Adaptive polarization state control system

Abstract

The invention provides a self-adaptive polarization state control system, relates to the technical field of laser communication, and is used for improving the technical problems that circularly polarized light is possibly converted into elliptically polarized light due to the posture change of equipment, and the signal quality and stability are influenced in the related technology. The control system comprises a receiving and transmitting common module which is used for receiving or transmitting laser and comprises an adjusting assembly used for adjusting the direction of a light beam; the polarization state detection module is used for detecting the polarization state of the laser emitted by the receiving and transmitting common module; the transmitting light path is used for generating first polarized light, adjusting the first polarized light into second polarized light and transmitting the second polarized light to the receiving and transmitting common module, and comprises a first polarization state control module which is used for adjusting the first polarized light into the second polarized light and transmitting the second polarized light to the receiving and transmitting common module; the control module is used for controlling the first polarization state control module to adjust the polarization state of the first polarized light according to the state of the adjusting assembly and the polarization state of the laser emitted by the receiving and transmitting common module.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser communication technology, and in particular to an adaptive polarization state control system. Background Art

[0002] With the development of modern communication technology, laser communication, as a high-speed, long-distance communication method, is increasingly widely used. In laser communication systems, the polarization state of optical signals has a decisive influence on the transmission quality of signals. The stability of the polarization state is directly related to the fidelity of the signal and the demodulation capability of the receiving end.

[0003] In incoherent detection systems, due to the lack of control over the polarization state of light waves, the signal is easily affected by changes in the external environment, such as temperature, humidity, atmospheric pressure, etc. These factors may cause the instability of the polarization state of light waves, thereby affecting the transmission quality of the signal. Coherent detection technology achieves high-precision detection of signals by using a local oscillator to interfere with the received signal. This technology can effectively improve the signal isolation of the communication system, reduce noise interference, and enhance the detection sensitivity of the signal.

[0004] However, the linearly polarized light used in coherent detection systems is very sensitive to changes in the external environment, especially in the atmosphere, where temperature and pressure fluctuations may cause the polarization state of the light wave to change, thus affecting the reliability of the signal. Although the depolarization effect of circularly polarized light is small in the atmosphere, in laser communication systems, changes in the device's posture, such as pitch and azimuth rotation, may still cause circularly polarized light to convert into elliptically polarized light. This phenomenon will reduce the signal quality and system stability.

[0005] In laser communication systems, it is difficult to achieve a perfect zero phase difference on the lens coating, which further increases the difficulty of maintaining the circular polarization state. Therefore, a device that can monitor and adjust the laser polarization state in real time is needed to ensure that the output laser always maintains a circular polarization state under various attitude changes, thereby improving the overall performance and reliability of the laser communication system. Summary of the invention

[0006] The embodiment of the present application provides an adaptive polarization state control system for improving the technical problem in related technologies that circularly polarized light may be converted into elliptically polarized light due to changes in the posture of the device, thereby affecting signal quality and stability.

[0007] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0008] The embodiment of the present application provides an adaptive polarization state control system, the control system comprising: a transceiver common module, the transceiver common module is used to receive and transmit laser, the transceiver common module comprises an adjustment component for adjusting the direction of the light beam; a polarization state detection module is used to detect the polarization state of the laser emitted by the transceiver common module;

[0009] An emission optical path, the emission optical path is used to generate a first polarized light, and adjust the first polarized light to a second polarized light before transmitting to the transceiver shared module, including a first polarization state control module, the first polarization state control module is used to adjust the first polarized light to the second polarized light;

[0010] A control module is used to control the first polarization state control module to adjust the polarization state of the first polarized light according to the state of the adjustment component and the polarization state of the laser emitted by the transmitting and receiving shared module.

[0011] In some embodiments, the control system further includes a receiving optical path, which is used to receive first polarized light. The first polarization state control module is also used to convert the laser received by the transceiver sharing module into the first polarized light and transmit it to the receiving optical path.

