1. A high resolution two dimensional fast steering mirror dynamic angle measuring device, said measuring device comprising: the device comprises a laser (1), a spatial filter (2), a reference reflector (3), an electric three-dimensional displacement table (4), a converging lens (5) and a high-speed CCD camera (6);

the laser (1) adopts a TEM₀₀Outputting a laser beam with a circular light spot as a test target;

the spatial filter (2) comprises: a microscope objective (2-1), a small aperture diaphragm (2-2), a collimating objective (2-3) and an iris diaphragm (2-4); the device is used for converging an input laser beam, meanwhile, spatial filtering and shaping are realized through the small-hole diaphragm (2-2) at the position where a light spot converges, the filtered laser beam forms a collimated emergent beam through the collimating objective lens (2-3), and the collimated emergent beam is emitted to the two-dimensional rapid control reflector to be detected;

the reference reflector (3) is a plane reflector, is arranged on the electric three-dimensional displacement table (4), receives a reflected beam passing through the two-dimensional rapid control reflector to be detected, and outputs a laser beam after being reflected for multiple times between the reference reflector and the two-dimensional rapid control reflector to be detected;

the electric three-dimensional displacement table (4) is used for three-dimensionally moving along an optical axis direction defined as a Z axis and an X axis and a Y axis vertical to the Z axis to control the folding times of light rays;

the converging lens (5) is connected with the high-speed CCD camera (6) through a standard interface, and receives the laser beams passing through the reference reflector (3).

2. The high resolution two dimensional fast steering mirror dynamic angle measuring device of claim 1, wherein said measuring device further comprises: a computer acquisition processing system (7);

and the computer acquisition processing system (7) is respectively connected with the high-speed CCD camera (6) and the external controller.

3. The dynamic angle measuring device for the high-resolution two-dimensional fast control reflecting mirror according to claim 2, wherein the external controller is connected to the measured two-dimensional fast control reflecting mirror for controlling the movement of the measured two-dimensional fast control reflecting mirror.

4. The high-resolution two-dimensional fast control mirror dynamic angle measuring device according to claim 1, characterized in that the laser (1) is co-axial with the spatial filter (2), the reference mirror (3), the condenser lens (5) and the high-speed CCD camera (6).

5. The high resolution two-dimensional fast steering mirror dynamic angle measurement device according to claim 1, characterized in that said laser (1) employs TEM₀₀And in the mode, a circular light spot is output, so that the problem of high cross line target brightness loss in the measurement of an auto-collimation method is solved.

6. The high-resolution two-dimensional fast-control mirror dynamic angle measuring device according to claim 1, characterized in that the high-speed CCD camera (6) has a windowing frame frequency of more than 3000Hz for high-frequency dynamic angle measurement with a control bandwidth of 3000 Hz.

7. The dynamic angle measuring device of the high resolution two-dimensional fast control reflector according to claim 1, wherein the dynamic angle measuring device of the high resolution two-dimensional fast control reflector operates in a manner that a laser (1) generates a circular light spot as a measurement target, the circular light spot enters the measured two-dimensional fast control reflector after being shaped by a spatial filter (2), and the circular light spot enters a reference reflector (3) after being reflected by the measured reflector; when the reflecting mirror surface of the two-dimensional rapid control reflecting mirror to be detected inclines by a tiny angle alpha, the light beam inclines by an angle of 2 alpha after every reflection; if the light is reflected between the two-dimensional fast control reflector to be measured and the reference reflector (3) for n times, the emergent light is inclined by 2ⁿα, thus improving the resolution of the two-dimensional fast mirror angle measurement by 2ⁿThe reflected light beam is received by the high-speed CCD camera (6) through the light source (5); so that the high-speed CCD camera (6) can obtain the initial position D (x) of the laser spot₀,y₀,t₀)；

When the external controller controls the two-dimensional fast control reflector to move, the position of a light spot image on the CCD target surface of the high-speed CCD camera (6) is changed into D (x, y, t, n), and therefore, D (x) is passed₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional fast control reflector to be measured can be obtained.

