1. A wavelength division multiplexer, characterized by: the Mach-Zehnder interferometer comprises at least two polarization control structures arranged on a silicon substrate and at least one polarization-independent Mach-Zehnder interferometer;

a single said polarization control structure comprises two input ports and one output port; the single Mach-Zehnder interferometer comprises two input ports and an optical signal output port, and the optical signal output port is used for outputting a combined wave optical signal; the output port of the polarization control structure is connected with the input port of the Mach-Zehnder interferometer;

the single polarization control structure receives two paths of linearly polarized light in the incident linearly polarized light, synthesizes a path of secondary wave-combining optical signal with two linear polarization states which are vertical to each other, outputs the secondary wave-combining optical signal and inputs the secondary wave-combining optical signal through one input port of the Mach-Zehnder interferometer; and the at least one polarization-independent Mach-Zehnder interferometer receives the secondary wave-combined optical signals output by the at least two polarization control structures, and combines the secondary wave-combined optical signals into a path of wave-combined optical signal with two linear polarization states which are vertical to each other to output.

2. A wavelength division multiplexer according to claim 1, wherein: the wavelength division multiplexer includes n polarization control structures and n-1 polarization independent Mach-Zehnder interferometers, where n is an integer greater than or equal to 2.

3. A wavelength division multiplexer according to claim 1, wherein: the polarization control structure is an integrated polarization rotator-combiner.

4. A wavelength division multiplexer according to claim 3, wherein: the integrated polarization rotation-beam combiner comprises a through waveguide, a cross waveguide, a through port and a cross port which are respectively connected with the through waveguide and the cross waveguide, and a mode conversion structure connected with the through waveguide; the through waveguide and the cross waveguide form a mode multiplexing structure; the through port and the cross port both comprise a wedge-shaped structure of a strip waveguide-ridge waveguide; the mode conversion structure is a double-layer wedge-shaped mode conversion structure.

5. A wavelength division multiplexer according to claim 1, wherein: the polarization control structure comprises a polarization rotator and a polarization beam combiner.

6. A wavelength division multiplexer according to claim 5, wherein: the polarization beam combiner comprises three same mode conversion couplers, and each single mode conversion coupler comprises a single-mode access waveguide and a multi-mode bus waveguide;

the first mode conversion coupler and the second mode conversion coupler of the three mode conversion couplers are arranged in parallel, the multimode bus waveguide of the third mode conversion coupler is connected with the multimode bus waveguide of the first mode conversion coupler, and the single-mode access waveguide is connected with the output end of the single-mode access waveguide of the second mode conversion coupler.

7. A wavelength division multiplexer according to any one of claims 1 to 6, wherein: the single Mach-Zehnder interferometer comprises a 2 multiplied by 2 input 3dB coupler, two phase shift arms and a 2 multiplied by 2 output 3dB coupler which are sequentially connected; at least one of the two phase shifting arms is a phase-variable shifting arm;

the input 3dB coupler and the output 3dB coupler are both polarization-independent couplers, and the phase shift arms are both provided with polarization rotators.

8. A wavelength division multiplexer according to claim 7, wherein: the mach-zehnder interferometer further includes a monitor detector optically connected to one output port of the output 3dB coupler.

9. A silicon optical integrated chip is characterized in that: comprising a wavelength division multiplexer according to any one of claims 1-8.

10. The silicon photonic integrated chip of claim 9, wherein: the silicon optical integrated chip also comprises an optical modulator; after the multiple paths of incident light signals are modulated by the optical modulator, the multiple paths of modulated light signals are output; the multi-path modulation optical signals are respectively input through an input port of a polarization control structure of the wavelength division multiplexer, and output a path of wave combination optical signal after passing through the polarization control structure and the Mach-Zehnder interferometer.

Background

The wavelength division multiplexing technology is an effective means for increasing the optical communication capacity, and the key devices are a wavelength division multiplexing device (MUX) and a wavelength division demultiplexing Device (DEMUX). The main structures of the planar waveguide type wavelength division multiplexer include an array waveguide grating, an etched diffraction grating, a cascaded Mach-Zehnder interferometer (MZI), and the like.