[0012] In some embodiments, the receiving optical path further includes a second polarization state control module, the second polarization state control module is used to adjust the laser transmitted to the receiving optical path to the first polarized light, and the polarization state detection module is also used to detect the polarization state of the first polarized light converted by the second polarization state control module;

[0013] The control module is further used to control the second polarization state control module to adjust the polarization state of the laser transmitted to the receiving optical path according to the state of the adjustment component and the polarization state of the first polarized light converted by the second polarization state control module.

[0014] In some embodiments, the adjustment component includes a pitch rotation component and an azimuth rotation component, the pitch rotation component is used to adjust the pitch angle of the second polarized light, and the azimuth rotation component is used to adjust the azimuth angle of the second polarized light. The control module controls the first polarization state control module to adjust the polarization state of the first polarized light according to the pitch angle, the azimuth angle and the polarization state of the laser emitted by the transceiver shared module.

[0015] In some embodiments, the control system includes a plurality of sensors for detecting a pitch angle of the pitch rotation assembly and an azimuth angle of the azimuth rotation assembly.

[0016] In some embodiments, the polarization state detection module includes a first beam splitter and a first polarization state detection unit, the first beam splitter is used to transmit the second polarized light adjusted by the adjustment component and separate a first proportion of the light beam to the first polarization state detection unit, the first polarization state detection unit is used to detect the polarization state of the light beam separated by the first beam splitter and transmit it to the control module.

[0017] In some embodiments, the polarization state detection module also includes a second beam splitter and a second polarization state detection unit, the second beam splitter is used to transmit the light beam output by the second polarization state control module and split a second proportion of the light beam to the second polarization state detection unit, the second polarization state detection unit is used to detect the polarization state of the light beam split by the second beam splitter and transmit it to the control module.

[0018] In some embodiments, the emission light path further includes an emission lens and a polarization beam splitter prism, wherein the emission lens is used to generate a first polarized light, and the polarization beam splitter prism is used to suppress lasers of other polarization states generated by the emission lens and only allow the first polarized light to enter the subsequent light path.

[0019] In some embodiments, the transmitting optical path also includes a reflector, and the transmit-receive shared module also includes a telescope and a polarization beam splitter, the reflector is used to reflect the first polarized light output by the polarization beam splitter to the polarization beam splitter, the polarization beam splitter is used to reflect the first polarized light reflected by the reflector to the first polarization state control module, and the telescope is used to receive the second polarized light generated by the first polarization state control module and transmit it.

[0020] In some embodiments, the first polarization state control module includes one of an electro-optic modulator, a polarizer, and a liquid crystal polarization controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a control system provided for some embodiments of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0023] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0024] In addition, in the present application, directional terms such as "up", "down", "left" and "right" may be defined including but not limited to the orientation relative to the schematic placement of the components in the drawings. It should be understood that these directional terms may be relative concepts, which are used for relative description and clarification, and may change accordingly according to the change in the orientation of the components in the drawings.

[0025] In this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. In addition, the term "electrical connection" can be a way of achieving electrical connection for signal transmission.

[0026] As used herein, “about,” “substantially,” or “approximately” includes the stated value and reference values ​​that are within an acceptable range of deviation from the particular value, where the acceptable range of deviation is as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0027] In the embodiments of the present application, the words "exemplarily" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplarily" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0028] With the development of modern communication technology, laser communication, as a high-speed, long-distance communication method, is increasingly widely used. In laser communication systems, the polarization state of optical signals has a decisive influence on the transmission quality of signals. The stability of the polarization state is directly related to the fidelity of the signal and the demodulation capability of the receiving end.

[0029] In incoherent detection systems, due to the lack of control over the polarization state of light waves, the signal is easily affected by changes in the external environment, such as temperature, humidity, atmospheric pressure, etc. These factors may cause the instability of the polarization state of light waves, thereby affecting the transmission quality of the signal. Coherent detection technology achieves high-precision detection of signals by using a local oscillator to interfere with the received signal. This technology can effectively improve the signal isolation of the communication system, reduce noise interference, and enhance the detection sensitivity of the signal.