8. High resolution two dimensional fast control as claimed in claim 7Mirror dynamic angle measuring device, characterized in that the pass D (x)₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional rapid control reflector to be detected can be obtained, and the method specifically comprises the following steps:

the deflection angle α of the fast control mirror is obtained by:

in the above formula, f is the focal length of the objective lens.

9. The dynamic angle measuring device of high resolution two-dimensional fast steering mirror according to claim 1, characterized in that the laser (1) selects a semiconductor laser with wavelength 527nm, output power: 20mW, divergence angle: 1.2mrad, stability < 0.12%.

10. The dynamic angle measuring device of high resolution two-dimensional fast control mirror according to claim 1, characterized in that the size of the aperture stop (2-2) is calculated and selected by the following formula:

in the formula: d_optThe diameter of the aperture diaphragm, F the focal length of the microscope objective, lambda the wavelength and a the radius of the laser spot.

Background

The two-dimensional fast control reflector (FSM) is widely applied to the fields of photoelectric tracking systems, laser communication, adaptive optics and the like by virtue of high system integration level, small rotational inertia, high dynamic performance and the like, and the resolution and the measurement error of a dynamic angle directly determine the indication precision of a photoelectric system.

Currently, the commonly used FSM controls an angular range of about 1.0 "to about 15 °, a control bandwidth of about 100Hz to about 3000Hz, and an angular resolution of about 0.2" to about 0.02 ". However, as the process is improved, the angular range and angular resolution are gradually improved, and the angular resolution of some FSMs has reached 0.004 "or even higher.

At present, an auto-collimation method is mainly adopted for measuring the dynamic angle of a two-dimensional fast control reflector. The two-dimensional small angle measurement technology based on the photoelectric auto-collimation method is introduced in the master academic paper of Suli of the university of Sigan science and the master academic paper of He Bei industry university of Huohui of 2009. The method generally adopts an autocollimator to emit an optical cross target, the cross center of the target changes after the target is reflected by an FSM, and the angle change of the FSM can be calculated by measuring the line quantity change of the cross center on a photoelectric receiver.

The method has the advantages of simple measurement principle and simple and convenient operation. But has the following disadvantages:

(1) at present, the resolution of the photoelectric auto-collimation method can only reach 0.01 "(the highest energy in foreign countries reaches 0.005"), and the measurement requirements of the current FSM angular resolution of 0.004 "and higher resolution are difficult to meet.

(2) At present, photoelectric autocollimators produced at home and abroad are mainly used for static test, the response frequency is not high, and the requirements of high-speed measurement of 3000Hz and the like cannot be met.

(3) When the autocollimator is used for measurement, the brightness loss is large, and the autocollimator image is dark, so that the measurement precision is influenced to a certain extent.

In order to solve the above problems, and with the continuous improvement of the performance of the two-dimensional fast control reflector, it is urgently needed to develop a new dynamic angle measuring device for the high-resolution two-dimensional fast control reflector.

Disclosure of Invention

Technical problem to be solved

The technical problem to be solved by the invention is as follows: aiming at the defects of the prior art, how to provide a high-resolution two-dimensional rapid control reflector dynamic angle measuring device.

(II) technical scheme

In order to solve the above technical problem, the present invention provides a dynamic angle measuring device for a high resolution two-dimensional fast control reflector, comprising: the device comprises a laser 1, a spatial filter 2, a reference reflector 3, an electric three-dimensional displacement table 4, a converging lens 5 and a high-speed CCD camera 6;

the laser 1 adopts a TEM₀₀Outputting a laser beam with a circular light spot as a test target;

the spatial filter 2 includes: 2-1 parts of microscope objective, 2-2 parts of aperture diaphragm, 2-3 parts of collimating objective and 2-4 parts of variable diaphragm; the device is used for converging an input laser beam, realizing spatial filtering and shaping through the small-hole diaphragm 2-2 at the position where a light spot converges, forming a collimated emergent beam through the collimating objective lens 2-3 after filtering, and emitting the collimated emergent beam to a two-dimensional rapid control reflector to be measured;

