WO2022257841A1

WO2022257841A1 - Optical polarization state control apparatus and optical polarization state control method

Info

Publication number: WO2022257841A1
Application number: PCT/CN2022/096745
Authority: WO
Inventors: 曹军涛; 桂韬; 卢彦兆
Original assignee: 华为技术有限公司
Priority date: 2021-06-08
Filing date: 2022-06-02
Publication date: 2022-12-15
Also published as: CN115453775A

Abstract

An optical polarization state control apparatus (300), used for reducing the volume of an optical polarization state control device, and reducing the complexity of polarization state control for optical signals. The optical polarization state control apparatus (300) comprises a detection module (302), a control circuit module (303), and a polarization control module (301). The detection module (302) is used for acquiring first polarization state information and second polarization state information of a target beam, the first polarization state information being polarization information before the target beam enters the polarization control module (301), and the second polarization state information being polarization information after the target beam is emitted from the polarization control module (301). The control circuit module (303) is used for determining a target control voltage according to the first polarization state information and the second polarization state information of the target beam. The polarization control module (301) is used for regulating the polarization state of the target beam according to the target control voltage.

Description

A device for controlling the polarization state of light and a method for controlling the polarization state of light

This application claims the priority of the Chinese patent application with the application number 202110639367.8 and the title of the invention "A device for controlling the polarization state of light and a method for controlling the polarization state of light" submitted to the China Patent Office on June 08, 2021. The entire contents are incorporated by reference in this application.

technical field

The embodiments of the present application relate to the field of optical signal processing, and in particular, to an optical polarization state control device and a method for controlling the optical polarization state.

Background technique

In the field of optical fiber communication, the polarization problem in the process of optical fiber transmission signal is often dealt with in the optical domain.

Among the existing solutions, to solve the polarization problem in the process of optical fiber transmission signal in the optical domain, the most commonly used method is to control the polarization state of the optical signal through the polarization control technology of cascaded multi-stage waveplates. For example, in a multi-stage wave plate cascaded polarization control device, according to the incident order of optical signals, the multi-stage wave plate includes a 1/4 wave plate, a 1/2 wave plate and a 1/4 wave plate. The multi-stage wave plate cascaded polarization control device sequentially adjusts the main axis direction of each wave plate by acquiring the feedback signal of the optical signal, so that the polarization state of the optical signal is kept stably at the target position.

For the existing signal polarization state control method, since the polarization control device includes multiple wave plates, the volume of the polarization control device is relatively large; the polarization control device needs to control multiple wave plates, so the control The complexity is higher and the control speed is slower; on the other hand, the device needs to obtain the full-field information of the optical signal in order to obtain the feedback information of the optical signal, so the detection structure of the device is also more complicated.

Contents of the invention

An embodiment of the present application provides an optical polarization state control device, which is used to reduce the volume of the device and reduce the complexity of controlling the polarization state of an optical signal.

The first aspect of the embodiment of the present application provides a light polarization control device, the light polarization control device includes: a detection module, a control circuit module and a polarization control module; the detection module is used to obtain the first polarization state information and The second polarization state information, the first polarization state information is the polarization information before the target beam enters the polarization control module, and the second polarization state information is the polarization information after the target beam exits the polarization control module; the control circuit module is used to The first polarization state information and the second polarization state information determine a target control voltage; the polarization control module is used to adjust the polarization state of the target beam according to the target control voltage.

In this possible implementation, the optical polarization control device adjusts the polarization state of the target beam through the polarization control module, instead of adjusting the polarization state of the light through a large multi-stage wave plate, thereby greatly reducing the The volume of the light polarization state control device; at the same time, the light polarization state control device only needs to adjust and control the polarization control module, which reduces the control objects, makes the control speed faster, and greatly reduces the complexity of control; on the other hand, the embodiment of the present application The optical polarization state control device in the present invention only needs to obtain the polarization state information before and after the target beam enters the polarization control module, which reduces the amount of information to be obtained and can have a simpler structure.

In a possible implementation manner of the first aspect, the above-mentioned polarization control module includes a polarization beam splitter, a polarization rotation combiner, and a polarization control unit; The polarized light in the first direction and the polarized light in the second direction, the first direction and the second direction are perpendicular to each other; the polarization rotation combiner is used to combine the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control unit into the target light beam; the polarization control unit is used to adjust the polarization state of the polarized light in the first direction and the polarized light in the second direction according to the target control voltage, and the adjustment amount of the polarized light in the first direction and the polarized light in the second direction by the polarization control unit is the same as Target control voltage dependent.

In this possible implementation, the polarization beam splitter divides the target beam into polarized light in the first direction and polarized light in the second direction before it enters the polarization control unit, so that the polarization control unit can directly polarize the target beam in the corresponding direction The light is adjusted, and then the polarization rotation combiner combines the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control module into the target beam, which reduces the influence on the target beam; at the same time, it specifically provides a polarization The structure of the control module improves the realizability of the embodiment of the present application.

In a possible implementation of the first aspect, the detection module includes a first photoelectric conversion circuit, a second photoelectric conversion circuit, a first current-voltage conversion circuit, and a second current-voltage conversion circuit; the first photoelectric conversion circuit is used to Determine the first current according to the target beam before the incident polarization control module; the second photoelectric conversion circuit is used to determine the second current according to the target beam after the output polarization control module; the first current-voltage conversion circuit is used to determine the first current according to the first current Voltage; the second current-voltage conversion circuit is used to determine the second voltage according to the second current.

In a possible implementation manner of the first aspect, the control circuit module includes a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a digital-to-analog conversion circuit, and a processor; the first analog-to-digital conversion circuit is used to The voltage determines the first polarized light power of the target beam before the incident polarization control module; the second analog-to-digital conversion circuit is used to determine the second polarized light power of the target beam after the outgoing polarization control module according to the second voltage; The first polarized light power, the second polarized light power and the parameters of the polarization control module determine the adjustment step; the digital-to-analog conversion circuit is used to determine the target control voltage according to the adjustment step.

In a possible implementation manner of the first aspect, the detection module further includes a multi-mode interference beam splitter; the multi-mode interference beam splitter is used to divide the polarized light in the first direction of the target beam after exiting the polarization control module and The polarized light in the second direction obtains an interference beam through interference; the second photoelectric conversion circuit is also used to determine a third current according to the interference beam; the second current-voltage conversion circuit is also used to determine a third voltage according to the third current.