[0030] However, the linearly polarized light used in coherent detection systems is very sensitive to changes in the external environment, especially in the atmosphere, where temperature and pressure fluctuations may cause the polarization state of the light wave to change, thus affecting the reliability of the signal. Although the depolarization effect of circularly polarized light is small in the atmosphere, in laser communication systems, changes in the device's posture, such as pitch and azimuth rotation, may still cause circularly polarized light to convert into elliptically polarized light. This phenomenon will reduce the signal quality and system stability.

[0031] In laser communication systems, it is difficult to achieve a perfect zero phase difference on the lens coating, which further increases the difficulty of maintaining the circular polarization state. Therefore, a device that can monitor and adjust the laser polarization state in real time is needed to ensure that the output laser always maintains a circular polarization state under various attitude changes, thereby improving the overall performance and reliability of the laser communication system.

[0032] In summary, the present invention aims to provide a new type of polarization state adjustment device, which can dynamically adjust the polarization state of the laser according to the pitch and azimuth rotation in the laser communication system, ensuring that the output laser signal can maintain a stable circular polarization state even in a dynamically changing environment, thereby optimizing the signal transmission quality and enhancing the stability and anti-interference capability of the communication system.

[0033] An embodiment of the present application provides an adaptive polarization state control system, which includes a transmitting and receiving shared module, a polarization state detection module, a transmitting optical path, a receiving optical path, and a control module.

[0034] The transmitting optical path is used to generate first polarized light and transmit the first polarized light to the transmitting and receiving shared module.

[0035] Exemplarily, the emission optical path includes a first polarization state control module 5, an emission lens 1, and a polarization beam splitter prism 2. The emission lens 1 is used to generate a first polarized light, the polarization beam splitter prism 2 is used to suppress lasers of other polarization states generated by the emission lens 1, and only allow the first polarized light to enter the subsequent optical path, and the first polarization state control module 5 is used to convert the first polarized light into the second polarized light, or convert the second polarized light into the first polarized light. In the embodiment of the present application, the second polarized light is circularly polarized light, including right-handed circularly polarized light and left-handed circularly polarized light; the first polarized light is linearly polarized light, wherein the linear polarized light includes horizontally polarized light and vertically polarized light.

[0036] Since the first polarized light generated by the transmitting lens 1 is not completely vertically or horizontally polarized light, it may cause unstable signal quality, etc. Therefore, it is necessary to filter the first polarized light generated by the transmitting lens 1. In the embodiment of the present application, by adding a polarization beam splitter prism 2 between the transmitting lens 1 and the first polarization state control module 5, the first polarized light generated by the transmitting lens 1 is processed to form vertically polarized light or horizontally polarized light.

[0037] In some examples, the first polarization state control module 5 includes one of an electro-optic modulator, a polarizer, and a liquid crystal polarization controller. Of course, the first polarization state control module 5 can also be implemented by a magneto-optic modulator, an acousto-optic modulator, a polarization beam splitter, and an integrated control system based on FPGA.

[0038] In some embodiments, the transmitting optical path further comprises a reflector 3. The transmitting and receiving shared module is used for receiving and transmitting lasers, and the transmitting and receiving shared module comprises an adjustment component, a telescope 6 and a polarization beam splitter 4.

[0039] The reflector 3 is used to reflect the first polarized light output by the polarization beam splitter 2 to the polarization beam splitter 4. The polarization beam splitter 4 is used to reflect the first polarized light reflected by the reflector 3 to the first polarization state control module 5 and transmit the light beam other than the first polarized light. The telescope 6 is used to receive the second polarized light generated by the first polarization state control module 5 and transmit it.

[0040] Exemplarily, the polarization beam splitter 4 may be a polarizing plate beam splitter.