The silicon optical chip is a key device for realizing optical interconnection, and can effectively reduce the cost of the module in optical communication. As shown in fig. 1, a wavelength division multiplexer of a cascaded mach-zehnder interferometer structure in silicon light, taking four-channel wavelength division multiplexing as an example, includes 3 mach-zehnder interferometers 10 ' connected in parallel and cascaded, and a single mach-zehnder interferometer 10 ' includes two 2 × 23 dB couplers 11 ', two connecting arms 12 ' and a monitor detector 13 ', where one connecting arm is a phase-shiftable arm (shown by a dotted line in the figure). When in use, the adjustable phase shift arms of the cascaded Mach-Zehnder interferometers 10 'need to be adjusted by combining the monitoring detector 13', the adjusting process is inconvenient, and the power consumption is large. The 3dB couplers 11 ' have a limited optical bandwidth, and the optical path of the wavelength division multiplexer having the plurality of cascaded mach-zehnder interferometers 10 ' has the plurality of 3dB couplers 11 ' therein, which significantly reduces the performance of the wavelength division multiplexer.

Disclosure of Invention

The application aims to provide a wavelength division multiplexer and a silicon optical integrated chip, the number of phase shift arms is reduced, and the wavelength division multiplexer and the silicon optical integrated chip have the advantages of low power consumption, large optical bandwidth, easiness in adjustment, good stability and the like.

In order to achieve one of the above objects, the present application provides a wavelength division multiplexer comprising at least two polarization control structures and at least one polarization independent mach-zehnder interferometer provided on a silicon substrate;

a single said polarization control structure comprises two input ports and one output port; the single Mach-Zehnder interferometer comprises two input ports and an optical signal output port, and the optical signal output port is used for outputting a combined wave optical signal; the output port of the polarization control structure is connected with the input port of the Mach-Zehnder interferometer;

the single polarization control structure receives two paths of linearly polarized light in the incident linearly polarized light, synthesizes a path of secondary wave-combining optical signal with two linear polarization states which are vertical to each other, outputs the secondary wave-combining optical signal and inputs the secondary wave-combining optical signal through one input port of the Mach-Zehnder interferometer; and the at least one polarization-independent Mach-Zehnder interferometer receives the secondary wave-combined optical signals output by the at least two polarization control structures, and combines the secondary wave-combined optical signals into a path of wave-combined optical signal with two linear polarization states which are vertical to each other to output.

As a further refinement of the embodiment, the wavelength division multiplexer comprises n polarization control structures and n-1 polarization independent mach-zehnder interferometers, where n is an integer greater than or equal to 2.

As a further improvement of the embodiment, the polarization control structure is an integrated polarization rotator-combiner.

As a further improvement of the embodiment, the integrated polarization rotation-beam combiner includes a through waveguide and a cross waveguide, a through port and a cross port connecting the through waveguide and the cross waveguide, respectively, and a mode conversion structure connecting the through waveguide; the through waveguide and the cross waveguide form a mode multiplexing structure; the through port and the cross port both comprise a wedge-shaped structure of a strip waveguide-ridge waveguide; the mode conversion structure is a double-layer wedge-shaped mode conversion structure.

As a further improvement of the embodiment, the polarization control structure includes a polarization rotator and a polarization beam combiner.

As a further improvement of the embodiment, the polarization beam combiner comprises three identical mode conversion couplers, and a single mode conversion coupler comprises a single-mode access waveguide and a multi-mode bus waveguide;

the first mode conversion coupler and the second mode conversion coupler of the three mode conversion couplers are arranged in parallel, the multimode bus waveguide of the third mode conversion coupler is connected with the multimode bus waveguide of the first mode conversion coupler, and the single-mode access waveguide is connected with the output end of the single-mode access waveguide of the second mode conversion coupler.

As a further improvement of the embodiment, a single mach-zehnder interferometer comprises a 2 × 2 input 3dB coupler, two phase shift arms, and a 2 × 2 output 3dB coupler connected in sequence; at least one of the two phase shifting arms is a phase-variable shifting arm;

the input 3dB coupler and the output 3dB coupler are both polarization-independent couplers, and the phase shift arms are both provided with polarization rotators.

As a further improvement of the embodiment, the mach-zehnder interferometer further includes a monitor detector optically connected to one output port of the output 3dB coupler.

The application also provides a silicon optical integrated chip, which comprises the wavelength division multiplexer in any embodiment.

As a further improvement of the embodiment, the silicon optical integrated chip further comprises an optical modulator; after the multiple paths of incident light signals are modulated by the optical modulator, the multiple paths of modulated light signals are output; the multi-path modulation optical signals are respectively input through an input port of a polarization control structure of the wavelength division multiplexer, and output a path of wave combination optical signal after passing through the polarization control structure and the Mach-Zehnder interferometer.

