherent detection can be carried out on scattered light generated by the pulsed light signals by introducing local oscillator light. Specifically, there is a difference (about 11GHz) between the rayleigh scattered light generated by the third pulsed light signal and the brillouin scattered light generated by the fourth pulsed light signal in the optical frequency band, the two scattered lights and the local oscillator light are interfered by coherent detection, the interfered optical signal is received by a photoelectric detector (for example, the photoelectric detection unit according to the embodiment of the present invention), the received optical signal can be converted into an electrical signal by the photoelectric detector, and the two electrical signals corresponding to the two scattered lights are different in the electrical frequency band, so that the two electrical signals can be directly distinguished.

With reference to the first aspect or the first or second possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the measuring device includes a first laser beam splitting unit and a sweep frequency processing unit; the first laser beam splitting unit is connected with the laser emitting unit, and the sweep frequency processing unit is connected with the first laser beam splitting unit and the sensing optical fiber. Specifically, the first laser beam splitting unit is configured to split the laser signal generated by the laser emitting unit into a first laser signal and a second laser signal, and input the first laser signal to the laser processing unit. The laser processing unit is specifically configured to convert the first laser signal into a pulsed light signal, and input the pulsed light signal to the power adjustment unit. The power adjusting unit is used for obtaining a third pulse light signal with the power smaller than the stimulated Brillouin threshold and a fourth pulse light signal with the power larger than the stimulated Brillouin threshold according to the pulse light signals. And the frequency sweep processing unit is used for carrying out frequency sweep processing on the second laser signal and inputting the detection light obtained after the frequency sweep processing into the sensing optical fiber. The optical coupling unit is further used for receiving second scattered light obtained by stimulated Brillouin scattering amplification of the probe light and the fourth pulse light signal in the sensing optical fiber and first scattered light generated by the third pulse light signal in the sensing optical fiber.

In the embodiment of the present invention, information of the sensing optical fiber may be obtained by utilizing rayleigh scattering generated in the sensing optical fiber by the pulsed light signal and scattered light obtained by stimulated brillouin amplification of the pulsed light signal, such as: vibration information, temperature, deformation information, etc.

With reference to the first aspect or the first or second possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, the measuring device includes a first laser beam splitting unit, a second laser beam splitting unit, and a sweep frequency processing unit. The first laser beam splitting unit is connected with the laser emitting unit, the second laser beam splitting unit is connected with the first laser beam splitting unit, and the sweep frequency processing unit is connected with the second laser beam splitting unit and the sensing optical fiber. In a specific implementation, the first laser beam splitting unit is configured to split laser generated by the laser emitting unit into a first laser signal and a second laser signal, and input the first laser signal to the laser processing unit. The laser processing unit is specifically configured to convert the first laser signal into a pulsed light signal, and input the pulsed light signal to the power adjustment unit. The power adjusting unit is used for obtaining a third pulse light signal with the power smaller than the stimulated Brillouin threshold and a fourth pulse light signal with the power larger than the stimulated Brillouin threshold according to the pulse light signals. The first laser beam splitting unit is further used for inputting a second laser signal into the second laser beam splitting unit. The second laser beam splitting unit is used for splitting the second laser signal into a third laser signal and a fourth laser signal, inputting the third laser signal into the frequency sweep processing unit, and inputting the fourth laser signal into the data processing unit. And the frequency sweep processing unit is used for carrying out frequency sweep processing on the third laser signal and inputting the detection light obtained after the frequency sweep processing into the sensing optical fiber. The optical coupling unit is further used for receiving second scattered light obtained by stimulated Brillouin scattering amplification of the probe light and the fourth pulse light signal in the sensing optical fiber and first scattered light generated by the third pulse light signal in the sensing optical fiber. The data processing unit is further configured to perform coherent detection on the first scattered light and the second scattered light according to the fourth laser signal, obtain vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtain the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the frequency shift of the optical signal obtained after the coherent detection of the second scattered light.

In the embodiment of the present invention, information of the sensing optical fiber may be obtained by utilizing rayleigh scattering generated in the sensing optical fiber by the pulsed light signal and scattered light obtained by stimulated brillouin amplification of the pulsed light signal, such as: vibration information, temperature, deformation information, etc. The Rayleigh scattered light generated by the third pulse light signal and the Brillouin scattered light generated by the fourth pulse light signal have difference (about 11GHz) in the optical frequency range, the two scattered lights and the local oscillator light are interfered by coherent detection, the interfered optical signals are received by the photoelectric detector, the received optical signals can be converted into electric signals by the photoelectric detector, and the two electric signals corresponding to the two scattered lights have difference in the electrical frequency range, so that the two electric signals can be directly distinguished.

With reference to the first aspect or any one of the first to fifth possible implementation manners of the first aspect, in a sixth possible implementation manner of the first aspect, the power adjusting unit is a semiconductor optical amplifier SOA or an optical switch OS.

With reference to any one of the sixth possible implementation manners of the first aspect, in a seventh possible implementation manner of the first aspect, the power conditioning unit further includes an erbium-doped fiber amplifier EDFA.

With reference to the first aspect or any one of the first to seventh possible implementation manners of the first aspect, in an eighth possible implementation manner of the first aspect, the laser processing unit includes an acousto-optic modulator AOM.

With reference to any one of the eighth possible implementation manners of the first aspect, in a ninth possible implementation manner of the first aspect, the laser processing unit further includes an electro-optical modulator EOM.

In a second aspect, a measurement method is disclosed, comprising: the measuring device firstly generates a laser signal and converts the laser signal into a pulse light signal which appears periodically; the pulse light signals comprise a first pulse light signal and a second pulse light signal, the frequency bands of the first pulse light signal and the second pulse light signal are different, and the time of occurrence of the first pulse light signal and the time of occurrence of the second pulse light signal are different. Then, the measuring device adjusts the power of the first pulse light signal to obtain a third pulse light signal, adjusts the power of the second pulse light signal to obtain a fourth pulse light signal, and inputs the third pulse light signal and the fourth pulse light signal into the sensing optical fiber; the power of the third pulse light signal is smaller than the stimulated Brillouin threshold value, and the power of the fourth pulse light signal is larger than the stimulated Brillouin threshold value, or the power of the third pulse light signal and the power of the fourth pulse light signal are both smaller than the stimulated Brillouin threshold value. Finally, first scattered light generated by the third pulse light signal in the sensing optical fiber and second scattered light generated by the fourth pulse light signal in the sensing optical fiber can be received, vibration information of the sensing optical fiber can be obtained according to the first scattered light, and temperature and deformation information of the sensing optical fiber can be obtained according to the second scattered light.

The embodiment of the invention adopts frequency division multiplexing and time division multiplexing technologies, the measuring device can generate two pulse lights with different frequency bands at different times in a period, and the two pulse lights are respectively used for measuring the vibration of the sensing optical fiber and the temperature/deformation of the sensing optical fiber. Meanwhile, aiming at the requirements of Rayleigh scattering measurement on the vibration information of the sensing optical fiber and Brillouin scattering measurement on the temperature/deformation of the sensing optical fiber, the measuring device independently optimizes and adjusts the peak power of the two groups of pulses. In addition, the backward Rayleigh scattering light and the Brillouin scattering light generated in the sensing optical fiber are staggered in frequency, the measuring device can be used for distinguishing by adopting various methods and respectively demodulating, and meanwhile, the dynamic vibration and static temperature/deformation information of the sensing optical fiber are obtained. Therefore, the embodiment of the invention can measure the dynamic vibration and the static temperature/strain of the sensing optical fiber while sharing the photoelectric device, thereby reducing the cost to the greatest extent. In addition, the embodiment of the invention can independently adjust the power and the pulse width of two groups of pulses, can optimize aiming at different application scenes, and greatly improves the measurement precision.