[0041] In some embodiments, the adjustment component includes a pitch rotation component 7 and an azimuth rotation component 8, wherein the pitch rotation component 7 is used to adjust the pitch angle of the laser beam, such as the first polarized light and the second polarized light, and the azimuth rotation component 8 is used to adjust the azimuth angle of the laser beam.

[0042] In some embodiments, the control system includes a plurality of sensors, and the sensors are used to detect the pitch angle of the pitch rotation assembly 7 and the azimuth angle of the azimuth rotation assembly 8 and transmit the detection results to a control module.

[0043] In some embodiments, the control system further includes a receiving optical path, the receiving optical path is used to receive the first polarized light, and the first polarization state control module 5 is also used to convert the laser received by the transceiver sharing module into the first polarized light and transmit it to the receiving optical path. The receiving optical path includes a tracking camera assembly 15, a third beam splitter 14 and a receiving lens 16. The third beam splitter 14 transmits the first polarized light transmitted by the first polarization state control module 5 and divides a certain ratio, such as 10%, to the tracking camera assembly 15.

[0044] In some embodiments, the receiving optical path further includes a second polarization state control module 11, and the second polarization state control module 11 is used to further adjust the laser transmitted by the first polarization state control module 5 into the first polarized light.

[0045] Exemplarily, the second polarization state control module 11 may include one of an electro-optic modulator, a polarizer, and a liquid crystal polarization controller. Of course, the first polarization state control module 5 may also be implemented by a magneto-optic modulator, an acousto-optic modulator, a polarization beam splitter, and an integrated control system based on FPGA.

[0046] The polarization state detection module is used to detect the polarization state of the laser emitted by the transmitting and receiving shared module. The polarization state detection module is also used to detect the polarization state of the polarized light converted by the second polarization state control module 11 .

[0047] The polarization state detection module includes a first beam splitter 9 and a first polarization state detection unit 10. The first beam splitter 9 is used to transmit the second polarized light adjusted by the adjustment component and separate a first proportion, such as 1%, of the light beam to the first polarization state detection unit 10. The first polarization state detection unit 10 is used to detect the polarization state of the light beam separated by the first beam splitter 9 and transmit it to the control module.

[0048] In some embodiments, the polarization state detection module also includes a second beam splitter 12 and a second polarization state detection unit 13, the second beam splitter 12 is used to transmit the light beam output by the second polarization state control module 11 and separate a second proportion, such as 1% of the light beam to the second polarization state detection unit 13, and the second polarization state detection unit 10 is used to detect the polarization state of the light beam separated by the second beam splitter 12 and transmit it to the control module.

[0049] The control module controls the first polarization state control module 5 to adjust the polarization state of the first polarized light according to the pitch angle, the azimuth angle and the polarization state of the laser emitted by the transceiver shared module. The control module is also used to control the second polarization state control module 11 to adjust the polarization state of the first polarized light according to the pitch angle, the azimuth angle and the polarization state of the second polarized light.

[0050] Exemplarily, the control unit includes a microprocessor and a memory. The processor is used to execute a control algorithm. The memory is used to store a control algorithm and polarization state adjustment parameters. For example, the memory stores an algorithm for controlling the first polarization state control module 5 to adjust the polarization state of the second polarized light according to the pitch angle, the azimuth angle, and the polarization state of the laser emitted by the transceiver shared module. When the pitch rotation component 7 and the azimuth rotation component 8 rotate, a command for controlling the first polarization state control module 5 is generated to make the first polarization state control module 5 adjust the polarization state of the output laser, so that the laser output when the pitch rotation component 7 and the azimuth rotation component 8 rotate is also the second polarized light, avoiding the influence of the pitch rotation component 7 and the azimuth rotation component 8 on the second polarized light when rotating.

[0051] Through the description of the above implementation methods, technicians in the relevant field can clearly understand that the diagnostic method in the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the relevant technology, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention.

[0052] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0053] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0054] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0055] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated units may be implemented in the form of hardware.