In this possible implementation manner, the detection module further includes a multi-mode interference beam splitter, so that the detection module can obtain more information, thereby improving the polarization tracking capability.

In a possible implementation of the first aspect, the second analog-to-digital conversion circuit is further configured to determine the third polarized light power of the target beam after exiting the polarization control module according to the third voltage; The power, the power of the second polarized light, the power of the third polarized light and the parameters of the polarization control module determine the adjustment step size.

In a possible implementation manner of the first aspect, the polarization control unit is configured to adjust the power of the polarized light in the first direction to be equal to the power of the polarized light in the second direction, and the first direction and the second direction are perpendicular to each other.

In a possible implementation manner of the first aspect, the polarization control unit includes a secondary phase modulator, the secondary phase modulator includes a first phase modulator and a second phase modulator, and the first phase modulator is used to adjust the target light beam, the second phase modulator is used to adjust the target beam exiting the first phase modulator.

The second aspect of the embodiment of the present application provides a method for controlling the polarization state of light, which is characterized in that it is applied to a light polarization state control device, and the light polarization state control device includes a detection module, a control circuit module, and a polarization control module. The method includes: Obtain the first polarization state information and the second polarization state information of the target beam through the detection module, the first polarization state information is the polarization information before the target beam enters the polarization control module, and the second polarization state information is after the target beam exits the polarization control module The polarization information of the target beam is determined by the control circuit module according to the first polarization state information and the second polarization state information of the target beam; the polarization state of the target beam is adjusted by the polarization control module according to the target control voltage.

In a possible implementation of the second aspect, the polarization control module includes a polarization beam splitter, a polarization rotation combiner, and a polarization control unit; the target beam before entering the polarization control module is divided into a first direction by the polarization beam splitter The polarized light of the polarized light and the polarized light of the second direction, the first direction and the second direction are perpendicular to each other; the polarized light of the first direction and the polarized light of the second direction after exiting the polarization control module are combined into the target beam through the polarization rotation combiner ; adjust the polarization state of the target beam through the polarization control unit.

In a possible implementation of the second aspect, the detection module includes a first photoelectric conversion circuit, a second photoelectric conversion circuit, a first current-voltage conversion circuit, and a second current-voltage conversion circuit. The first polarization state information and the second polarization state information include: determining the first current through the first photoelectric conversion circuit according to the target beam before the incident polarization control module; determining the first current according to the target beam after the outgoing polarization control module through the second photoelectric conversion circuit the second current; the first voltage is determined according to the first current through the first current-voltage conversion circuit; the second voltage is determined according to the second current through the second current-voltage conversion circuit.

In a possible implementation of the second aspect, the control circuit module includes a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a digital-to-analog conversion circuit, and a processor. The polarization state information and the second polarization state information determine the target control voltage, including: the first analog-to-digital conversion circuit is used to determine the first polarized light power of the target beam before the incident polarization control module according to the first voltage; the second analog-to-digital conversion circuit It is used to determine the second polarized light power of the target beam after exiting the polarization control module according to the second voltage; the processor is used to determine the adjustment step according to the parameters of the first polarized light power, the second polarized light power and the polarization control module; digital-analog The conversion circuit is used to determine the target control voltage according to the adjustment step size.

In a possible implementation manner of the second aspect, the detection module further includes a multi-mode interference beam splitter, and the above method further includes: using the multi-mode interference beam splitter to divide the first part of the target beam exiting the polarization control module The polarized light in one direction and the polarized light in the second direction are interfered to obtain an interference beam; the second photoelectric conversion circuit is used to determine the third current according to the interference beam; the second current-voltage conversion circuit is used to determine the third voltage according to the third current.

In a possible implementation of the second aspect, the above method further includes: using the second analog-to-digital conversion circuit to determine the third polarized light power of the target beam after exiting the polarization control module according to the third voltage; using the processor according to the first The first polarized light power, the second polarized light power, the third polarized light power and the parameters of the polarization control module determine the adjustment step size.

In a possible implementation manner of the second aspect, the above-mentioned adjustment of the polarization state of the target beam by the polarization control unit includes: adjusting the polarization power of the target beam in the first direction and the polarization power in the second direction of the target beam by the polarization control unit according to the target control voltage The polarized light powers are equal, and the first direction and the second direction are perpendicular to each other.

In a possible implementation manner of the second aspect, the polarization control unit includes a secondary phase modulator, and the secondary phase modulator includes a first phase modulator and a second phase modulator, and the polarization control unit adjusts the target beam The polarization state includes: adjusting the target beam through the first phase modulator, and adjusting the target beam exiting the first phase modulator through the second phase modulator.

It can be seen from the above technical solutions that the embodiment of the present application has the following advantages: the light polarization state control device adjusts the polarization state of the target beam through the polarization control module, instead of adjusting the polarization state of light through a large multi-stage wave plate method, thereby greatly reducing the volume of the optical polarization state control device; at the same time, the optical polarization state control device only needs to adjust and control the polarization control module, reducing the number of control objects, making the control speed faster and the control complexity greatly reduced; On the other hand, the light polarization state control device in the embodiment of the present application only needs to obtain the polarization state information before and after the target beam enters the polarization control module, which reduces the amount of information to be obtained and can have a simpler structure.

Description of drawings

Fig. 1 is a kind of structural schematic diagram of multistage wave plate cascaded polarization control device;

FIG. 2 is a schematic diagram of a structure of an optical polarization state control device according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of an optical polarization state control device according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a detection module according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of a control circuit module according to an embodiment of the present application;

Fig. 6 is another schematic structural diagram of the detection module of the embodiment of the present application;

FIG. 7 is another schematic structural diagram of the control circuit module of the embodiment of the present application;

FIG. 8 is another structural schematic diagram of the light polarization state control device according to the embodiment of the present application;

FIG. 9 is a schematic structural diagram of a phase modulator according to an embodiment of the present application;

FIG. 10 is a flowchart of a method for controlling the state of polarization of light according to an embodiment of the present application;

FIG. 11 is another flow chart of the light polarization state control method of the embodiment of the present application;

FIG. 12 is another flow chart of the method for controlling the polarization state of light according to the embodiment of the present application.

Detailed ways

An embodiment of the present application provides an optical polarization state control device, which is used to reduce the volume of an optical polarization state control device and reduce the complexity of the polarization state control of an optical signal.