The beneficial effect of this application: the polarization control structure capable of designing the bandwidth is adopted, the optical bandwidth of the wavelength division multiplexer is improved, and the optical loss is reduced; the number of phase shift arms needing to adjust feedback is reduced, and the overall power consumption of the device is reduced; and the polarization control structure has large manufacturing tolerance and good stability, and can effectively improve the reliability and yield of the wavelength division multiplexer.

Drawings

FIG. 1 is a schematic diagram of a MZI type wavelength division multiplexer in a current silicon optical system;

fig. 2 is a schematic structural diagram of a wavelength division multiplexer according to embodiment 1 of the present application;

FIG. 3 is a schematic diagram of the integrated silicon-based polarization rotator-combiner (PSR) in example 1;

FIG. 4 is a schematic diagram of a polarization independent 2X 2 input 3dB coupler structure;

FIG. 5 is a schematic diagram of a polarization independent 2X 2 output 3dB coupler structure;

FIG. 6 is a schematic diagram of a Polarization Rotator (PR);

fig. 7 is a schematic structural diagram of a wavelength division multiplexer according to embodiment 2 of the present application;

fig. 8 is a schematic diagram of a Polarization Beam Combiner (PBC) structure;

fig. 9 is a schematic diagram of an extended structure of the wavelength division multiplexer according to the present application;

FIG. 10 is a schematic diagram of another extended structure of the wavelength division multiplexer according to the present application;

fig. 11 is a schematic view of a silicon photonic integrated chip according to embodiment 3 of the present application.

Detailed Description

The present application will now be described in detail with reference to specific embodiments thereof as illustrated in the accompanying drawings. These embodiments are not intended to limit the present application, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present application.

In the various illustrations of the present application, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for ease of illustration and, thus, are provided to illustrate only the basic structure of the subject matter of the present application.

Also, terms used herein such as "upper," "above," "lower," "below," and the like, denote relative spatial positions of one element or feature with respect to another element or feature as illustrated in the figures for ease of description. The spatially relative positional terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. When an element or layer is referred to as being "on," or "connected" to another element or layer, it can be directly on, connected to, or intervening elements or layers may be present.

Example 1

The wavelength division multiplexer of the present application comprises a silicon-based substrate, a buried oxide layer, a waveguide layer and an upper cladding layer, as shown in fig. 2, on which at least two polarization control structures 200 and at least one polarization independent mach-zehnder interferometer 100 are provided. The single polarization control structure 200 includes two input ports and one output port, and the single mach-zehnder interferometer 100 includes two input ports and one optical signal output port for outputting a combined wave optical signal; the output port of the polarization control structure 200 is connected to the input port of the mach-zehnder interferometer. The single polarization control structure 200 receives two linear polarized light beams in the incident linear polarized light beam, synthesizes a sub-wave-combination optical signal with two linear polarization states perpendicular to each other, outputs the sub-wave-combination optical signal, and inputs the sub-wave-combination optical signal through an input port of the mach-zehnder interferometer 100. The at least one polarization-independent mach-zehnder interferometer 100 receives the sub-combined optical signals output by the at least two polarization control structures 200, and combines the sub-combined optical signals into a combined optical signal with two linear polarization states perpendicular to each other for output. The wavelength division multiplexer adopts a polarization control structure capable of designing the bandwidth, so that the optical bandwidth of the wavelength division multiplexer is improved, and the optical loss is reduced; the number of phase shift arms needing to adjust feedback is reduced, and the overall power consumption of the device is reduced; and the polarization control structure has large manufacturing tolerance and good stability, and can effectively improve the reliability and yield of the wavelength division multiplexer.

As shown in fig. 2-6, a four-wavelength division multiplexer, for example, includes two polarization control structures 200 in parallel and a mach-zehnder interferometer 100. In this embodiment, a single polarization control structure 200 employs an integrated polarization rotator-combiner (PSR), and as shown in fig. 3, the integrated polarization rotator-combiner 210 includes a through waveguide 211 and a cross waveguide 212, a through port 213 and a cross port 214 connecting the through waveguide 211 and the cross waveguide 212, respectively, and a mode transforming structure 215 connecting the through waveguide 211. Here, the through waveguide 211 and the cross waveguide 212 form a mode multiplexing structure, and the through port 213 and the cross port 214 each include a wedge structure of a strip waveguide-ridge waveguide, which is an input port of the polarization control structure. The mode conversion structure 215 is a double-layer wedge-shaped mode conversion structure, and is used as an output port of the polarization control structure to output a composite optical signal.