[0056] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An adaptive polarization state control system, characterized in that: The control system comprises: A transceiver common module, the transceiver common module is used to receive and transmit lasers, and the transceiver common module includes an adjustment component for adjusting the direction of the light beam; A polarization state detection module, used to detect the polarization state of the laser emitted by the transmitting and receiving shared module; An emission optical path, the emission optical path is used to generate a first polarized light, and adjust the first polarized light to a second polarized light before transmitting to the transceiver shared module, including a first polarization state control module, the first polarization state control module is used to adjust the first polarized light to the second polarized light; A control module is used to control the first polarization state control module to adjust the polarization state of the first polarized light according to the state of the adjustment component and the polarization state of the laser emitted by the transmitting and receiving shared module.

2. The adaptive polarization state control system according to claim 1, characterized in that: The control system also includes a receiving optical path, which is used to receive the first polarized light. The first polarization state control module is also used to convert the laser received by the transceiver sharing module into the first polarized light and transmit it to the receiving optical path.

3. The adaptive polarization state control system according to claim 2, characterized in that: The receiving optical path further includes a second polarization state control module, the second polarization state control module is used to adjust the laser transmitted to the receiving optical path to the first polarized light, and the polarization state detection module is also used to detect the polarization state of the first polarized light converted by the second polarization state control module; The control module is further used to control the second polarization state control module to adjust the polarization state of the laser transmitted to the receiving optical path according to the state of the adjustment component and the polarization state of the first polarized light converted by the second polarization state control module.

4. The adaptive polarization state control system according to claim 3, characterized in that: The adjustment component includes a pitch rotation component and an azimuth rotation component, the pitch rotation component is used to adjust the pitch angle of the second polarized light, and the azimuth rotation component is used to adjust the azimuth angle of the second polarized light. The control module controls the first polarization state control module to adjust the polarization state of the first polarized light according to the pitch angle, the azimuth angle and the polarization state of the laser emitted by the transceiver shared module.

5. The adaptive polarization state control system according to claim 4, characterized in that: The control system includes a plurality of sensors, and the sensors are used to detect the pitch angle of the pitch rotation assembly and the azimuth angle of the azimuth rotation assembly.

6. The adaptive polarization state control system according to claim 4, characterized in that: The polarization state detection module includes a first beam splitter and a first polarization state detection unit. The first beam splitter is used to transmit the second polarized light adjusted by the adjustment component and separate a first proportion of the light beam to the first polarization state detection unit. The first polarization state detection unit is used to detect the polarization state of the light beam separated by the first beam splitter and transmit it to the control module.

7. The adaptive polarization state control system according to claim 6, characterized in that: The polarization state detection module also includes a second beam splitter and a second polarization state detection unit. The second beam splitter is used to transmit the light beam output by the second polarization state control module and split a second proportion of the light beam to the second polarization state detection unit. The second polarization state detection unit is used to detect the polarization state of the light beam split by the second beam splitter and transmit it to the control module.

8. The adaptive polarization state control system according to claim 1, characterized in that: The emission optical path also includes an emission lens and a polarization beam splitter prism. The emission lens is used to generate a first polarized light, and the polarization beam splitter prism is used to suppress lasers of other polarization states generated by the emission lens and only allow the first polarized light to enter the subsequent optical path.

9. The adaptive polarization state control system according to claim 8, characterized in that: The transmitting optical path also includes a reflector, and the transmitting and receiving shared module also includes a telescope and a polarization beam splitter. The reflector is used to reflect the first polarized light output by the polarization beam splitter prism to the polarization beam splitter, and the polarization beam splitter is used to reflect the first polarized light reflected by the reflector to the first polarization state control module. The telescope is used to receive the second polarized light generated by the first polarization state control module and transmit it.

10. The adaptive polarization state control system according to claim 1, characterized in that: The first polarization state control module includes one of an electro-optic modulator, a polarizer, and a liquid crystal polarization controller.

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