Embodiments of the present application are described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Those of ordinary skill in the art know that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

The terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

As shown in FIG. 1 , in the field of optical fiber communication, the polarization problem occurring in the process of optical fiber transmission signal is often dealt with in the optical domain. After the emergence of coherent digital signal processing (Digital Signal Processing, DSP) technology, the polarization problem has gradually begun to be solved in the digital domain. The solutions in the optical domain are the main ones. Among the existing solutions, to solve the polarization problem in the process of optical fiber transmission signal in the optical domain, the most commonly used method is to control the polarization state of the optical signal through the polarization control technology of cascaded multi-stage waveplates. For example, in a multi-stage wave plate cascaded polarization control device, according to the incident order of optical signals, the multi-stage wave plate includes a 1/4 wave plate, a 1/2 wave plate and a 1/4 wave plate. The multi-stage wave plate cascaded polarization control device sequentially adjusts the main axis direction of each wave plate by acquiring the feedback signal of the optical signal, so that the polarization state of the optical signal is kept stably at the target position. For the existing signal polarization state control method, since the polarization control device includes a plurality of wave plates, the volume of the polarization control device is too large, for example, for data centers, one of the application scenarios of bidirectional (BIDI) technology In the network (Data Center Network, DCN) scenario, the multiple wave plates are too large to be packaged into a standard module; the polarization control device needs to control multiple wave plates, so the control complexity is higher, and the control The speed is also slower. For example, in the DCN scenario, the polarization state change frequency of the optical signal is on the order of KHz, which requires the control speed of the polarization controller to reach the order of microseconds us or even nanoseconds ns. This is the existing optical domain polarization On the other hand, the device needs to obtain the full-field information of the optical signal in order to obtain the feedback information of the optical signal, so the detection structure of the device is also more complicated.

As shown in Figure 2, an embodiment of the present application provides a polarization control device, which is used in any scenario where the polarization state of an optical signal needs to be adjusted, for example, the device can be applied to a BIDI system in a BIDI scenario, such as the The BIDI system may include a distributed feedback laser, a modulator, a transmission link, a polarization control device, and an integrated coherent receiver. The polarization control device includes a polarization control unit, a detection module, and a control circuit module. The detection module includes a coarse wavelength division multiplexing The control circuit module includes a transceiver digital signal processor, a digital-to-analog converter and an analog-to-digital converter.

Specifically, part of the target beam emitted from the distributed feedback laser is modulated by the modulator, and then the optical signal is transmitted to the integrated coherent receiver through the coarse wavelength division multiplexer, so that the integrated coherent receiver can obtain the unintended The first polarization state information of the target beam adjusted by the polarization control unit; the other part passes the coarse wavelength division multiplexer to enter the unmodulated target beam into the polarization control unit, and after the adjustment of the polarization control unit, the optical signal is transmitted to the integrated coherent receiver, so that the integrated coherent receiver acquires the second polarization state information of the target beam adjusted by the polarization control unit; then the integrated coherent receiver transmits the first polarization state information and the second polarization state information to the digital Signal processor, the digital signal processor determines the control voltage according to the first polarization state information and the second polarization state information, and then loads the control voltage to the polarization control unit through the analog-to-digital converter, so as to realize the polarization state control of the target beam control.

As shown in FIG. 3 , an embodiment of the present invention provides an optical polarization state control device 300, which will be described in detail below:

The polarization state control device 300 includes: a polarization control module 301, a detection module 302 and a control circuit module 303;

The polarization control module 301 is used for adjusting the polarization state of the target light beam according to the target control voltage. The polarization control module 301 includes a polarization beam splitter (Polarization Splitter, PSR) 304, a polarization control unit 305, and a polarization rotator combiner (Polarization rotator combiner, PRC) 306.

Specifically, the polarization beam splitter 304 is used to split the target beam before entering the polarization control unit into the polarized light in the first direction and the polarized light in the second direction, that is, to divide the target beam not adjusted by the polarization control unit into the first polarized light in one direction and polarized light in a second direction, the first direction and the second direction are perpendicular to each other and perpendicular to the transmission direction of the target light beam.

The polarization control unit 305 is used to adjust the polarization state of the polarized light in the first direction and the polarized light in the second direction according to the target control voltage, and the control circuit module loads the target control voltage on the polarization control unit 305 with the polarization control unit for the second The adjustment amount of the polarization state of the polarized light in one direction is related to the polarization state of the polarized light in the second direction. Specifically, the polarization control unit adjusts the polarized light power of the polarized light in the first direction and the polarized light power of the polarized light in the second direction to be equal, so that the target beam can normally load the corresponding information without a The power of the signal light in the direction is zero, so it cannot be beat with the signal light, that is, there will be no situation where the target beam cannot carry the loaded information; the above-mentioned target beam includes local oscillator light (Local Oscillation, LO), and the local oscillator light without any information loaded The corresponding information can be loaded by modulation.

Specifically, the adjustment amount of the polarization state of the polarized light in the first direction and the polarized light in the second direction by the polarization control unit 305 is related to the target control voltage, that is, by changing the control circuit module loaded on the polarization control The target control voltage of the unit is used to change the adjustment amount of the polarization control unit for the polarized light in the first direction and the polarized light in the second direction. For example, the control parameters of the polarization control unit include a reference voltage. If the target control voltage is greater than the reference voltage, the adjustment amount of the polarization control unit to the polarized light in the first direction and the polarized light in the second direction is positive; if the target control voltage is less than the reference voltage, the adjustment amount of the polarization control unit to the polarized light in the first direction and the polarized light in the second direction is negative, and the greater the difference between the target control voltage and the reference voltage, the adjustment value of the polarization control unit to the polarized light in the first direction The adjustment amount of the polarized light in the second direction is larger.

The polarization rotation combiner 306 is used to combine the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control unit into a target beam, that is, the polarized light in the first direction and the polarized light in the second direction that have been adjusted by the polarization control unit The polarized light is combined into the target beam, and the first direction and the second direction are consistent with the first direction and the second direction of the above-mentioned polarization beam splitter 304 .

In the embodiment of the present application, the polarization beam splitter divides the target beam into polarized light in the first direction and polarized light in the second direction, and then the polarization control unit determines the polarization states of the polarized light in the first direction and the polarized light in the second direction After adjustment, the polarization rotation combiner then combines the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control unit into the target beam, so as to realize the adjustment of the polarization state of the target beam.