In this embodiment, the polarization independent mach-zehnder interferometer 100 includes a 2 x 2 input 3dB coupler 110, two phase shifting arms 130, and a 2 x 2 output 3dB coupler 120 connected in series, at least one of the two phase shifting arms 130 being a phase-shiftable arm, as represented by the dashed lines in fig. 2. Here, the input 3dB coupler 110 and the output 3dB coupler 120 are both Polarization Independent (PI) 3dB couplers, i.e., "PI 0.5", and the polarization rotator 140 is also provided on the phase shift arm 130. Two ports of the input end of the input 3dB coupler 110 are used as input ports of the mach-zehnder interferometer 100, one of the two ports of the output end of the output 3dB coupler 120 is used as an optical signal output port of the mach-zehnder interferometer 100 to output a composite wave beam, and the other port is optically connected with a monitoring detector (MPD)150 for feeding back the tuning condition of the phase-adjustable shift arm.

As shown in fig. 6, the Polarization Rotator (PR)140 includes a ridge waveguide 141 and a partial planar waveguide 142 at one side of the ridge waveguide 141. The ridge waveguide 141 includes a first wedge-shaped structure 141a, a linear structure 141b, and a second wedge-shaped structure 141c, which are connected in sequence, where the first wedge-shaped structure 141a is used as an input end of the polarization rotator 140, and has a width gradually narrowing along the optical path direction until being connected to the linear structure 141b, and the second wedge-shaped structure 141c has a width gradually widening along the optical path direction until being connected to the optical waveguide of the phase shift arm. The height of the partial planar waveguide 142 is lower than that of the ridge waveguide 141, and includes a third wedge structure 142a and a fourth wedge structure 142b located on the same side of the ridge waveguide 141 and connected to each other. The third wedge-shaped structure 142a is adjacent to the side of the first wedge-shaped structure 141a, the fourth wedge-shaped structure 142b is adjacent to the side of the linear structure 141b, the tip of the third wedge-shaped structure 142a is adjacent to the side of the wider end of the first wedge-shaped structure 141a, and the tip of the fourth wedge-shaped structure 142b is adjacent to the narrower end of the second wedge-shaped structure 141 c. Linearly polarized light is incident from the wider end of the first wedge-shaped structure 141a of the ridge waveguide 141, and in the first wedge-shaped structure 141a and the linear structure 141b, the optical mode is distributed into the ridge waveguide 141 and the planar waveguide 142, causing the polarization state thereof to rotate, and the polarization direction has been rotated by 90 degrees when incident to the second wedge-shaped structure 141c, and is coupled into the optical waveguide of the phase shift arm through the second wedge-shaped structure 141 c. In other embodiments, a polarization rotator-combiner (PSR) shown in fig. 3 may be used as the polarization rotator, and linearly polarized light enters from the cross port, is coupled to the through waveguide through the cross waveguide, and finally is output by the mode conversion structure after being rotated by 90 degrees.