With reference to the first possible implementation manner of the second aspect, in a first possible implementation manner of the second aspect, the obtaining, by the measuring device, vibration information of the sensing optical fiber according to the first scattered light, and obtaining temperature and deformation information of the sensing optical fiber according to the second scattered light specifically includes: converting the first scattered light into a first electrical signal and converting the second scattered light into a second electrical signal; converting the first electrical signal into a first digital signal and converting the second electrical signal into a second digital signal; and demodulating the first digital signal to obtain vibration information of the sensing optical fiber, and demodulating the second digital signal to obtain temperature and deformation information of the sensing optical fiber.

The embodiment of the invention can perform photoelectric conversion, analog-to-digital conversion and the like on the scattered light, and finally determine the information of the sensing optical fiber according to the digital signal.

With reference to the second aspect, in a second possible implementation manner of the second aspect, after the measuring device generates the laser signal, the laser signal may be further divided into a first laser signal and a second laser signal; then, converting the laser signal into the periodically appearing pulsed light signal specifically includes: the first laser signal is converted into a pulsed optical signal.

With reference to the second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, the obtaining vibration information of the sensing optical fiber according to the first scattered light, and the obtaining temperature and deformation information of the sensing optical fiber according to the second scattered light specifically includes: and carrying out coherent detection on the first scattered light and the second scattered light according to the second laser signal, obtaining vibration information of the sensing optical fiber according to the intensity and/or phase of the optical signal obtained after the coherent detection of the first scattered light, and obtaining the temperature of the sensing optical fiber and the deformation information of the sensing optical fiber according to the intensity and/or frequency shift of the optical signal obtained after the coherent detection of the second scattered light. The power of a third pulse light signal for generating the first scattered light is smaller than the stimulated Brillouin threshold, and the power of a fourth pulse light signal for generating the second scattered light is smaller than the stimulated Brillouin threshold.

In the embodiment of the present invention, information of the sensing optical fiber can be obtained by using rayleigh scattering and brillouin scattering generated in the sensing optical fiber by the pulsed light signal, such as: vibration information, temperature, deformation information, etc. In the embodiment of the invention, the difference (about 11GHz) exists between the Rayleigh scattered light generated by the third pulse light signal and the Brillouin scattered light generated by the fourth pulse light signal in the optical frequency band, the two scattered lights and the local oscillator light are interfered by coherent detection, the interfered optical signal is received by the photoelectric detector, the received optical signal can be converted into the electric signal by the photoelectric detector, and the two electric signals corresponding to the two scattered lights have the difference in the electric frequency band, so that the two electric signals can be directly distinguished.

With reference to the second possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, after dividing the laser signal into a first laser signal and a second laser signal, the method further includes: and performing frequency sweep processing on the second laser signal, and inputting the detection light obtained after the frequency sweep processing into the sensing optical fiber so as to facilitate the detection light and the fourth pulse optical signal to generate stimulated Brillouin scattering amplification in the sensing optical fiber to obtain second scattered light. In this implementation, the power of the third pulse light signal is smaller than the stimulated brillouin threshold, and the power of the fourth pulse light signal is larger than the stimulated brillouin threshold.

In the embodiment of the present invention, information of the sensing optical fiber may be obtained by utilizing rayleigh scattering generated in the sensing optical fiber by the pulsed light signal and scattered light obtained by stimulated brillouin amplification of the pulsed light signal, such as: vibration information, temperature, deformation information, etc.

With reference to the second possible implementation manner of the second aspect, in a fifth possible implementation manner of the second aspect, after dividing the laser signal into the first laser signal and the second laser signal, the method further includes: and dividing the second laser signal into a third laser signal and a fourth laser signal, performing frequency sweep processing on the third laser signal, and inputting the probe light obtained after the frequency sweep processing into the sensing optical fiber so as to facilitate the stimulated Brillouin scattering amplification of the probe light and the fourth pulse optical signal in the sensing optical fiber to obtain second scattered light.

With reference to the fifth possible implementation manner of the second aspect, in a sixth possible implementation manner of the second aspect, the obtaining vibration information of the sensing optical fiber according to the first scattered light, and the obtaining temperature and deformation information of the sensing optical fiber according to the second scattered light specifically includes: coherent detection is carried out on the first scattered light and the second scattered light according to the fourth laser signal, vibration information of the sensing optical fiber is obtained according to the intensity and/or the phase of an optical signal obtained after the coherent detection of the first scattered light, and the temperature of the sensing optical fiber and deformation information of the sensing optical fiber are obtained according to the frequency shift of the optical signal obtained after the coherent detection of the second scattered light; the power of a third pulse light signal for generating the first scattered light is smaller than the stimulated Brillouin threshold, and the power of a fourth pulse light signal for generating the second scattered light is larger than the stimulated Brillouin threshold.

In the embodiment of the present invention, information of the sensing optical fiber may be obtained by utilizing rayleigh scattering generated in the sensing optical fiber by the pulsed light signal and scattered light obtained by stimulated brillouin amplification of the pulsed light signal, such as: vibration information, temperature, deformation information, etc. It should be noted that there is a difference (about 11GHz) between the optical frequency band of the rayleigh scattered light generated by the third pulsed optical signal and the optical frequency band of the brillouin scattered light generated by the fourth pulsed optical signal itself, in the embodiment of the present invention, the two scattered lights and the local oscillator light interfere with each other through coherent detection, the optical signal after the interference is received by the photodetector, the photodetector can convert the received optical signal into an electrical signal, and the two electrical signals corresponding to the two scattered lights generate a difference in the electrical frequency band, so that the two electrical signals can be directly distinguished.

With reference to the second aspect or any one of the first to sixth possible implementation manners of the second aspect, in a seventh possible implementation manner of the second aspect, the measuring device may further update the frequency band of the first pulsed light signal, the pulse width of the first pulsed light signal, and the power of the third pulsed light signal according to the obtained vibration information of the sensing optical fiber; updating the frequency band of the second pulse optical signal, the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal according to the obtained temperature and deformation information of the sensing optical fiber; the generated laser signals are converted into pulse light signals according to the updated frequency band of the first pulse light signal, the updated pulse width of the first pulse light signal, the updated frequency band of the second pulse light signal and the updated pulse width of the second pulse light signal, the power of the first pulse light signal in the pulse light signals is adjusted according to the updated power of the third pulse light signal, and the power of the second pulse light signal in the pulse light signals is adjusted according to the updated power of the fourth pulse light signal.

In the embodiment of the present invention, the measurement device may further adjust subsequent measurement actions according to previous measurement results, such as: controlling the modulation result of the periodic pulse optical signal and controlling the power regulation result.

Drawings

Fig. 1 is an architecture diagram of an optical fiber communication system provided by an embodiment of the present application;

fig. 2 is a block diagram of a measuring apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a pulsed optical signal provided by an embodiment of the present invention;

FIG. 4 is another block diagram of a measuring device according to an embodiment of the present invention;

FIG. 5 is another block diagram of a measuring device according to an embodiment of the present invention;

FIG. 6 is another block diagram of a measuring device according to an embodiment of the present invention;

FIG. 7 is another block diagram of a measuring device according to an embodiment of the present invention;

FIG. 8 is another block diagram of a measuring device according to an embodiment of the present invention;

fig. 9 is another block diagram of a measuring apparatus according to an embodiment of the present invention;

FIG. 10 is another schematic diagram of a pulsed optical signal provided by an embodiment of the present invention;

fig. 11 is another structural block diagram of the measuring apparatus according to the embodiment of the present invention;

fig. 12 is a schematic flowchart of a measurement method according to an embodiment of the present invention.

Detailed Description

In the optical fiber communication system shown in fig. 1, both communication parties perform signal transmission and signal reception through an optical fiber, and the measurement device provided by the embodiment of the present invention can be connected to the optical fiber between both communication parties. Specifically, the measuring device may measure information related to the optical fiber between the two communicating parties, such as: vibration information, temperature, deformation information, etc. of the optical fiber. Furthermore, the measuring device can monitor the state of the optical fiber according to the obtained information of the optical fiber, timely process invasion, faults and the like, and avoid influencing the communication of the two parties to a certain extent.