In a possible implementation manner, the polarization control module 301 may include a polarization beam splitter 304 and a polarization control unit 305 instead of a polarization rotation combiner 306, for example, when the polarization control module is combined with an integrated coherent receiver (Integrated Coherent Receiver, ICR) work together, the polarization control module does not need to include the polarization rotation combiner.

Specifically, the polarization control unit may include a secondary phase modulator, the secondary phase modulator includes a first phase modulator and a second phase modulator, the first phase modulator is used to control the voltage according to the target Adjusting the polarization state of the polarized light in the first direction and the polarized light in the second direction, the second phase modulator is used to adjust the second phase of the polarized light in the first direction exiting the first phase modulator according to the target control voltage The polarization state of polarized light in two directions. That is, the first phase modulator and the second phase modulator can form a two-stage phase modulator, and the polarization state of the polarized light in the first direction incident on the polarization control unit and the polarized light in the second direction pass through the first phase modulator first. After the adjustment, the second phase modulator is adjusted, so that the polarization control unit can adjust the polarization state of the polarized light in the first direction and the polarization state of the polarized light in the second direction.

In the embodiment of the present application, the polarization control unit includes a two-stage phase modulator. In addition, the polarization control unit can also be a phase modulator, a multi-level phase modulator including more than two phase modulators, or a niobium phase modulator. A device such as a 1/2 wave plate of lithium acid material that can adjust the polarization state of the target beam or the polarization state of the optical signal is not specifically limited here. In addition, it needs to be further explained that the multi-stage phase modulators and between the phase modulators and the polarization beam splitter 304 and the polarization rotation combiner 306 will be connected through a 3dB coupler according to actual needs. The specific 3dB coupler The quantity is determined according to the actual scene and the number of phase modulators, and there is no specific quantity limit here. For example, in the scenario of two-stage phase modulators, the connections between the first phase modulator and the second phase modulator and between the second phase modulator and the polarization rotation combiner 306 can be connected through 3dB couplers.

As shown in Figure 4, the detection module 302 is used to obtain the first polarization state information and the second polarization state information of the target beam, the first polarization state information is the polarization information before the target beam enters the polarization control module, and the second polarization state information is The polarization information of the target beam after it exits the polarization control module.

The detection module 302 includes a first photoelectric conversion circuit 307 , a second photoelectric conversion circuit 308 , a first current-voltage conversion circuit 309 and a second current-voltage conversion circuit 310 .

The first photoelectric conversion circuit 307 is used to determine the first current according to the target beam before the incident polarization control module; specifically, the first photoelectric conversion circuit can include two photoelectric conversion units, and the photoelectric conversion unit A can be used to The polarized light in the first direction split by the target beam adjusted by the control module determines the corresponding first current A; the photoelectric conversion unit B can be used to split the polarized light in the second direction according to the target beam not adjusted by the polarization control module The corresponding first current B is determined.

The second photoelectric conversion circuit 308 is used to determine the second current according to the target light beam after exiting the polarization control module; The conversion unit C can be used to determine the corresponding second current A according to the polarized light in the second direction split by the target beam that has been adjusted by the polarization control module; the photoelectric conversion unit D can be used to The polarized light in the second direction split by the light beam determines the corresponding second current B. Any one of the above-mentioned photoelectric conversion units may be an electronic device such as a photodiode that can convert light signals and current signals.

The first current-voltage conversion circuit 309 is used to determine the first voltage according to the first current; specifically, the first current-voltage conversion circuit includes a current-voltage conversion unit A and a current-voltage conversion unit B, and the current-voltage conversion unit A is used for The above-mentioned first current A is converted into a first voltage A, and the current-voltage conversion unit B is used for converting the above-mentioned first current B into a first voltage B.

The second current-voltage conversion circuit 310 is used to determine the second voltage according to the second current. Specifically, the second current-voltage conversion circuit includes a current-voltage conversion unit C and a current-voltage conversion unit D. The current point-to-voltage conversion circuit unit C is used to convert the above-mentioned second current A into a second voltage A. The current voltage The conversion unit D is used for converting the above-mentioned second current B into a second voltage B.

In the embodiment of the present application, the above-mentioned polarization state information is the polarized light power of polarized light. In addition, the polarization state information may also be polarization state information such as the amplitude of polarized light, polarization direction, and type of polarized light. Do limited.

In the embodiment of the present application, the detection module includes a first photoelectric conversion circuit 307, a second photoelectric conversion circuit 308, a first current-voltage conversion circuit 309, and a second current-voltage conversion circuit 310; in addition, the detection module may also include other A circuit unit or circuit device that can convert an optical signal into an electrical signal, such as a photovoltage conversion circuit that can convert an optical signal into a voltage signal, or other devices that directly or indirectly obtain the polarization state information of the target beam and then convert it into an electrical signal device or equipment, which is not specifically limited here.

As shown in Figure 5, the control circuit module 303 is used to determine the target control voltage according to the first polarization state information and the second polarization state information of the target beam; the control circuit module includes a first analog-to-digital conversion circuit 311, a second analog-to-digital conversion circuit 312 , processor 313 and digital-to-analog conversion circuit 314 .

The above-mentioned first analog-to-digital conversion circuit 311 is used to determine the first polarized light power of the target beam before the incident polarization control module according to the first voltage; that is, to convert the analog signal of the first voltage into the digital signal of the first polarized light power, so that The processor adjusts the polarization state of the signal light accordingly. Specifically, the first analog-to-digital conversion circuit includes an analog-to-digital conversion unit A and an analog-to-digital conversion unit B, the analog-to-digital conversion unit A is used to determine the first polarized optical power A according to the above-mentioned first voltage A, and the analog-to-digital conversion unit B is used to determine the first polarized light power B according to the above-mentioned first voltage B.

The second analog-to-digital conversion circuit 312 is used to determine the second polarized light power of the target beam after exiting the polarization control module according to the second voltage; that is, to convert the analog signal of the second voltage into a digital signal of the second polarized light power for easy processing The device adjusts the polarization state of the signal light accordingly. Specifically, the second analog-to-digital conversion circuit includes an analog-to-digital conversion unit C and an analog-to-digital conversion unit D, the analog-to-digital conversion unit C is used to determine the second polarized light power A according to the second voltage A, and the analog-to-digital conversion unit D is used to determine the second polarized light power B according to the above second voltage B.