the reference reflector 3 is a plane reflector, is arranged on the electric three-dimensional displacement table 4, receives a reflected beam passing through the two-dimensional rapid control reflector to be detected, and outputs a laser beam after multiple reflections with the two-dimensional rapid control reflector to be detected;

the electric three-dimensional displacement table 4 is used for three-dimensionally moving along an optical axis direction defined as a Z axis and an X axis and a Y axis vertical to the Z axis and controlling the folding times of light rays;

the converging lens 5 is connected with the high-speed CCD camera 6 through a standard interface, and receives the laser beam passing through the reference reflector 3.

Wherein the measuring device further comprises: a computer acquisition processing system 7;

and the computer acquisition processing system 7 is respectively connected with the high-speed CCD camera 6 and an external controller.

The external controller is connected with the two-dimensional rapid control reflector to be detected and is used for controlling the movement of the two-dimensional rapid control reflector to be detected.

The laser 1, the spatial filter 2, the reference reflector 3, the converging lens 5 and the high-speed CCD camera 6 share an optical axis.

Wherein the laser 1 adopts TEM₀₀And in the mode, a circular light spot is output, so that the problem of high cross line target brightness loss in the measurement of an auto-collimation method is solved.

The windowing frame frequency of the high-speed CCD camera 6 is greater than 3000Hz, and the high-speed CCD camera is used for realizing high-frequency dynamic angle measurement under the control bandwidth of 3000 Hz.

The high-resolution two-dimensional rapid control reflector dynamic angle measuring device works in a mode that a laser 1 generates a circular light spot as a measuring target, the circular light spot is shaped by a spatial filter 2 and then enters a measured two-dimensional rapid control reflector, and the circular light spot is reflected by the measured reflector and then enters a reference reflector 3; when the reflecting mirror surface of the two-dimensional rapid control reflecting mirror to be detected inclines by a tiny angle alpha, the light beam inclines by an angle of 2 alpha after every reflection; if the light is reflected between the two-dimensional fast control reflector to be measured and the reference reflector 3 for n times, the emergent light is inclined by 2ⁿα, thus enabling resolution of two-dimensional fast mirror angle measurementsThe rate is improved by 2ⁿThe reflected light beam is received by a high-speed CCD camera 6 through a 5; so that the high-speed CCD camera 6 can obtain the initial position D (x) of the laser spot₀,y₀,t₀)；

When the external controller controls the two-dimensional fast control reflector to move, the position of the light spot image on the CCD target surface of the high-speed CCD camera 6 is changed to D (x, y, t, n), so that D (x) is passed₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional fast control reflector to be measured can be obtained.

Wherein the passage D (x)₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional rapid control reflector to be detected can be obtained, and the method specifically comprises the following steps:

the deflection angle α of the fast control mirror is obtained by:

in the above formula, f is the focal length of the objective lens.

Wherein, the laser 1 selects the semiconductor laser with the wavelength of 527nm, and the output power is as follows: 20mW, divergence angle: 1.2mrad, stability < 0.12%.

Wherein, the size of the small-hole diaphragm 2-2 is calculated and selected by the following formula:

in the formula: d_optThe diameter of the aperture diaphragm, F the focal length of the microscope objective, lambda the wavelength and a the radius of the laser spot.

(III) advantageous effects

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention adopts a mode of turning a reference reflector and an FSM light path to increase the FSM deflection angle to 2ⁿAnd the measurement with higher resolution can be realized. When the tilt angle of FSMThe resolution is 0.02", and the minimum deflection angle of the light beam is about 0.001" after the light is reflected four times, which is obviously improved compared with the resolution of the autocollimation method.

(2) The invention adopts the precise program-controlled electric three-dimensional displacement table to control the axial movement of the reference reflector, and can precisely control the turning times of the light.

(3) The invention adopts the spatial filter to perform spatial shaping on laser spots, and can realize high-frequency dynamic angle measurement under the control bandwidth of 3000Hz by combining with the high-speed CCD camera.