The embodiment of the invention adopts frequency division multiplexing and time division multiplexing technologies, the measuring device can generate two pulse lights with different frequency bands at different times in a period, and the two pulse lights are respectively used for measuring the vibration of the sensing optical fiber and the temperature/deformation of the sensing optical fiber. Meanwhile, aiming at the requirements of Rayleigh scattering measurement on the vibration information of the sensing optical fiber and Brillouin scattering measurement on the temperature/deformation of the sensing optical fiber, the measuring device independently optimizes and adjusts the peak power of the two groups of pulses. In addition, the backward Rayleigh scattering light and the Brillouin scattering light generated in the sensing optical fiber are staggered in frequency, the measuring device can be used for distinguishing by adopting various methods and respectively demodulating, and meanwhile, the dynamic vibration and static temperature/deformation information of the sensing optical fiber are obtained. Therefore, the embodiment of the invention can measure the dynamic vibration and the static temperature/strain of the sensing optical fiber while sharing the photoelectric device, thereby reducing the cost to the greatest extent. In addition, the embodiment of the invention can independently adjust the power and the pulse width of two groups of pulses, can optimize aiming at different application scenes, and greatly improves the measurement precision.

An embodiment of the present invention provides a measurement apparatus, as shown in fig. 2, the measurement apparatus includes: a laser emitting unit 201, a laser processing unit 202, a power adjusting unit 203, an optical coupling unit 204, and a data processing unit 205. Referring to fig. 2, the laser emitting unit 201 is connected to the laser processing unit 202, the laser processing unit 202 is connected to the power adjusting unit 203, the power adjusting unit 203 is connected to the optical coupling unit 204, and the optical coupling unit 204 is connected to the data processing unit 205.

In a specific implementation, the laser emitting unit 201 is configured to generate a continuous laser signal, and input the generated laser signal to the laser processing unit 202. The laser emitting unit 201 may be a laser (laser).

The laser processing unit 202 is used for frequency modulation and pulse modulation of the input laser signal. Specifically, the input laser signal is converted into a pulse light signal that appears periodically, and the pulse light signal is input to the power adjustment unit 203. Referring to fig. 3, the pulsed light signals include a first pulsed light signal and a second pulsed light signal, the frequency bands of the first pulsed light signal and the second pulsed light signal are different, the frequency band of the first pulsed light signal is f 1, and the frequency band of the second pulsed light signal is f 2. And the first pulse light signal and the second pulse light signal occur at different times. The laser processing unit 202 may be an AOM. In some embodiments, the laser processing unit 202 may further include an electro-Optical Modulator (EOM), that is, the laser processing unit 202 includes an AOM and an EOM, wherein the EOM load frequency-modulates the input pulsed Optical signal, and the AOM is responsible for pulse-modulating the input pulsed Optical signal.

The power adjusting unit 203 is configured to adjust the power of the two sets of pulsed light respectively. Specifically, the power of the first pulsed light signal input by the laser processing unit 202 is adjusted to obtain a third pulsed light signal, and the power of the second pulsed light signal input by the laser processing unit is adjusted to obtain a fourth pulsed light signal. It should be noted that, if the measurement device obtains the vibration information of the optical fiber by using the rayleigh scattered light of the third pulsed light signal, the third pulsed light signal needs to satisfy the following conditions: the power of the third pulse optical signal is smaller than the stimulated Brillouin threshold; if the measuring device obtains the temperature and deformation information of the optical fiber by using the spontaneous brillouin scattering light of the fourth pulse optical signal, the fourth pulse optical signal needs to satisfy the following conditions: the power of the fourth pulse optical signal is smaller than the stimulated Brillouin threshold; if the measuring device determines the temperature and deformation information of the optical fiber by using the scattered light obtained by the stimulated brillouin scattering of the fourth pulse optical signal, the fourth pulse optical signal needs to satisfy the following conditions: the power of the fourth pulse optical signal is larger than the stimulated Brillouin threshold.

Subsequently, the power adjusting unit 203 may also input the third pulsed light signal and the fourth pulsed light signal to the optical coupling unit. The power adjusting unit 203 may be a Semiconductor Optical Amplifier (SOA) or an Optical Switch (OS). In some embodiments, power conditioning unit 203 may also include an Erbium-Doped Fiber Amplifier (EDFA).

The optical coupling unit 204 is configured to input a pulsed light signal into the sensing fiber and input scattered light generated by the pulsed light in the sensing fiber into the data processing unit 205 for processing. Specifically, the third pulse light signal and the fourth pulse light signal are input into a sensing optical fiber, and first scattered light generated in the sensing optical fiber by the third pulse light signal and second scattered light generated in the sensing optical fiber by the fourth pulse light signal are received. In addition, the optical coupling unit 204 may also input the first scattered light and the second scattered light to the data processing unit 205. The optical coupling unit may be an optical coupler or an optical circulator.

The data processing unit 205 is configured to obtain vibration information of the sensing optical fiber according to the first scattered light; and obtaining the temperature and deformation information of the sensing optical fiber according to the second scattered light. It should be noted that, in the embodiment of the present invention, the deformation information is used to indicate whether the sensing optical fiber is deformed and the size of the deformation, and the deformation of the sensing optical fiber may be a change in the shape of the sensing optical fiber under the stress action, such as: changes such as elongation and contraction of the sensing fiber. The vibration information is used for indicating whether the sensing optical fiber vibrates or not, and the strength, frequency, phase and the like of the vibration, and the vibration of the sensing optical fiber can be the deformation of the sensing optical fiber which changes rapidly and dynamically.

In the embodiment of the present invention, the first scattered light may be rayleigh scattered light generated in the sensing optical fiber by the optical pulse signal, and the second scattered light may be brillouin scattered light generated in the sensing optical fiber by the optical pulse signal. In general, Distributed Acoustic Sensing (DAS) technology can measure vibration of a sensing fiber using rayleigh scattered light, and Distributed Temperature Strain Sensing (DTSS) technology can measure Temperature and deformation of a sensing fiber using brillouin scattered light. That is to say, measuring device can utilize DAS technique to measure the vibration of sensing optical fiber, and measuring device can also utilize DTSS technique to measure the temperature and the deformation of sensing optical fiber, and further, can also infer the external change of optic fibre circuit according to vibration, temperature, the deformation of sensing optical fiber, in time discerns invasion, trouble etc. if: perimeter security protection, pipeline detection, train positioning and the like are realized by utilizing the detection device. The following describes the DAS and DTSS principles, respectively:

(1) when the optical fiber line is disturbed due to external vibration (intrusion, leakage, sound wave and the like), the refractive index of the sensing optical fiber at the disturbed position changes due to the photoelastic effect, so that the phase of scattered light at the disturbed position changes. Meanwhile, due to the interference effect of light, the intensity of the backward rayleigh scattered light is changed due to the phase change of the scattered light, so in the embodiment of the present invention, the data processing module 205 may demodulate a disturbance signal by detecting the intensity and the phase change of the rayleigh scattered light. Further, the data processing module 205 can accurately locate the distance of the disturbance signal according to the relationship between the transmission speed of the light in the optical fiber and the transmission time of the disturbance signal. The DAS technology includes a phase-sensitive optical time domain reflectometer (Φ -OTDR) technology and a time-gated digital optical frequency domain reflectometer (TGD-OFDR) technology.