The processor 313 is used to determine the adjustment step according to the first polarized light power, the second polarized light power and the parameters of the polarization control module; The second polarized light power A, the second polarized light power B and the parameters of the polarization control module determine the adjustment step size.

In the embodiment of the present application, the processor determines the adjustment step size by determining the positive and negative values of the adjustment step size; it may also be to determine the numerical value of the adjustment step size; it may also be to determine the positive and negative values of the adjustment step size and The numerical value is not limited here.

The digital-to-analog conversion circuit 314 is used to determine the target control voltage according to the adjustment step and load the target control voltage to the polarization control unit. The digital-to-analog conversion circuit 314 changes the adjustment amount of the polarization control unit for the polarized light in the first direction and the polarized light in the second direction by changing the target control voltage applied by the digital-to-analog conversion circuit to the polarization control unit. Specifically, the digital-to-analog conversion circuit may include a digital-to-analog conversion unit A and a digital-to-analog conversion unit B, the digital-to-analog conversion unit A is used to determine the target control voltage A according to the adjustment step, and the digital-to-analog conversion unit B is used to determine The step size determines the target control voltage B.

In the embodiment of the present application, the first photoelectric conversion circuit includes two photoelectric conversion units, correspondingly, the first current-voltage conversion circuit includes two current-voltage conversion units, and the first analog-to-digital conversion circuit includes two analog-to-digital conversion units; In the embodiment of the application, the second photoelectric conversion circuit includes two photoelectric conversion units, correspondingly, the second current-voltage conversion circuit includes two current-voltage conversion units, and the second analog-to-digital conversion circuit includes two analog-to-digital conversion units; in addition In addition, the first photoelectric conversion circuit in the embodiment of the present application may also include one, three, four and five photoelectric conversion units. Correspondingly, the first current-voltage conversion circuit may also include one, three One, four, and five current-to-voltage conversion units, the first analog-to-digital conversion circuit may also include one, three, four, and five equal-number analog-to-digital conversion units; similarly, in the embodiment of the present application The second photoelectric conversion circuit can also include two, three, four and five photoelectric conversion units, and correspondingly, the second current-voltage conversion circuit can also include two, three, four and five There are an equal number of current-to-voltage conversion units, and the second analog-to-digital conversion circuit may also include two, three, four, and five equal numbers of analog-to-digital conversion units, which are not limited here.

As shown in Figure 6, in a possible implementation, the detection module can also include a multimode interference beam splitter 315; the multimode interference beam splitter is used to convert the first direction of the target beam after the exit polarization control module The polarized light in the second direction and the polarized light in the second direction are interfered to obtain a target interference beam; specifically, the target interference beam may include an interference beam A and an interference beam B.

Correspondingly, the second photoelectric conversion circuit is also used to determine the third current according to the interference beam; specifically, the second photoelectric conversion circuit further includes a photoelectric conversion unit E and a photoelectric conversion unit F, and the photoelectric conversion unit E is used to determine the third current according to the interference beam A determines the third current A, and the photoelectric conversion unit F is used to determine the third current B according to the interference beam B.

Correspondingly, the second current-voltage conversion circuit is also used to determine the third voltage according to the third current. Specifically, the second current-voltage conversion circuit further includes a current-voltage conversion circuit unit E and a current-voltage conversion circuit unit F, the current-current conversion circuit unit E is used to convert the above-mentioned third current A into a third voltage A, the The current-to-current conversion circuit unit F is used to convert the above-mentioned third current B into a third voltage B.

As shown in Figure 7, the second analog-to-digital conversion circuit is also used to determine the third polarized light power of the target beam after exiting the polarization control module according to the third voltage; specifically, the second analog-to-digital conversion circuit also includes an analog-to-digital conversion A unit E and an analog-to-digital conversion unit F, the analog-to-digital conversion unit E is used to determine the third polarized light power A according to the third voltage A, and the analog-to-digital conversion unit F is used to determine the third polarized light power B according to the third voltage B , and then determine the third polarized light power according to the third polarized light power A and the third polarized light power B.

The processor is configured to determine the adjustment step size according to the first polarized light power, the second polarized light power, the third polarized light power and the parameters of the polarization control module.

In the embodiment of the present application, the target interference beam may include two interference beams. In addition, the target interference beam may also include more than two interference beams. Correspondingly, the second photoelectric conversion circuit may also include two more than one photoelectric conversion unit, and the second current-voltage conversion circuit further includes two or more current-voltage conversion circuit units, which are not specifically limited here.

As shown in FIG. 8, in a possible implementation, compared with the optical polarization control device shown in FIG. 3, the control module of the optical polarization control device as shown in FIG. 8 does not include a polarization beam splitter and Instead, the polarization rotation combiner includes two polarization beam splitters in the polarization detection module; the detection module can obtain the corresponding polarized light in the first direction and the polarized light in the second direction through the two polarization beam splitters.

In the embodiment of the present application, the polarization control module includes a polarization beam splitter, a polarization control unit, and a polarization rotation combiner. In addition, the polarization control module may only include a polarization control unit, not including a polarization beam splitter and a polarization rotation The combiner, for example, in the case where the target light beam incident on the polarization control module includes polarized light in the first direction and polarized light in the second direction, the polarization control module only includes the polarization control unit, which is not limited here.

As shown in Figure 9, if the polarization control unit in the embodiment of the present application is a phase modulator, the voltage signal from the digital-to-analog conversion circuit can be loaded to one arm of the phase modulator, or can be loaded to the two arms of the phase modulator. The push-pull type, or the dobby loaded to the phase modulator, is specifically determined according to the specifications of the phase modulator, and is not limited in this embodiment of the application.

As shown in Figure 10, the embodiment of the present application provides a method for controlling the polarization state of light, which is applied to a device for controlling the state of polarization of light, and the device for controlling the state of light polarization includes: a detection module, a control circuit module and a polarization control module, The detection module first obtains the first polarization state information and the second polarization state information of the target beam, and then the control circuit module determines the target control voltage according to the first polarization state information and the second polarization state information of the target beam, and finally the polarization control module according to The target control voltage adjusts the polarization state of the target beam.

As shown in FIG. 11, an embodiment of the present invention provides a method for controlling the state of polarization of light, and the method is applied to a device for controlling the state of light polarization. The device for controlling the state of light polarization includes the following modules, units, and circuits. Be explained:

1101. The polarization beam splitter splits the target beam into polarized light in a first direction and polarized light in a second direction.

