Optical power stabilizing system and method based on liquid crystal polarization grating

Abstract

The invention provides an optical power stabilization system and method based on a liquid crystal polarization grating, and belongs to the technical field of laser and quantum sensing measurement, and the system comprises a liquid crystal phase delayer, a linear polarizer, a quarter-wave plate, the liquid crystal polarization grating, a PD sensor, a drive control assembly, and an upper computer. The advantages of small size, high diffraction efficiency, stable performance and the like of the liquid crystal polarization grating are utilized, and a digital driving control assembly is combined, so that system errors caused by laser polarization axis fluctuation can be effectively reduced, and laser power can be regulated and stabilized; a three-dimensional structure of PBS is replaced by a small sheet structure of the liquid crystal polarization grating, the problem of optical path redundancy of a nuclear magnetic resonance gyroscope system is solved, the size is reduced, the integration level of the system is improved, the miniaturization development trend of the nuclear magnetic resonance gyroscope is facilitated, the deflection included angle between diffraction light of the system can be customized by changing the period of the liquid crystal polarization grating, and the stability of the system is improved. And the flexibility of the overall design of the system is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of lasers and quantum sensing and measurement, and in particular relates to an optical power stabilization system and method based on a liquid crystal polarization grating. Background Art

[0002] With the rapid development of precision measurement and micro-nano processing technologies, nuclear magnetic resonance gyroscopes based on quantum theory have made great progress; they sense external rotation through the spin characteristics of atomic nuclei and detect the precession frequency of atoms based on the magneto-optical rotation effect, with advantages such as high theoretical accuracy, strong anti-interference ability, and no gravity information coupling, showing great application potential and research value in fields such as inertial navigation and attitude control.

[0003] The pumping optical path is an important part of a nuclear magnetic resonance gyroscope; the pumping light polarizes alkali metal electrons in a polarization gas chamber, and at the same time, the electrons hyperpolarize noble gas nucleons to achieve the polarization of the atomic ensemble; existing systems generally use circularly polarized light as the pumping light source, and the stability of the pumping laser directly affects the effect and quality of atomic polarization. In order to achieve stable pumping of the atomic system, a laser power stabilization system is often used.

[0004] The existing power stabilization systems mainly include: a laser intracavity regulation system and an extracavity regulation system, where:

[0005] The intracavity regulation system stabilizes the power by directly changing parameters such as the internal current and temperature of the laser, but this scheme is prone to introducing laser frequency coupling errors and there are problems such as power fluctuations in the external optical path, making it difficult to ensure the stability of the optical power incident on the gas chamber.

[0006] The extracavity regulation system generally cascades a modulator (such as an electro-optic modulator EOM) and a polarization beam splitter (PBS) and uses them in combination with a fixed relative angle to control the power to reach the desired state to achieve the polarization of atoms. However, this scheme has problems such as low manual fixing accuracy, poor consistency, inconvenient adjustment, redundant components, and a large volume that is difficult to compress, and the vertical beam splitting characteristic of the polarization beam splitter limits the design freedom, bringing many inconveniences and obstacles to the miniaturization and integration of nuclear magnetic resonance gyroscopes. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides an optical power stabilization system and method based on a liquid crystal polarization grating, which utilizes the characteristics of small volume, stable performance, high diffraction efficiency, and easy integration of the liquid crystal polarization grating, combines with a digital drive control component to achieve optical power stabilization and regulation, can effectively reduce the noise influence introduced by laser power fluctuations and polarization axis fluctuations, make the optical path part more compact and easy to assemble, and at the same time improve the flexibility of system design.

[0008] An optical power stabilization system based on a liquid crystal polarization grating, comprising:

[0009] A liquid crystal phase retarder, a linear polarizer, a quarter-wave plate, a liquid crystal polarization grating, a PD sensor, a drive control component, and a host computer;

[0010] The liquid crystal phase retarder, the linear polarizer, the quarter-wave plate, and the liquid crystal polarization grating are cascaded to form an optical cascaded structure;

[0011] The liquid crystal phase retarder has an effective phase change range of 0-π at the incident laser wavelength. By utilizing the electro-optic birefringence characteristic of the liquid crystal and applying AC square wave voltages with different amplitudes greater than the threshold voltage to the indium tin oxide electrodes at both ends of the liquid crystal cell, different phase retardation amounts can be applied to the orthogonal polarization components of the incident laser, thereby changing the polarization state of the incident laser;