In operation, of four wavelengths of optical signals, λ 1, λ 2, λ 3 and λ 4, whose modes are all linearly polarized as TE0, λ 1 and λ 3 are input from the through port 213 and the cross port 214, respectively, of one of the integrated polarization rotating-beam combiners (PSRs) 210, and enter the through waveguide 211 and the cross waveguide 212, respectively. The mode of the λ 1 optical signal in the through waveguide 211 is unchanged, and the mode conversion structure 215 still outputs the λ 1 optical signal in the TE0 mode; the λ 3 optical signal in the cross waveguide 212 is coupled into the through waveguide 211, and is mode-multiplexed with the optical signal in the through waveguide 211, the λ 3 optical signal mode is converted into TE1, and is converted into a TM0 mode by the mode conversion structure 215, and is combined with the λ 1 optical signal in the TE0 mode in the original through waveguide 211 into a λ 1 and λ 3 sub-combined optical signal including a TE0+ TM0 mode. Similarly, λ 2 and λ 4 are respectively input from the through port 213 and the cross port 214 of another integrated polarization rotating-beam combiner (PSR)210, and respectively enter the through waveguide 211 and the cross waveguide 212, and finally, a sub-combined optical signal containing λ 4 of the λ 2 and TM0 modes of the TE0 mode is output by the mode transformation structure 215. The two sub-wavelength optical signals λ 1(TE0) + λ 3(TM0) and λ 2(TE0) + λ 4(TM0) are respectively input from two input ports of the polarization-independent 2 × 2 input 3dB coupler 110 of the mach-zehnder interferometer 100, λ 1(TE0)/λ 2(TE0)/λ 3(TM0)/λ 4(TM0) of the optical power transmitted 1/2 in the two phase shift arms 130, respectively, and after the polarization direction of each wavelength of light is rotated by 90 ° by the polarization rotator 140 in the phase shift arm 130, the polarization state of each wavelength of light becomes λ 1(TM0)/λ 2(TM0)/λ 3(TE0)/λ 4(TE 0). The phase difference between the TE mode and the TM mode in the two phase shift arms 130 is controlled by adjusting the phase-adjustable shift arms in conjunction with the polarization rotators 140 on the two phase shift arms 130 so that the optical signals in the two phase shift arms 130 are both output from the same port of the polarization independent output 3dB coupler 120 and the monitor detector 150 at the other port detects near zero optical power, i.e., the combined wave optical signals λ 1(TM0)/λ 2(TM0)/λ 3(TE0)/λ 4(TE0) are output by one port of the 2 × 2 output 3dB coupler 120 of the mach-zehnder interferometer 100. The optical power at the other output port of the output 3dB coupler 120 can be monitored by the monitor detector 150 while adjusting the phase-shifting arm until the optical power at that output port is zero or near zero, or at a minimum. If the phase of the output light is changed by the influence of environment or other factors, so that the output light can not be completely combined with another path of light to output, the monitoring detector detects that the optical power is increased, the optical power is fed back to the controller, and the phase of the phase-adjustable phase-shifting arm is adjusted by the controller until the optical power detected by the monitoring detector approaches zero or a minimum value again.

The four-wavelength division multiplexer adopts two passive polarization control structures with designable bandwidth, reduces the bandwidth limitation of a 3dB coupler, improves the optical bandwidth of the wavelength division multiplexer and reduces the optical loss. In the working process, wavelength division multiplexing of four wavelengths can be realized only by adjusting one phase shift arm, the number of the phase shift arms needing to adjust feedback is small, and the overall power consumption of the device is reduced; and the polarization control structure has large manufacturing tolerance and good stability, and can effectively improve the reliability and yield of the wavelength division multiplexer.

Example 2

As in the embodiment shown in fig. 7 and 8, unlike embodiment 1, the single Polarization control structure 200 in this embodiment includes a Polarization Rotator (PR) 220 and a Polarization Beam Combiner (PBC) 230. In this embodiment, the polarization rotator 220 has a structure as shown in fig. 6, and similar to the structure of the polarization rotator in embodiment 1, and includes a ridge waveguide and a portion of a planar waveguide located at one side of the ridge waveguide, which is not described herein again. In other embodiments, a polarization rotator-combiner (PSR) shown in fig. 3 may be used as the polarization rotator, and linearly polarized light enters from the cross port, is coupled to the through waveguide through the cross waveguide, and finally is output by the mode conversion structure after being rotated by 90 degrees.

As shown in fig. 8, the polarization beam combiner 230 includes three identical mode conversion couplers 231, 232, and 233, and a single mode conversion coupler includes a single-mode access waveguide and a multi-mode bus waveguide. The first mode conversion coupler 231 and the second mode conversion coupler 232 are parallel and located at the input end of the polarization beam combiner, and the single-mode access waveguides 231a and 232a of the two mode conversion couplers 232 and 232 are respectively connected with the output port of the polarization rotator and the input port of the wavelength division multiplexer. The third mode conversion coupler 233 is cascaded with the two mode conversion couplers 231 and 232, the multimode bus waveguide 233b of the third mode conversion coupler 233 is connected to the output end of the multimode bus waveguide 231b of the first mode conversion coupler 231, and the single-mode access waveguide 233a is connected to the output end of the single-mode access waveguide 232a of the second mode conversion coupler 232.