The polarization beam splitter divides the target beam before entering the polarization control module into the polarized light in the first direction and the polarized light in the second direction, that is, the target beam that has not been adjusted by the polarization control unit is divided into the polarized light in the first direction and the polarized light in the second direction. direction of polarized light, the first direction and the second direction are perpendicular to each other and perpendicular to the transmission direction of the target light beam.

1102. The first photoelectric conversion circuit determines a first current, and the second photoelectric conversion circuit determines a second current.

The first photoelectric conversion circuit determines the first current according to the target light beam before the incident polarization control module; specifically, the first photoelectric conversion circuit may include two photoelectric conversion units, and the photoelectric conversion unit A is based on the above-mentioned target beam that has not been adjusted by the polarization control module. The polarized light in the first direction split by the light beam determines the corresponding first current A; the photoelectric conversion unit B determines the corresponding first current based on the polarized light in the second direction split by the target beam that has not been adjusted by the polarization control module b.

The second photoelectric conversion circuit determines the second current according to the target light beam after exiting the polarization control module; The corresponding second current A is determined according to the polarized light in the second direction of the target beam that has been adjusted by the polarization control module; the photoelectric conversion unit D is based on the second direction of the target beam that has not been adjusted by the polarization control module. The polarized light determines the corresponding second current B. Any one of the above-mentioned photoelectric conversion units may be an electronic device such as a photodiode that can convert light signals and current signals.

1103. The first current-voltage conversion circuit determines the first voltage, and the second current-voltage conversion circuit determines the second voltage.

The first current-voltage conversion circuit determines the first voltage according to the first current; specifically, the first current-voltage conversion circuit includes a current-voltage conversion unit A and a current-voltage conversion unit B, and the current-voltage conversion unit A converts the first current to A is converted into a first voltage A, and the current-voltage conversion unit B converts the above-mentioned first current B into a first voltage B.

The second current-voltage conversion circuit determines a second voltage according to the second current. Specifically, the second current-voltage conversion circuit includes a current-voltage conversion unit C and a current-voltage conversion unit D. The current point-to-voltage conversion circuit unit C converts the second current A into a second voltage A. The current-voltage conversion unit D converts the aforementioned second current B into a second voltage B.

In the embodiment of the present application, the optical signal is converted into an electrical signal through the first photoelectric conversion circuit, the second photoelectric conversion circuit, the first current-voltage conversion circuit, and the second current-voltage conversion circuit, or other methods that convert the optical signal into a voltage The photoelectric voltage conversion circuit of the signal may also be other devices or devices that directly or indirectly obtain the polarization state information of the target beam and then convert it into an electrical signal, which is not limited here.

1104. The first analog-to-digital conversion circuit determines the first polarized light power, and the second analog-to-digital conversion circuit determines the second polarized light power.

The first analog-to-digital conversion circuit determines the first polarized light power of the target beam before the incident polarization control module according to the first voltage; that is, converts the analog signal of the first voltage into the digital signal of the first polarized light power, so that the processor can use it accordingly Adjust the polarization state of the signal light. Specifically, the first analog-to-digital conversion circuit includes an analog-to-digital conversion unit A and an analog-to-digital conversion unit B, the analog-to-digital conversion unit A determines the first polarized optical power A according to the first voltage A, and the analog-to-digital conversion unit B determines the first polarized optical power A according to the The above-mentioned first voltage B determines the first polarized light power B.

The second analog-to-digital conversion circuit determines the second polarized light power of the target beam after exiting the polarization control module according to the second voltage; that is, converts the analog signal of the second voltage into a digital signal of the second polarized light power, so that the processor can use it accordingly Adjust the polarization state of the signal light. Specifically, the second analog-to-digital conversion circuit includes an analog-to-digital conversion unit C and an analog-to-digital conversion unit D, the analog-to-digital conversion unit C determines the second polarized optical power A according to the second voltage A, and the analog-to-digital conversion unit D determines the second polarized light power A according to The above-mentioned second voltage B determines the second polarized light power B.

1105. The processor determines the adjustment step size.

The processor determines the adjustment step according to the first polarized light power, the second polarized light power and the parameters of the polarization control module according to the corresponding determination mechanism; , the second polarized light power A, the second polarized light power B and the parameters of the polarization control module determine the adjustment step size.

In the embodiment of the present application, the processor may determine the adjustment step size by determining the positive and negative values of the adjustment step size, for example, according to the difference between the first polarized light power minus the second polarized light power and the parameters of the polarization control module. Adjust the positive and negative values of the step size. If the difference between the first polarized light power minus the second polarized light power is positive, the adjustment step is determined to be a positive value. If the first polarized light power minus the second polarized light power If the difference is negative, then it is determined that the adjustment step is a negative value, and the size of the step value is fixed; it can also determine the value of the adjustment step, such as subtracting the second polarized light from the power of the first polarized light The difference in power and the parameters of the polarization control module determine the value of the adjustment step; the positive and negative values and value of the adjustment step can also be determined, which is not specifically limited here.

As shown in Figure 12, the optical polarization state control device first determines the positive or negative of the adjustment step according to the first polarization power, the second polarization power and the parameters of the polarization control module, and then determines the value of the adjustment step, and then The control parameters related to the phase modulator are updated according to the adjustment step, and finally the optical polarization state control device adjusts the phase modulator according to the first polarized light power, the second polarized light power and the control parameters related to the phase modulator. Specifically, steps a to e are as follows:

Step a: The light polarization state control device determines the first polarized light power and the second polarized light power.

Step b: The light polarization state control device determines whether the direction of the step size is a negative direction according to the commutation strategy. The direction is negative; if the light polarization state control device determines that the power of the first polarized light is greater than the power of the second polarized light, it can determine that the direction of the adjustment step is positive.

Step c: the light polarization state control device calculates the size of the adjustment step according to the first polarization state power and the second polarization state power. For example, the optical polarization state control device may multiply the difference between the power of the first polarization state and the power of the second polarization state by a corresponding coefficient to determine the size of the adjustment step.

Step d: The light polarization state control device updates the control parameters related to the phase modulator according to the positive and negative directions of the size of the adjustment step.

Step e: the light polarization state control device adjusts the phase modulator according to the first polarized light power, the second polarized light power and the updated control parameters related to the phase modulator, thereby adjusting the polarization state of the target light beam.