In the phi-OTDR technology, the pulse optical signal input to the sensing fiber is a common pulse optical signal, and the spatial resolution of the measuring device is influenced by the pulse width of the pulse optical signal. Spatial resolutionWhere c is the speed of light in vacuum, τ is the pulse width of the pulsed light signal, and n is the refractive index of the optical fiber. It is obvious that a narrow pulse width is required to obtain a high spatial resolution, but too narrow a pulse width weakens scattered light and reduces the measurement accuracy of the measurement device, so that there is a constraint relationship between the spatial resolution and the measurement accuracy. In the embodiment of the present invention, the laser processing unit 202 is input with a continuous laser signal, and the laser processing unit 202 may convert the input laser signal into pulsed light that appears periodically, and two pulsed lights appear in one period. One pulse light is used for measuring vibration information of the sensing optical fiber, and the other pulse light is used for measuring temperature and deformation information of the sensing optical fiber. The laser processing unit 202 may appropriately control the pulse optical signal for measuring the vibration information of the sensing fiber, so that the pulse width of the pulse optical signal is not too wide or too narrow, and thus the spatial resolution and the measurement accuracy may be well equalized. It should be noted that spatial resolution is an important index in the optical fiber sensing technology, and refers to the minimum distance between two measurement points that can be identified by a measurement device.

In the TGD-OFDR technology, a sweep pulse optical signal is input into a sensing optical fiber,the spatial resolution is determined by the sweep range. Spatial resolutionThe method is not limited by the pulse width, and the spatial resolution and the measurement precision of the measuring device are not restricted mutually.

(2) When the optical fiber line deforms or changes in temperature due to the external environment, the frequency shift of the brillouin scattering light changes, and therefore long-distance and high-precision temperature and deformation sensing can be achieved by monitoring the frequency shift of the brillouin scattering light occurring in the sensing optical fiber. DTSS mainly includes two types: brillouin Optical Time Domain Reflectometry (BOTDR) based on spontaneous brillouin scattering light and Brillouin Optical Time Domain Analyzer (BOTDA) based on stimulated brillouin scattering.

In the BOTDR technology, optical pulse signals are injected into sensing optical fibers to spontaneously generate Brillouin scattering light, and a measuring device can obtain temperature/deformation information on the sensing optical fibers by detecting the frequency shift of the spontaneously Brillouin scattering light. However, the intensity of the spontaneous brillouin scattered light is weak, and is about 20dB lower than the rayleigh scattered light, and it is difficult to detect the light.

In the BOTDA technology, pulse light and sweep continuous light are respectively input into an optical fiber from two ends of the optical fiber, and when the frequency difference of the pulse light and the sweep continuous light is within the Brillouin gain spectrum range, the two light beams generate energy transfer through the stimulated Brillouin scattering effect. The temperature/deformation information along the sensing optical fiber can be obtained by measuring the stimulated Brillouin scattering gain spectrum of different positions of the sensing optical fiber and determining the Brillouin frequency shift. The stimulated Brillouin scattering light signal is stronger, and the measurement precision is obviously improved compared with the BOTDR.

In the embodiment of the invention, the DAS system and the DTSS system can be fused together, and the DAS system and the DTSS system share devices, so that not only can low cost be realized, but also the vibration, temperature and deformation of the sensing optical fiber can be simultaneously measured, and the new requirements of various industries on safe production can be met.

Referring to fig. 4, the data processing unit 205 may include a photodetection unit 2051, a data acquisition unit 2052, and a system control unit 2053.

In a specific implementation, the photoelectric detection unit 2051, the data acquisition unit 2052, and the system control unit 2053 cooperate to process the scattered light input by the optical coupling unit 204, so as to obtain vibration information, temperature, and deformation information of the sensing optical fiber.

Further, the Photo detection unit 2051 is used for converting an optical signal into an electrical signal, and may be a Photo Detector (PD) or a Balanced Photo Detector (BPD), or may be an Integrated Coherent Receiver (ICR). Specifically, the first scattered light and the second scattered light input by the optical coupling unit 204 are received, the first scattered light is converted into a first electrical signal, and the second scattered light is converted into a second electrical signal; and inputs the first electrical signal and the second electrical signal to the data acquisition unit 2052.

The data acquisition unit 2052 may be an analog-to-digital converter. Specifically, the data acquisition unit 2052 receives the first electrical signal and the second electrical signal input by the photodetection unit 2051, converts the first electrical signal into a first digital signal, and converts the second electrical signal into a second digital signal; and inputs the first digital signal and the second digital signal to the system control unit 2053.

The system control unit 2053 is configured to receive the first digital signal and the second digital signal input by the data acquisition unit, demodulate the first digital signal to obtain vibration information of the sensing optical fiber, and demodulate the second digital signal to obtain temperature and deformation information of the sensing optical fiber.

Referring to fig. 4, the system control unit 2053 may also be connected to the laser processing unit 202 and the power adjustment unit 203.

Initially, the system control unit 2053 sets a frequency band of the first pulse light signal, a pulse width of the first pulse light signal, a frequency band of the second pulse light signal, a pulse width of the second pulse light signal, a power of the third pulse light signal, and a power of the fourth pulse light signal. And the frequency band of the first pulse light signal, the pulse width of the first pulse light signal, the frequency band of the second pulse light signal, and the pulse width of the second pulse light signal are notified to the laser processing unit 202 by the control signal, so that the laser processing unit 202 generates the pulse light signals with corresponding pulse widths and frequency bands. The power of the third pulse light signal and the power of the fourth pulse light signal are notified to the power adjusting unit 203 by the control signal, so that the power adjusting unit 203 obtains the pulse light signals of the respective powers.

Further, the system control unit 2053 may also update the frequency band and the pulse width of the first pulse optical signal and the power of the third pulse optical signal according to the obtained vibration information of the sensing optical fiber; and according to the obtained temperature and deformation information of the sensing optical fiber, the frequency band and the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal. Specifically, the system control unit 2053 may analyze the obtained vibration information, and may update the current pulse width and frequency band of the first pulse light, and the current power of the third pulse light signal if the accuracy of the vibration information is low. The system control unit 2053 may also analyze the obtained deformation information (or temperature), and if the accuracy of the vibration information (or temperature) is low, the current pulse width and frequency band of the second pulse light and the current power of the fourth pulse light signal may be updated. It should be noted that, in the embodiment of the present invention, the accuracy of the information (e.g., vibration information, deformation information, and temperature of the optical fiber) refers to a proximity degree to an actual external environment of the sensing optical fiber, and the more the information can reflect the actual external environment of the sensing optical fiber, the higher the accuracy of the information is.

Further, the system control unit 2053 sends the first control signal to the laser processing unit 202 to indicate the updated frequency band of the first pulse light signal, the updated pulse width of the second pulse light signal, and the updated frequency band of the second pulse light signal, so that the laser processing unit 202 can modulate the laser signal into the pulse light signal with the specific frequency band and the specific pulse width according to the indication of the system control unit 2053, and the data processing unit 205 can obtain the vibration information with high accuracy according to the rayleigh scattering light generated by the pulse light signal. In addition, the system control unit 2053 may further send a second control signal to the power adjusting unit 203 to indicate the updated power of the third pulsed light signal and the updated power of the fourth pulsed light signal, and the power adjusting unit 203 may further adjust the received pulsed light signal according to the power indicated by the system control unit 2053.

Of course, if the accuracy of the vibration information is determined to be high after the vibration information is analyzed, the system control unit 2053 may not update the current configuration, such as: the current pulse width, the frequency range and the current power of the third pulse light signal of the first pulse light are not updated. Similarly, if the accuracy of the deformation information (or temperature) is determined to be high after the deformation information (or temperature) is analyzed, the system control unit 2053 may not update the current configuration, such as: the pulse width and the frequency range of the current second pulse light and the power of the current fourth pulse light signal are not updated.

In the measuring apparatus shown in fig. 2 or fig. 4, the laser processing unit 202 may convert the input continuous laser signal into two pulse light signals with a large frequency band difference, so that the data processing unit 205 may distinguish first scattered light generated by the two pulse light signals and also distinguish second scattered light generated by the two pulse light signals, and further the data processing unit 205 may demodulate vibration information of the sensing fiber generated by one of the pulse light signals and demodulate second scattered light generated by the other pulse light signal to obtain temperature and deformation information of the sensing fiber.