Taking a four-wavelength division multiplexer as an example, in the working process, in the optical signals with four wavelengths of λ 1, λ 2, λ 3 and λ 4 whose modes are TE linear polarization, λ 1 and λ 3 are respectively input from two input ports of one of the polarization control structures 200. Wherein λ 1 is directly incident on the polarization beam combiner 230, λ 3 is rotated by 90 degrees by the polarization rotator 220, and the linearly polarized light converted into TM mode is re-incident on the polarization beam combiner 230, and λ 1 of TE mode and λ 3 of TM mode are combined into a sub-combined optical signal λ 1(TE)/λ 3(TM) by the polarization beam combiner 230 and output. Similarly, λ 2 and λ 4 are respectively input from two input ports of another polarization control structure 200, λ 2 is directly incident on the polarization beam combiner 230, λ 4 is rotated by 90 degrees by the polarization rotator 220, and the linearly polarized light that becomes TM mode is then incident on the polarization beam combiner 230, and λ 2 of TE mode and λ 4 of TM mode are combined into the sub-combined optical signal λ 2(TE)/λ 4(TM) by the polarization beam combiner 230 and output. The two sub-wavelength optical signals λ 1(TE0) + λ 3(TM0) and λ 2(TE0) + λ 4(TM0) are respectively input from two input ports of the polarization-independent 2 × 2 input 3dB coupler 110 of the mach-zehnder interferometer 100, λ 1(TE0)/λ 2(TE0)/λ 3(TM0)/λ 4(TM0) of the optical power transmitted 1/2 in the two phase shift arms 130, respectively, and after the polarization direction of each wavelength of light is rotated by 90 ° by the polarization rotator 140 in the phase shift arm 130, the polarization state of each wavelength of light becomes λ 1(TM0)/λ 2(TM0)/λ 3(TE0)/λ 4(TE 0). The phase difference between the TE mode and the TM mode in the two phase shift arms 130 is controlled by adjusting the phase-adjustable shift arms in conjunction with the polarization rotators 140 on the two phase shift arms 130 so that the optical signals in both phase shift arms are output from the same port of the polarization independent output 3dB coupler 120 and the monitor detector 150 at the other port detects an optical power approaching zero or a minimum value, i.e., the combined wave optical signal λ 1(TM0)/λ 2(TM0)/λ 3(TE0)/λ 4(TE0) is output by one port of the 2 × 2 output 3dB coupler 120 of the mach-zehnder interferometer 110.

In the embodiment, the polarization beam combiner composed of the three mode conversion couplers is combined with the polarization rotator to perform polarization beam combination on two paths of incident light signals with the same linear polarization state, so that crosstalk is reduced. And because the mode conversion coupler has the characteristics of low loss and large bandwidth, the optical loss is further reduced, and the optical bandwidth of the device is improved.

In the above embodiments 1 and 2, the wavelength division multiplexing of four wavelengths is taken as an example for explanation, but in other embodiments, the wavelength division multiplexer may also be used for wavelength division multiplexing of other multiple wavelengths, and the polarization control structures and the mach-zehnder interferometers may be arranged in parallel or in cascade in a corresponding number according to the number of wavelength channels to be multiplexed. That is, the wavelength division multiplexer includes n polarization control structures and n-1 polarization independent mach-zehnder interferometers, where n is an integer greater than or equal to 2, and when n is 2, the wavelength division multiplexer with 4 wavelengths is described above. As shown in fig. 9 and 10, when n is 3 and n is 4, the wavelength division multiplexer is extended to 6-wavelength channels and 8-wavelength channels, but more extensions are possible.

Example 3

As shown in fig. 11, this embodiment provides a silicon photonic integrated chip including an optical modulator 300 and the wavelength division multiplexer of any of the above embodiments. After the multiple incident light signals are modulated by the optical modulator 300, the multiple modulated light signals are output. The multi-path modulated optical signals are respectively input through each input port of the wavelength division multiplexer, and output a path of wave-combined optical signal after being combined by the polarization control structure 200 and the mach-zehnder interferometer 100. The silicon optical integrated chip integrates the wavelength division multiplexer of any one of the embodiments for wavelength division multiplexing, so that the power consumption of the device can be effectively reduced, the optical bandwidth is improved, and the reliability and yield of the product are improved.

The above list of details is only for the concrete description of the feasible embodiments of the present application, they are not intended to limit the scope of the present application, and all equivalent embodiments or modifications that do not depart from the technical spirit of the present application are intended to be included within the scope of the present application.