1106. The digital-to-analog conversion circuit determines the target control voltage.

The digital-to-analog conversion circuit determines the target control voltage according to the adjustment step size. Specifically, the digital-to-analog conversion circuit may include a digital-to-analog conversion unit A and a digital-to-analog conversion unit B, the digital-to-analog conversion unit A determines the target control voltage A according to the adjustment step size, and the digital-to-analog conversion unit B determines the target control voltage A according to the adjustment step size control voltage B.

1107. The polarization control unit adjusts the polarization state of the target beam according to the target control voltage.

The polarization control unit is used to adjust the polarization state of the polarized light in the first direction and the polarized light in the second direction according to the target control voltage, and the control circuit module loads the target control voltage on the polarization control unit 305 with the polarization control unit for the first The adjustment amount of the polarization state of the polarized light in the first direction is related to the polarization state of the polarized light in the second direction. Specifically, the polarization control unit adjusts the polarized light power of the polarized light in the first direction and the polarized light power of the polarized light in the second direction to be equal, so that the target beam can normally load the corresponding information without a The power of the signal light in the direction is zero, which makes it impossible to beat the signal light, that is, there will be no situation where the target beam cannot carry the loaded information; the above-mentioned target beam includes Local Oscillation (LO), and the local oscillator light without any information The corresponding information can be loaded by modulation.

Specifically, the polarization control unit may include a secondary phase modulator, the secondary phase modulator includes a first phase modulator and a second phase modulator, the first phase modulator adjusts the target beam according to the target control voltage , the second phase modulator adjusts the target beam exiting the first phase modulator according to the target control voltage. That is, the first phase modulator and the second phase modulator can form a two-stage phase modulator, and the target beam incident on the polarization control unit is first adjusted by the first phase modulator and then by the second phase modulator, so that The polarization control unit adjusts the polarization state of the target beam.

Specifically, the adjustment amount of the polarization state of the polarization control unit for the polarized light in the first direction and the polarized light in the second direction is related to the target control voltage, that is, the control circuit module is loaded on the polarization control unit by changing the control circuit module. The target control voltage is used to change the adjustment amount of the polarization control unit for the polarized light in the first direction and the polarized light in the second direction.

In the embodiment of the present application, the polarization control unit includes a two-stage phase modulator. In addition, the polarization control unit can also be a phase modulator, a multi-level phase modulator including more than two phase modulators, or a niobium phase modulator. A device such as a 1/2 wave plate of lithium acid material that can adjust the polarization state of the target beam or the polarization state of the optical signal is not specifically limited here.

1108. The polarization rotation combiner combines the polarized light in the first direction and the polarized light in the second direction into a target beam.

The polarization rotation combiner combines the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control module into the target beam, that is, combines the polarized light in the first direction and the polarized light in the second direction that have been adjusted by the polarization control unit is the target beam, the first direction and the second direction are consistent with the first direction and the second direction of the above-mentioned polarizing beam splitter 304 .

In a possible implementation, when the polarization control module includes a polarization beam splitter 304 and a polarization control unit 305, but does not include a polarization rotation combiner, for example, when the polarization control module works with an integrated coherent receiver, the polarization control module The polarization rotation combiner may not be included, therefore, step 1108 may not be performed, which is not specifically limited here.

In a possible implementation manner, the detection module may also include a multimode interference beam splitter; the multimode interference beam splitter combines the polarized light in the first direction and the polarized light in the second direction of the target beam after exiting the polarization control module. The polarized light obtains a target interference beam through interference; the target interference beam may include an interference beam A and an interference beam B.

Correspondingly, the second photoelectric conversion circuit also determines the third current according to the interference beam; specifically, the second photoelectric conversion circuit further includes a photoelectric conversion unit E and a photoelectric conversion unit F, the photoelectric conversion unit E determines the third A current A, the photoelectric conversion unit F determines a third current B according to the interference beam B.

Correspondingly, the second current-voltage conversion circuit also determines the third voltage according to the third current. Specifically, the second current-voltage conversion circuit further includes a current-voltage conversion circuit unit E and a current-voltage conversion circuit unit F. The current-current conversion circuit unit E converts the above-mentioned third current A into a third voltage A. The current The conversion circuit unit F converts the third current B into a third voltage B. The second analog-to-digital conversion circuit also determines the third polarized light power of the target beam after exiting the polarization control module according to the third voltage; specifically, the second analog-to-digital conversion circuit also includes an analog-to-digital conversion unit E and an analog-to-digital conversion unit F , the analog-to-digital conversion unit E determines the third polarized light power A according to the third voltage A, the analog-to-digital conversion unit F determines the third polarized light power B according to the third voltage B, and then according to the third polarized light power A and the third The polarized light power B determines the third polarized light power. Finally, the processor determines the adjustment step size according to the first polarized light power, the second polarized light power, the third polarized light power and the parameters of the polarization control module.

The method for controlling the polarization state of light in the embodiment of the present application may be implemented by the device for controlling the polarization state of light shown in FIG. 3 , and details are not described here again.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), magnetic disk or optical disc, etc., which can store program codes. .

Claims

A light polarization state control device, characterized in that the light polarization state control device includes: a detection module, a control circuit module, and a polarization control module;

The detection module is used to obtain the first polarization state information and the second polarization state information of the target beam, the first polarization state information is the polarization information before the target beam enters the polarization control module, and the second polarization state information is the polarization information after the target beam exits the polarization control module;

The control circuit module is used to determine a target control voltage according to the first polarization state information and the second polarization state information of the target light beam;

The polarization control module is used for adjusting the polarization state of the target beam according to the target control voltage.
The light polarization state control device according to claim 1, wherein the polarization control module comprises a polarization beam splitter, a polarization rotation combiner and a polarization control unit;

The polarization beam splitter is used to divide the target beam before entering the polarization control unit into polarized light in a first direction and polarized light in a second direction, and the first direction and the second direction are perpendicular to each other;

The polarization control unit is configured to adjust the polarization states of the polarized light in the first direction and the polarized light in the second direction;

The polarization rotation combiner is used to combine the polarized light in the first direction and the polarized light in the second direction after exiting the polarization control unit into a target beam.
The optical polarization state control device according to claim 2, wherein the detection module comprises a first photoelectric conversion circuit, a second photoelectric conversion circuit, a first current-voltage conversion circuit and a second current-voltage conversion circuit;