In some embodiments, a coherent detection technique may also be introduced, and a beam splitter may be used to split a laser signal into two paths, one path is used to input the sensing fiber to generate the first scattered light and the second scattered light, and the other path is used to perform coherent detection on the first scattered light and the second scattered light, so as to ensure that the data processing unit 205 can demodulate the first scattered light and the second scattered light respectively.

Specifically, referring to fig. 5, the measuring apparatus further includes a first laser beam splitting unit 206, and the laser beam splitting unit 206 may be a beam splitter or an optical coupler. The first laser beam splitting unit 206 is connected 202 with the laser emitting unit 201 and the laser processing unit.

In a specific implementation, the first laser beam splitting unit 206 is configured to split the laser signal generated by the laser emitting unit 201 into a first laser signal and a second laser signal, and the first laser signal split by the first laser beam splitting unit 206 generates scattered light, so that the first laser beam splitting unit 206 can input the first laser signal into the laser processing unit 202. The second laser signal is used as local oscillation light for coherent detection and is used for carrying out coherent detection on the scattered light.

The laser processing unit 202 is further configured to convert the first laser signal into the pulsed light signal, and input the pulsed light signal into the power adjusting unit 203.

The second laser signal split by the first laser beam splitting unit 206 is used for coherent detection of the scattered light, so the first laser beam splitting unit 206 can also input the second laser signal into the data processing unit 205.

The data processing unit 205 is further configured to perform coherent detection on the first scattered light input by the optical coupling unit 204 and the second scattered light input by the optical coupling unit 204 according to the second laser signal input by the first laser beam splitting unit 206. The rayleigh scattered light generated by the third pulse light signal and the brillouin scattered light generated by the fourth pulse light signal have difference (11 GHz) in the optical frequency band, so-called coherent detection means that the two scattered lights and the local oscillator light are interfered, the optical signal after interference is received by a photoelectric detector, the received optical signal can be converted into an electric signal by the photoelectric detector, and the two electric signals corresponding to the two scattered lights have difference in the electrical frequency band, so that the two electric signals can be directly distinguished. Alternatively, the two electrical signals may be converted into two digital signals by an analog-to-digital converter, and the two digital signals may be distinguished in the digital domain.

That is, the data processing unit 205 can also obtain the information of the sensing fiber according to the optical signal after coherent detection. Specifically, the vibration information of the sensing optical fiber is obtained according to the intensity and/or phase of the optical signal obtained after the coherent detection of the first scattered light, and the temperature of the sensing optical fiber and the deformation information of the sensing optical fiber are obtained according to the intensity and/or frequency shift of the optical signal obtained after the coherent detection of the second scattered light. In the embodiment of the present invention, the first scattered light may be rayleigh scattered light, and the second scattered light may be spontaneous brillouin scattered light, or scattered light obtained by occurrence of stimulated brillouin amplification.

Specifically, referring to fig. 6, the first laser beam splitting unit 206 may input the second laser signal into the photoelectric detection unit 2051 in the data processing unit 205, the photoelectric detection unit 2051 may perform coherent detection on the first scattered light and the second scattered light input by the optical coupling unit 204 according to the second laser signal, convert the coherent detected optical signal into an electrical signal, and input the electrical signal into the data acquisition unit 2052, the data acquisition unit 2052 may convert the electrical signal input by the photoelectric detection unit 2051 into a digital signal, and input the digital signal into the system control unit 2053, and the system control unit 2053 demodulates the digital signal to obtain the vibration information of the sensing optical fiber, the temperature of the sensing optical fiber, and the deformation information.

In some embodiments, the information of the sensing fiber can be monitored by fusing the phi-OTDR technology in the DAS and the BOTDA technology in the DTSS, or by fusing the TGD-OFDR technology in the DAS and the BOTDA technology in the DTSS. Because the BOTDA technology in the DTSS utilizes stimulated Brillouin scattering amplification, the intensity of scattered light is greatly improved, and further, the measurement distance, the spatial resolution and the measurement precision are greatly improved.

Specifically, referring to fig. 7, the measuring apparatus includes a laser emitting unit 201, a laser processing unit 202, a power adjusting unit 203, an optical coupling unit 204, a data processing unit 205, a first laser beam splitting unit 206, a second laser beam splitting unit 207, and a sweep processing unit 208. Referring to fig. 7, the first laser beam splitting unit 206 is connected to the laser emitting unit 201, the second laser beam splitting unit 207 is connected to the first laser beam splitting unit 206, and the sweep processing unit 208 is connected to the second laser beam splitting unit 207 and the sensing fiber.

Also, the first laser beam splitting unit 206 may split the laser light generated by the laser emitting unit 201 into a first laser signal and a second laser signal, and input the first laser signal to the laser processing unit 202. Further, the laser processing unit 202 may further convert the first laser signal into the pulse light signal, and input the pulse light signal into the power adjusting unit 203 to obtain a third pulse light signal with a power smaller than the stimulated brillouin threshold and a fourth pulse light with a power greater than the stimulated brillouin threshold, where the third pulse light signal is used as the probe light. Then, the third pulse optical signal is input into the sensing optical fiber to generate first scattered light.

The first laser beam splitting unit 206 is further configured to input the second laser signal into the second laser beam splitting unit 207.

The second laser beam splitting unit 207 is configured to receive the second laser signal input by the first laser beam splitting unit 206, split the second laser signal into a third laser signal and a fourth laser signal, input the third laser signal into the frequency sweep processing unit 208, and input the fourth laser signal into the data processing unit 205. The fourth laser signal is used as local oscillation light for coherent detection, and is used for coherent detection of scattered light to distinguish different scattered light, such as: rayleigh scattered light and brillouin scattered light.

The frequency sweep processing unit 208 is configured to receive the third laser signal input by the second laser beam splitting unit 207, perform frequency sweep processing on the third laser signal, input the probe light obtained after the frequency sweep processing into the sensing fiber, and then generate stimulated brillouin scattering amplification on the probe light and the fourth pulse light signal in the sensing fiber to obtain second scattered light. It should be noted that the scanning process refers to controlling the frequency of the third laser signal to sweep within a certain range, such as: the frequency of the third laser signal is different at different times, but always remains within a specified range.

The optical coupling unit 204 is further configured to receive the second scattered light obtained by stimulated brillouin scattering amplification of the probe light and the fourth pulse light signal in the sensing fiber, and the first scattered light generated by the third pulse light signal in the sensing fiber. And inputs the first scattered light and the second scattered light to the data processing unit 205.

The data processing unit 205 is further configured to perform coherent detection on the first scattered light and the second scattered light input by the optical coupling unit 204 according to the fourth laser signal input by the second laser beam splitting unit, obtain vibration information of the sensing fiber according to an intensity and/or a phase of an optical signal obtained after the coherent detection of the first scattered light, and obtain a temperature of the sensing fiber and deformation information of the sensing fiber according to a frequency shift of the optical signal obtained after the coherent detection of the second scattered light.

In some embodiments, when the measurement apparatus combines the DAS technology with the BOTDA technology in the DTSS to monitor the information of the sensing fiber, the measurement apparatus may also directly detect the scattered light to obtain the information of the sensing fiber without introducing local oscillator light to perform coherent detection on the scattered light. As shown in fig. 8, the measuring apparatus includes a laser emitting unit 201, a laser processing unit 202, a power adjusting unit 203, an optical coupling unit 204, a data processing unit 205, a first laser beam splitting unit 206, and a sweep processing unit 208. Referring to fig. 8, the first laser beam splitting unit 206 is connected to the laser emitting unit 201, and the sweep frequency processing unit 208 is connected to the first laser beam splitting unit 206 and the sensing fiber.