(4) The laser spot in the TEM00 mode is used as the measurement target, so that the problem of high brightness loss of the reticle target during measurement of the autocollimator can be solved.

Drawings

FIG. 1 is a schematic diagram of the dynamic angle measuring device of the high-resolution two-dimensional fast control reflector of the present invention.

Fig. 2 is a schematic diagram of a spatial filter composition.

Detailed Description

In order to make the objects, contents, and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be made in conjunction with the accompanying drawings and examples.

In order to solve the above technical problem, the present invention provides a dynamic angle measuring device for a high-resolution two-dimensional fast-control reflector, as shown in fig. 1 and 2, the measuring device comprises: the device comprises a laser 1, a spatial filter 2, a reference reflector 3, an electric three-dimensional displacement table 4, a converging lens 5 and a high-speed CCD camera 6;

the laser 1 adopts a TEM₀₀Outputting a laser beam with a circular light spot as a test target;

the spatial filter 2 includes: 2-1 parts of microscope objective, 2-2 parts of aperture diaphragm, 2-3 parts of collimating objective and 2-4 parts of variable diaphragm; the device is used for converging an input laser beam, realizing spatial filtering and shaping through the small-hole diaphragm 2-2 at the position where a light spot converges, forming a collimated emergent beam through the collimating objective lens 2-3 after filtering, and emitting the collimated emergent beam to a two-dimensional rapid control reflector to be measured;

the reference reflector 3 is a plane reflector, is arranged on the electric three-dimensional displacement table 4, receives a reflected beam passing through the two-dimensional rapid control reflector to be detected, and outputs a laser beam after multiple reflections with the two-dimensional rapid control reflector to be detected;

the electric three-dimensional displacement table 4 is used for three-dimensionally moving along an optical axis direction defined as a Z axis and an X axis and a Y axis vertical to the Z axis, and accurately controlling the folding times of light rays;

the converging lens 5 is connected with the high-speed CCD camera 6 through a standard interface, and receives the laser beam passing through the reference reflector 3.

Wherein the measuring device further comprises: a computer acquisition processing system 7;

and the computer acquisition processing system 7 is respectively connected with the high-speed CCD camera 6 and an external controller.

The external controller is connected with the two-dimensional rapid control reflector to be detected and is used for controlling the movement of the two-dimensional rapid control reflector to be detected.

The laser 1, the spatial filter 2, the reference reflector 3, the converging lens 5 and the high-speed CCD camera 6 share an optical axis.

Wherein the laser 1 adopts TEM₀₀And in the mode, a circular light spot is output, so that the problem of high cross line target brightness loss in the measurement of an auto-collimation method is solved.

The windowing frame frequency of the high-speed CCD camera 6 is greater than 3000Hz, and the high-speed CCD camera is used for realizing high-frequency dynamic angle measurement under the control bandwidth of 3000 Hz.

The high-resolution two-dimensional rapid control reflector dynamic angle measuring device works in a mode that a laser 1 generates a circular light spot as a measuring target, the circular light spot is shaped by a spatial filter 2 and then enters a measured two-dimensional rapid control reflector, and the circular light spot is reflected by the measured reflector and then enters a reference reflector 3; when the reflecting mirror surface of the two-dimensional rapid control reflecting mirror to be detected inclines by a tiny angle alpha, the light beam inclines by an angle of 2 alpha after every reflection; if the light is reflected between the two-dimensional fast control reflector to be measured and the reference reflector 3 for n times, thenThe emergent ray is inclined 2ⁿα, thus improving the resolution of the two-dimensional fast mirror angle measurement by 2ⁿThe reflected light beam is received by a high-speed CCD camera 6 through a 5; so that the high-speed CCD camera 6 can obtain the initial position D (x) of the laser spot₀,y₀,t₀)；

When the external controller controls the two-dimensional fast control reflector to move, the position of the light spot image on the CCD target surface of the high-speed CCD camera 6 is changed to D (x, y, t, n), so that D (x) is passed₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional fast control reflector to be measured can be obtained.