The first photoelectric conversion circuit is used to determine a first current;

The second photoelectric conversion circuit is used to determine a second current;

The first current-voltage conversion circuit is used to determine a first voltage according to the first current;

The second current-voltage conversion circuit is used to determine a second voltage according to the second current.
The optical polarization state control device according to claim 3, wherein the control circuit module comprises a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a digital-to-analog conversion circuit and a processor;

The first analog-to-digital conversion circuit is used to determine the first polarized light power of the target beam before the incident polarization control module;

The second analog-to-digital conversion circuit is used to determine the second polarized light power of the target beam after the outgoing polarization control module;

The processor is configured to determine an adjustment step according to the first polarized light power, the second polarized light power, and parameters of the polarization control module;

The digital-to-analog conversion circuit is used to determine the target control voltage according to the adjustment step size.
The optical polarization state control device according to claim 4, wherein the detection module further comprises a multimode interference beam splitter;

The multimode interference beam splitter is used to obtain an interference beam by interfering the polarized light in the first direction and the polarized light in the second direction of the target beam after the outgoing polarization control module;

The second photoelectric conversion circuit is also used to determine a third current according to the interference beam;

The second current-voltage conversion circuit is also used to determine a third voltage according to the third current.
The light polarization state control device according to claim 5, wherein the second analog-to-digital conversion circuit is also used to determine the third polarized light of the target beam after the outgoing polarization control module according to the third voltage power;

The processor is configured to determine an adjustment step according to the first polarized light power, the second polarized light power, the third polarized light power and parameters of the polarization control module.
The optical polarization control device according to claim 6, wherein the polarization control unit is configured to adjust the power of the polarized light in the first direction and the polarized light in the second direction according to the target control voltage The powers are equal, the adjustment amount of the polarization control unit to the polarized light in the first direction and the polarized light in the second direction is related to the target control voltage, and the first direction and the second direction are perpendicular to each other.
The optical polarization state control device according to any one of claims 1 to 7, wherein the polarization control unit includes a secondary phase modulator, and the secondary phase modulator includes a first phase modulator and a second phase modulator. Two phase modulators, the first phase modulator is used to adjust the polarized light in the first direction and the polarized light in the second direction according to the target control voltage, and the second phase modulator is used to adjust the polarized light in the second direction according to the target The control voltage adjusts the polarized light in the first direction and the polarized light in the second direction exiting the first phase modulator.
A method for controlling the state of polarization of light, characterized in that it is applied to a device for controlling the state of light polarization, and the device for controlling the state of light polarization includes a detection module, a control circuit module, and a polarization control module, and the method includes:

Obtain the first polarization state information and the second polarization state information of the target beam through the detection module, the first polarization state information is the polarization information before the target beam enters the polarization control module, and the second polarization state information is Polarization information of the target beam after exiting the polarization control module;

determining a target control voltage according to the first polarization state information and the second polarization state information of the target light beam through the control circuit module;

The polarization state of the target light beam is adjusted by the polarization control module according to the target control voltage.
The method according to claim 9, wherein the polarization control module comprises a polarization beam splitter, a polarization rotation combiner and a polarization control unit;

dividing the target beam before the incident polarization control unit into polarized light in a first direction and polarized light in a second direction through the polarization beam splitter, the first direction and the second direction are perpendicular to each other;

The polarized light in the first direction and the polarized light in the second direction are adjusted by the polarization control unit, and the adjustment amount of the polarized light in the first direction and the polarized light in the second direction by the polarization control unit is the same as The target control voltage is related;

The polarized light in the first direction and the polarized light in the second direction after exiting the polarization control unit are combined into a target beam by the polarization rotation combiner.
The method according to claim 10, wherein the detection module comprises a first photoelectric conversion circuit, a second photoelectric conversion circuit, a first current-voltage conversion circuit and a second current-voltage conversion circuit, and the The module acquires the first polarization state information and the second polarization state information of the target beam, including:

determining a first current through the first photoelectric conversion circuit according to the target beam before the incident polarization control module;

determining a second current through the second photoelectric conversion circuit according to the target light beam after the outgoing polarization control module;

determining a first voltage according to the first current through the first current-voltage conversion circuit;

A second voltage is determined according to the second current by the second current-voltage conversion circuit.
The method according to claim 11, wherein the control circuit module includes a first analog-to-digital conversion circuit, a second analog-to-digital conversion circuit, a digital-to-analog conversion circuit, and a processor, and the control circuit module according to The first polarization state information and the second polarization state information of the target light beam determine the target control voltage, including:

The first analog-to-digital conversion circuit is used to determine the first polarized light power of the target beam before the incident polarization control module according to the first voltage;

The second analog-to-digital conversion circuit is used to determine the second polarized light power of the target beam after the outgoing polarization control module according to the second voltage;

The processor is configured to determine an adjustment step according to the first polarized light power, the second polarized light power, and parameters of the polarization control module;

The digital-to-analog conversion circuit is used to determine the target control voltage according to the adjustment step size.
The method according to claim 12, wherein the detection module further comprises a multimode interference beam splitter, and the method further comprises:

Obtaining an interference beam by interfering the polarized light in the first direction and the polarized light in the second direction of the target beam after the outgoing polarization control module through the multimode interference beam splitter;

determining a third current according to the interference beam through the second photoelectric conversion circuit;

A third voltage is determined according to the third current through the second current-voltage conversion circuit.
The method according to claim 13, further comprising:

determining the third polarized light power of the target beam after the outgoing polarization control module according to the third voltage through the second analog-to-digital conversion circuit;

An adjustment step size is determined by the processor according to the first polarized light power, the second polarized light power, the third polarized light power and parameters of the polarization control module.
The method according to claim 14, wherein the adjusting the polarization state of the target beam by the polarization control unit comprises:

The power of the polarized light in the first direction of the target beam is adjusted to be equal to the power of the polarized light in the second direction by the polarization control unit, and the first direction and the second direction are perpendicular to each other.
The method according to any one of claims 9 to 15, wherein the polarization control unit includes a secondary phase modulator, and the secondary phase modulator includes a first phase modulator and a second phase modulator , the adjusting the polarization state of the target beam through the polarization control unit includes:

The polarized light in the first direction and the polarized light in the second direction are adjusted by the first phase modulator, and the first direction exiting the first phase modulator is adjusted by the second phase modulator polarized light and polarized light in the second direction.