Also, the first laser beam splitting unit 206 may split the laser light generated by the laser emitting unit 201 into a first laser signal and a second laser signal, and input the first laser signal to the laser processing unit 202. Further, the laser processing unit 202 may further convert the first laser signal into the pulsed light signal, and input the pulsed light signal into the power adjusting unit 203 to obtain a third pulsed light signal and a fourth pulsed light signal, where the third pulsed light signal is probe light. Then, the third pulse optical signal is input into the sensing optical fiber to generate first scattered light.

The first laser beam splitting unit 206 may also input the second laser signal to the sweep frequency processing unit 208.

The frequency sweep processing unit 208 is configured to receive the second laser signal, perform frequency sweep processing on the second laser signal, input the probe light obtained after the frequency sweep processing into the sensing fiber, and then generate stimulated brillouin scattering amplification between the probe light and the fourth pulse light signal in the sensing fiber to obtain second scattered light.

The optical coupling unit 204 is further configured to receive the second scattered light obtained by stimulated brillouin scattering amplification of the probe light and the fourth pulse light signal in the sensing fiber, and the first scattered light generated by the third pulse light signal in the sensing fiber. And inputs the first scattered light and the second scattered light to the data processing unit 205.

The data processing unit 205 is further configured to obtain vibration information of the sensing fiber according to the first scattered light, and obtain temperature and deformation information of the sensing fiber according to the second scattered light.

In a specific implementation, the power adjusting unit 203 may be a Semiconductor Optical Amplifier (SOA) or an Optical Switch (OS). In some embodiments, the power conditioning unit 203 further comprises an Erbium-Doped Fiber Amplifier (EDFA).

In addition, the laser processing unit includes an acousto-optic Modulator (AOM). In some embodiments, the laser processing unit 203 further comprises an electro-optic Modulator (EOM). The sweep unit 208 may include an electro-optic modulator 2081 and a microwave generator 2082.

An embodiment of the present invention further provides a measurement apparatus, as shown in fig. 9, which measures information of a sensing optical fiber by using BOTDR techniques in DAS and DTSS. The device comprises the following components: the laser processing unit 202, the laser emitting unit 201, the power adjusting unit 203, the optical coupling unit 204, the photoelectric detection unit 2051, the data acquisition unit 2052, the system control unit 2053, the laser beam splitting unit 206, and the waveform generating unit 209.

The waveform generation unit 209 is connected to the laser processing unit 202 and the system control unit 2053. In a specific implementation, the waveform generating unit 209 is configured to generate a specified waveform according to the control of the system control unit 2053, so as to implement frequency modulation and pulse modulation on the pulse light signal generated by the laser processing unit 202.

First, the narrow linewidth laser generated by the laser emitting unit 201 is divided into two paths by the laser beam splitting unit 206, one path is used as the probe light of the device, and the other path is used as the local oscillator light for subsequent coherent detection.

Specifically, the probe light passes through the laser processing unit 202 to generate two pulse light signals with different frequency shifts (or frequency bands) at different times in one cycle. It should be noted that, if the pulsed light generated by the laser processing unit 202 is as shown in fig. 3, the apparatus may apply one pulsed light signal in one period to the Φ -OTDR technique to measure the vibration information of the sensing fiber, and may also apply another pulsed light signal to the BOTDR technique to measure the temperature and deformation information of the sensing fiber. If the pulsed light generated by the laser processing unit 202 is as shown in fig. 10, the apparatus may apply one pulsed light signal in one cycle to TGD-OFDR technique to measure the vibration information of the sensing fiber, and may also apply another pulsed light signal to BOTDR technique to measure the temperature and deformation information of the sensing fiber.

The laser processing unit 202 inputs the two pulse optical signals into the power adjusting unit 203, and the power adjusting unit 203 may respectively perform independent optimization and adjustment on the powers of the two pulse optical signals according to different functions of the two sets of pulse optical signals, such as being used for a Φ -OTDR technique (TGD-OFDR technique) or a BOTDR technique.

Subsequently, the detection light (two pulse light signals) whose power has been adjusted by the power adjustment unit 203 enters the sensing fiber through the optical coupling unit 204, and generates backward rayleigh scattered light and spontaneous brillouin scattered light at different positions of the sensing fiber, and then, the backward rayleigh scattered light and the spontaneous brillouin scattered light enter the photoelectric detection unit 2051 through the optical coupling unit 204.

The local oscillator light performs coherent detection on the scattered light input by the optical coupling unit 204 in the photoelectric detection unit 2051, and is converted into two electrical signals, and then the photoelectric detection unit 2051 inputs the two electrical signals into the data acquisition unit 2052. The data acquisition unit 2052 may convert the two electrical signals into digital signals and input the digital signals to the system control unit 2053. It should be noted that, the two pulse light signals input into the sensing fiber by the optical coupling unit 204 may generate rayleigh scattering and brillouin scattering, that is, the rayleigh scattering and brillouin scattering generated by the third pulse light signal and the rayleigh scattering and brillouin scattering generated by the fourth pulse light signal are input into the electrical detection unit 2051 by the optical coupling unit 204. However, since the rayleigh scattered light and the brillouin scattered light are completely shifted by 11GHz in frequency, the photodetection unit 204 can easily distinguish the rayleigh scattered light and the brillouin scattered light generated by the same pulse light signal, and since the two pulse light signals (i.e., the third pulse light signal and the fourth pulse light signal according to the embodiment of the present invention) have different frequency bands, the photodetection unit 2051 can also distinguish the rayleigh scattered light generated by the third pulse light signal and the brillouin scattered light generated by the fourth pulse light. In addition, the system control unit 2053 may also distinguish digital signals corresponding to the rayleigh scattering light and the brillouin scattering light, and demodulate vibration information, temperature, and deformation information of the sensing optical fiber by algorithm processing.

It should be noted that the system control unit 2053 needs the laser processing unit 202 to generate two sets of pulse light signals with different frequencies (or frequency shifts) at different times in one cycle; in addition, the power adjusting unit 203 is controlled to independently adjust the power of the two sets of pulse optical signals. For example, the DTSS and the DAS have different requirements on the peak power of the pulse light signal, if the pulse light signal is applied to the DAS to measure the vibration information of the sensing fiber, the power adjusting unit 203 may control the peak power of the pulse light signal to be below the stimulated brillouin threshold, and if the pulse light signal is applied to the BOTDR of the DTSS to measure the temperature/deformation information of the sensing fiber, the power adjusting unit 203 may control the peak power of the fourth pulse light signal to be below the stimulated brillouin threshold.

Therefore, the embodiment of the invention can realize the simultaneous measurement of the dynamic vibration, the static temperature and the deformation of the sensing optical fiber, and furthest realize the sharing of photoelectric devices, thereby greatly reducing the cost. Meanwhile, the laser processing unit 202 and the power adjusting unit 203 are utilized to realize independent optimization and adjustment of the two groups of pulse light signals.

An embodiment of the present invention further provides a measurement apparatus, as shown in fig. 11, which measures information of a sensing optical fiber by using BOTDA technology in DAS and DTSS. The device comprises the following components: the device comprises a laser emitting unit 201, a laser processing unit 202, a power adjusting unit 203, an optical coupling unit 204, a photoelectric detection unit 2051, a data acquisition unit 2052, a system control unit 2053, a laser beam splitting unit 206, a laser beam splitting unit 207, an electro-optical modulator 2081, a microwave generator 2082, a waveform generating unit 209 and a polarization control unit 210.

Among them, the electro-optical modulator 2081 can modulate the input continuous probe light into a swept probe light in the vicinity of the brillouin frequency shift.

The microwave generator 2082 can generate microwave signals to modulate the electro-optical modulator 2081, and the frequency sweeping function of the electro-optical modulator 2081 is realized.