Wherein the passage D (x)₀,y₀,t₀) And D (x, y, t, n), the deflection angle alpha of the two-dimensional rapid control reflector to be detected can be obtained, and the method specifically comprises the following steps:

the deflection angle α of the fast control mirror is obtained by:

in the above formula, f is the focal length of the objective lens.

Wherein, the laser 1 selects the semiconductor laser with the wavelength of 527nm, and the output power is as follows: 20mW, divergence angle: 1.2mrad, stability < 0.12%.

Wherein, the size of the small-hole diaphragm 2-2 is calculated and selected by the following formula:

in the formula: d_optThe diameter of the aperture diaphragm, F the focal length of the microscope objective, lambda the wavelength and a the radius of the laser spot.

Example 1

As shown in fig. 1, the high-resolution two-dimensional fast control mirror dynamic angle measuring apparatus in the present embodiment includes: the device comprises a laser 1, a spatial filter 2, a reference reflector 3, an electric three-dimensional displacement table 4, a converging lens 5, a high-speed CCD camera 6 and a computer acquisition processing system 7.

The laser 1 adopts a TEM00 mode, outputs a circular light spot as a test target, and has an optical axis which is coaxial with the spatial filter 2, the reference reflector 3, the converging lens 5 and the high-speed CCD camera 6. In the preferred embodiment, the semiconductor laser with a wavelength of 527nm is selected in consideration of the aspects of working volume, efficiency, power loss, stability and the like, and the output power is as follows: 20mW, divergence angle: 1.2mrad, stability < 0.12%.

As shown in fig. 2, the spatial filter 2 includes: 2-1 of microobjective, 2-2 of aperture diaphragm, 2-3 of collimating objective and 2-4 of variable diaphragm; the function of the device is to converge the input laser beam, realize spatial filtering through the aperture diaphragm at the spot convergence position, and form a collimated emergent beam through the collimating objective lens after filtering. In the preferred embodiment, the size of the aperture stop can be calculated and selected by the following formula:

in the formula: d_optThe diameter of the aperture diaphragm, F the focal length of the microscope objective, lambda the wavelength and a the radius of the laser spot.

The reference reflector 3 is a plane reflector, is arranged on the electric three-dimensional displacement table 4, receives a reflected beam passing through the FSM, and outputs a laser beam after multiple reflections with the FSM; in the preferred embodiment, the material of the plane mirror can be quartz or microcrystalline glass.

The electric three-dimensional displacement table 4 can move three-dimensionally along the Z axis in the optical axis direction and the X axis and the Y axis vertical to the Z axis, and the folding times of the light rays are accurately controlled.

The converging lens 5 is connected with the high-speed CCD camera 6 through a standard interface, and receives the laser beam passing through the reference reflector. In the preferred embodiment, the model of the high-speed camera is an EoSens 4CXP model, the resolution is 2336 × 1728, and the windowing frame rate is as follows: 3020fps, pixel size: 7 μm, can meet the requirement of high-speed measurement.

The high-resolution two-dimensional rapid control reflector dynamic angle measuring device is characterized in that: the working mode is that the laser 1 generates a circular light spot as a measurement target, the circular light spot is shaped by the spatial filter 2 and then enters the two-dimensional rapid control reflector to be measured, and the circular light spot is reflected by the reflector to be measured and then enters the reference reflector 3. When the reflecting mirror surface to be measured is inclined by a tiny angle alpha, the light beam is inclined by an angle of 2 alpha after every reflection. If the light is reflected n times, the emergent light is inclined by 2ⁿα, thus improving the resolution of the two-dimensional fast mirror angle measurement by 2ⁿThe reflected beam is received by 5 and by 6 a high-speed CCD camera. The high-speed CCD camera 6 can obtain the initial position D (x) of the laser spot₀,y₀,t₀). When the controller controls the fast reflector to move, the position of the light spot image on the CCD target surface is changed into D (x, y, t), and the deflection angle alpha of the fast reflector can be obtained through the following formula:

in the above formula, f is the focal length of the objective lens.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.