The polarization control unit 210 may control the polarization state of the swept probe light. In a specific implementation, the Polarization control unit 210 may include a Polarization Polarizer (PS) or a Polarization Switch (PSW).

First, the laser emitting unit 201 generates a narrow-linewidth laser signal, and splits the laser signal into two paths by the laser beam splitting unit 206, where the first path of laser signal is used as the detection light of the DAS (i.e., the third pulse light signal according to the embodiment of the present invention) to generate backward rayleigh scattering light (i.e., the first scattering light according to the embodiment of the present invention) in the sensing fiber, and the first path of laser signal is also used as the pump light of the BOTDA (i.e., the fourth pulse light signal according to the embodiment of the present invention) to generate a stimulated brillouin effect with the detection sweep light in the sensing fiber. The second laser signal may be used as local oscillation light for coherent detection (i.e., the fourth laser signal according to the embodiment of the present invention) to perform coherent detection on the generated scattered light subsequently, and may also be used as continuous probe light for BOTDA (i.e., the third laser signal according to the embodiment of the present invention), and the subsequent pump light with the BOTDA generates stimulated brillouin scattering amplification in the sensing fiber to obtain second scattered light.

The first path of laser signals passes through the laser processing unit 202, and two pulse optical signals with different frequency shifts (or frequency bands) are generated at different times in one period (i.e., the first pulse optical signal and the second pulse optical signal according to the embodiment of the present invention). If the generated pulse light signals are as shown in fig. 3, one of the two pulse light signals is applied to the phi-OTDR to measure the vibration information of the sensing fiber, and the other pulse light signal is applied to the BOTDA to measure the temperature and deformation information of the sensing fiber; if the generated pulse light signals are as shown in fig. 10, one of the two pulse light signals is applied to TGD-OFDR to measure the vibration information of the sensing fiber, and the other pulse light signal is applied to BOTDA to measure the temperature and deformation information of the sensing fiber.

The laser processing unit 202 inputs the two pulse optical signals into the power adjusting unit 203, and performs independent optimal adjustment on the power of the pulse optical signals according to different functions of the two pulse optical signals. For example, the DTSS and the DAS have different requirements on peak powers of pulse light signals, if a pulse light signal (i.e., the third pulse light signal according to the embodiment of the present invention) is applied to the DAS for measuring vibration information of the sensing fiber, the power adjusting unit 203 may control the peak power of the pulse light signal to be below a stimulated brillouin threshold, and if a pulse light signal (i.e., the fourth pulse light signal according to the embodiment of the present invention) is applied to the BOTDA of the DTSS for measuring temperature/deformation information of the sensing fiber, the power adjusting unit 203 may control the peak power of the pulse light signal to be above the stimulated brillouin threshold. That is, the power of the third pulse light signal is less than the stimulated brillouin threshold, and the power of the fourth pulse light signal is greater than the stimulated brillouin threshold.

The power adjusting unit 203 may allow the adjusted pulse light signals (i.e., the third pulse light signal and the fourth pulse light signal according to the embodiment of the present invention) to enter the sensing fiber through the optical coupling unit 204, and the DAS probe light (i.e., the third pulse light signal according to the embodiment of the present invention) generates backward rayleigh scattering at different positions of the fiber.

In addition, the laser beam splitting unit 207 may split the second signal into two paths: continuous probe light of the BOTDA and local oscillator light of coherent detection. The continuous probe light of the BOTDA is input to the electro-optical modulator 2081, and is modulated into sweep light near the brillouin frequency shift by the electro-optical modulator 2081, that is, the probe light according to the embodiment of the present invention, and then passes through the polarization control unit 210, and the polarization control unit 210 controls the polarization state of the probe light, and inputs the probe light into the sensing optical fiber.

Then, the probe light is subjected to stimulated brillouin amplification of the BOTDA pump light in the sensing fiber, and second scattered light is obtained. The rayleigh scattered light generated by the third pulsed light signal in the sensing fiber and the second scattered light are input into the photoelectric detection unit 2051 through the optical coupling unit.

The local oscillator light performs coherent detection on the rayleigh scattered light and the second scattered light input by the optical coupling unit at the photoelectric detection unit 204, and converts the rayleigh scattered light and the second scattered light into two electrical signals, and then the photoelectric detection unit 204 inputs the two electrical signals into the data acquisition unit 2052. The data acquisition unit 2052 may convert the two electrical signals into digital signals and input the digital signals to the system control unit 2053. Since the rayleigh scattered light and the brillouin scattered light are completely shifted by 11GHz in frequency, the photodetection unit 204 can also distinguish between the rayleigh scattered light generated by the third pulse light signal and the scattered light obtained by the stimulated brillouin amplification of the fourth pulse light. In addition, the system control unit 2053 may also distinguish digital signals corresponding to the rayleigh scattering light and the brillouin scattering light, and demodulate vibration information, temperature, and deformation information of the sensing optical fiber by algorithm processing.

It should be noted that the system control unit 2053 needs the laser processing unit 202 to generate two sets of pulse light signals with different frequencies (or frequency shifts) at different times in one cycle; in addition, the power adjusting unit 203 is controlled to independently adjust the power of the two sets of pulse optical signals. For example, the DTSS and the DAS have different requirements on the peak power of the pulsed light signal, if the pulsed light signal is applied to the DAS to measure the vibration information of the sensing fiber, the power adjusting unit 203 may control the peak power of the pulsed light signal to be below the stimulated brillouin threshold, and if the pulsed light signal is applied to the BOTDA of the DTSS to measure the temperature/deformation information of the sensing fiber, the power adjusting unit 203 may control the peak power of the pulsed light signal to be above the stimulated brillouin threshold.

The measurement device shown in fig. 11 combines the technology of Φ -OTDR in DAS and BOTDA in DTSS to realize simultaneous measurement of dynamic vibration and static temperature/strain. In addition, the device realizes the maximum sharing of the photoelectric device, and the cost is greatly reduced. The power regulating unit can be used for realizing independent optimal regulation of pulse power. Due to the adoption of the BOTDA technology in the DTSS, the measurement distance, the spatial resolution and the measurement precision are greatly improved.

An embodiment of the present invention further provides a measurement method, which may be applied to the measurement apparatus according to the embodiment of the present invention, as shown in fig. 12, where the method includes the following steps:

1201. the measuring device generates a laser signal and converts the laser signal into a periodically occurring pulsed light signal. The pulse light signals comprise first pulse light signals and second pulse light signals, the frequency bands of the first pulse light signals and the frequency bands of the second pulse light signals are different, and the time of occurrence of the first pulse light signals and the time of occurrence of the second pulse light signals are different.

The first pulsed light signal and the second pulsed light signal generated by the measuring device may be the pulsed light signals shown in fig. 3, or may be the pulsed light signals shown in fig. 10.

If the pulsed light generated by the measuring device is as shown in fig. 3, the device can apply a pulsed light signal in one period to the phi-OTDR technology to measure the vibration information of the sensing fiber, and can also apply another pulsed light signal to the BOTDR technology to measure the temperature and deformation information of the sensing fiber. If the pulsed light generated by the measuring device is as shown in fig. 9, the device can apply one pulsed light signal in one period to the TGD-OFDR technology to measure the vibration information of the sensing fiber, and can also apply another pulsed light signal to the BOTDR technology to measure the temperature and deformation information of the sensing fiber.

Or, if the pulsed light signals generated by the measuring device are as shown in fig. 10, one of the two pulsed light signals is applied to the Φ -OTDR to measure the vibration information of the sensing fiber, and the other pulsed light signal is applied to the BOTDA to measure the temperature and deformation information of the sensing fiber; if the pulse light signals generated by the measuring device are as shown in fig. 9, one of the two pulse light signals is applied to TGD-OFDR to measure the vibration information of the sensing fiber, and the other pulse light signal is applied to BOTDA to measure the temperature and deformation information of the sensing fiber.

1202. The measuring device is used for carrying out power adjustment on the first pulse optical signal to obtain a third pulse optical signal, carrying out power adjustment on the second pulse optical signal to obtain a fourth pulse optical signal, and inputting the third pulse optical signal and the fourth pulse optical signal into the sensing optical fiber. The power of the third pulse light is smaller than the stimulated Brillouin threshold value, and the power of the fourth pulse light is larger than the stimulated Brillouin threshold value, or the power of the third pulse light and the power of the fourth pulse light are both smaller than the stimulated Brillouin threshold value.

In specific implementation, the first pulse optical signal is applied to the DAS to measure the vibration information of the sensing optical fiber, and the second pulse optical signal is applied to the DTSS to measure the temperature and deformation information of the sensing optical fiber.

For example, the DTSS and the DAS have different requirements on the peak power of the pulsed light signal, and if the pulsed light signal is applied to the DAS for measuring the vibration information of the sensing fiber, the measurement device may control the peak power of the pulsed light signal to be below the stimulated brillouin threshold, that is, the power of the third pulsed light signal is smaller than the stimulated brillouin threshold; if the pulsed light signal is applied to the BOTDR of the DTSS to measure the temperature/deformation information of the sensing fiber, the measuring device may control the peak power of the pulsed light signal to be below the stimulated brillouin threshold, i.e., the power of the fourth pulsed light signal is smaller than the stimulated brillouin threshold. If the pulsed light signal is applied to the BOTDA of the DTSS to measure the temperature/deformation information of the sensing fiber, the measuring device may control the peak power of the pulsed light signal to be above the stimulated brillouin threshold, i.e., the power of the fourth pulsed light signal is greater than the stimulated brillouin threshold.

1203. The measuring device receives first scattered light generated by the third pulse light signal in the sensing optical fiber and second scattered light generated by the fourth pulse light signal in the sensing optical fiber, obtains vibration information of the sensing optical fiber according to the first scattered light, and obtains temperature and deformation information of the sensing optical fiber according to the second scattered light.

In a specific implementation, the measuring device may convert the first scattered light into a first electrical signal and convert the second scattered light into a second electrical signal. Further, the first electrical signal is converted into a first digital signal, and the second electrical signal is converted into a second digital signal. Finally, the first digital signal can be demodulated to obtain vibration information of the sensing optical fiber, and the second digital signal can be demodulated to obtain temperature and deformation information of the sensing optical fiber.

In some embodiments, the measurement device can perform coherent detection on the scattered light when the DAS is used for measuring the vibration information of the sensing optical fiber, so that a more accurate measurement result can be obtained. Specifically, after the measuring device generates the laser signal, the generated laser signal is divided into two paths: a first laser signal and a second laser signal. The first laser signal is used as detection light for measuring information of the sensing optical fiber. The measuring device can convert the first laser signal into two periodically-occurring pulse light signals, then the two pulse light signals are subjected to power adjustment, and a third pulse light signal and a fourth pulse light signal obtained after the power adjustment are input into the sensing light. In the embodiment of the present invention, the measuring apparatus may obtain vibration information of the sensing optical fiber according to the rayleigh scattering (i.e., the first scattered light) generated by the third pulsed light signal, and obtain temperature and deformation information of the sensing optical fiber according to the brillouin (i.e., the second scattered light) generated by the fourth pulsed light signal.

In addition, the second laser signal is used as a local oscillator light for coherent detection to perform coherent detection on the scattered light, specifically: after receiving first scattered light generated by the third pulsed light signal in the sensing optical fiber and second scattered light generated by the fourth pulsed light signal in the sensing optical fiber, a measuring device performs coherent detection on the first scattered light and the second scattered light according to the second laser signal, obtains vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtains the temperature of the sensing optical fiber and the deformation information of the sensing optical fiber according to the intensity and/or frequency shift of an optical signal obtained after the coherent detection of the second scattered light.

In some embodiments, the measurement device may further use a BOTDA to measure information of the sensing optical fiber, and the BOTDA measures temperature and deformation information of the sensing optical fiber using scattered light obtained by the stimulated brillouin amplification, and may effectively improve measurement accuracy due to a large intensity of the scattered light obtained by the stimulated brillouin amplification. In particular, the measuring device divides the generated laser signal into a first laser signal and a second laser signal. The first laser signal is used as DAS detection light for measuring vibration information of the sensing optical fiber. The measuring device can convert the first laser signal into two periodically-occurring pulse light signals, and then power adjustment is carried out on the two pulse light signals, wherein the power of the third pulse light signal is smaller than the stimulated Brillouin threshold value, and the power of the fourth pulse light signal is larger than the stimulated Brillouin threshold value. And further inputting a third pulse light signal and a fourth pulse light signal obtained after power adjustment into the sensing light, wherein the third pulse light signal can generate Rayleigh scattering and Brillouin scattering in the sensing light. In the embodiment of the present invention, the measurement apparatus may obtain the vibration information of the sensing optical fiber according to rayleigh scattering (i.e. the first scattered light) generated by the third pulsed light signal.

The measurement device may also split the second laser signal into a third laser signal and a fourth laser signal. Further, frequency sweeping processing is performed on the third laser signal, probe light (probe light for measuring the temperature and deformation information of the sensing fiber by applying DTSS) obtained after the frequency sweeping processing is input into the sensing fiber, and then the probe light and a fourth pulse light signal input by the measuring device are subjected to stimulated brillouin scattering amplification in the sensing fiber to obtain second scattered light.

Furthermore, the measuring device may further perform coherent detection on the first scattered light and the second scattered light according to the fourth laser signal, obtain vibration information of the sensing optical fiber according to the intensity and/or phase of an optical signal obtained after the coherent detection of the first scattered light, and obtain the temperature of the sensing optical fiber and deformation information of the sensing optical fiber according to the frequency shift of the optical signal obtained after the coherent detection of the second scattered light.

In some embodiments, the measuring device may further adjust subsequent measurement behaviors according to a previous measurement result, for example, the measuring device may update the frequency band and the pulse width of the first pulsed light signal and the power of the third pulsed light signal according to the obtained vibration information of the sensing optical fiber; and according to the obtained temperature and deformation information of the sensing optical fiber, the frequency band and the pulse width of the second pulse optical signal and the power of the fourth pulse optical signal. Specifically, the obtained vibration information may be analyzed, and if the accuracy of the vibration information is low, the current pulse width and frequency band of the first pulse light, and the current power of the third pulse light signal may be updated. The obtained deformation information (or temperature) can also be analyzed, and if the accuracy of the vibration information (or temperature) is low, the current pulse width and frequency band of the second pulse light and the current power of the fourth pulse light signal can be updated. It should be noted that, in the embodiment of the present invention, the accuracy of the information (e.g., vibration information, deformation information, and temperature of the optical fiber) refers to a proximity degree to an actual external environment of the sensing optical fiber, and the more the information can reflect the actual external environment of the sensing optical fiber, the higher the accuracy of the information is.

Further, the laser signal can be modulated into the pulse light signal with the specific frequency band and the specific pulse width according to the frequency band of the updated first pulse light signal, the pulse width of the updated second pulse light signal and the frequency band of the updated second pulse light signal, and then the vibration information with high accuracy can be obtained according to the rayleigh scattering light generated by the pulse light signal. In addition, the power of the pulse light signals can be adjusted according to the updated power of the third pulse light signals and the updated power of the fourth pulse light signals.

Of course, if the accuracy of the vibration information is determined to be high after analyzing the vibration information, the measurement device may not update the current configuration, such as: the current pulse width, the frequency range and the current power of the third pulse light signal of the first pulse light are not updated. Similarly, if the accuracy of the deformation information (or temperature) is determined to be high after the deformation information (or temperature) is analyzed, the current configuration may not be updated, for example: the pulse width and the frequency range of the current second pulse light and the power of the current fourth pulse light signal are not updated.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.