[0012] The linear polarizer and the quarter-wave plate are used to partially filter out optical noise, achieve power attenuation of the incident laser, and emit elliptical light in a specific polarization state, and the left-handed circular polarization component and the right-handed circular polarization component are relatively fixed; by adjusting the angle between the linear polarizer and the quarter-wave plate, the ellipticity of the emitted laser is changed, thereby changing the ratio of the left-handed circular polarization component to the right-handed circular polarization component;

[0013] The liquid crystal polarization grating: realizes the phase control of the incident laser through geometric phase;

[0014] The PD sensor: is used to detect the power fluctuation of the feedback light and output a current signal proportional to the laser power signal;

[0015] The drive control component: is used to collect the current signal, process to obtain a correction signal, and generate a drive signal to be applied to both ends of the indium tin oxide electrode of the liquid crystal phase retarder.

[0016] The host computer: communicates with the drive control component through the UART serial port, receives and decodes the power signal and the correction signal, and performs real-time dual-channel waveform display.

[0017] As an example, the PD sensor: realizes the output of the power signal of the feedback light through a photodiode.

[0018] As an example, the drive control component adopts: an architecture mode with a ZYNQ7020 main control chip as the core.

[0019] As an example, the drive signal is a square wave signal, specifically an AC square wave voltage signal.

[0020] An optical power stabilization method based on a liquid crystal polarization grating, including:

[0021] Step 1: After the incident laser passes through a liquid crystal phase retarder, a linear polarizer, and a quarter-wave plate in sequence, the output laser is shaped into elliptically polarized light;

[0022] Step 2: After the elliptically polarized light passes through a liquid crystal polarization grating, the output light is left-handed circularly polarized light and right-handed circularly polarized light, corresponding to the +1st order diffracted light and the -1st order diffracted light respectively. By controlling the ellipticity of the elliptically polarized light, the power ratio of the left-handed circularly polarized light to the right-handed circularly polarized light can be changed;

[0023] Step 3: For the deflection angle θ between the +1st order diffracted light and the -1st order diffracted light, the following equation is satisfied:

[0024]

[0025] where: λ is the wavelength of the incident laser, and ∧ is the period of the liquid crystal polarization grating;

[0026] The deflection angle θ can be adjusted by changing the period ∧ of the liquid crystal polarization grating;

[0027] Step 4: The -1st order diffracted light is used as the feedback light. The power fluctuation is detected by a PD sensor, and the output current signal is collected and processed by the drive control component to obtain a correction signal, and a drive signal is generated and applied to the indium tin oxide electrode of the liquid crystal phase retarder. By changing the laser phase retardation amount, the laser polarization state is controlled, thereby realizing the control of the laser power;

[0028] Step 5: At this time, the +1st order diffracted light is the output amount of the circularly polarized light with stable power.

[0029] As an example, for the liquid crystal polarization grating, the orientation of the liquid crystal molecules is relatively fixed. Within one liquid crystal polarization grating period ∧, the azimuth angle of the liquid crystal molecules changes continuously and linearly by 180°, which can generate the phase of an inclined, equal-phase surface modulation beam, thereby realizing the deflection of the incident beam.

[0030] Step 6: In order to better monitor the stable state of the optical power, the drive control component is connected by an upper computer electrical signal, and the power signal and the correction signal are monitored by real-time dual-channel waveform display.

[0031] As an example, the incident laser refers to: the laser emitted from the laser source, passing through the coupling optical fiber and entering the system optical path after preprocessing.

[0032] As an example, the correction signal is: an alternating square wave voltage signal.

[0033] Advantages of the present invention:

[0034] The present invention utilizes the advantages of a liquid crystal polarization grating, such as small size, high diffraction efficiency, and stable performance, and combines a digital drive control component to regulate and stabilize the optical power. Compared with the prior art, the advantages of the present invention are as follows:

[0035] ① The system directly emits circularly polarized light. By using the small sheet-like structure of the liquid crystal polarization grating to replace the three-dimensional structure of the PBS, the problem of redundant optical paths in the nuclear magnetic resonance gyroscope system can be reduced, the volume can be decreased, and the integration degree of the system can be improved, which is beneficial to the miniaturization development trend of the nuclear magnetic resonance gyroscope.

[0036] ② It can reduce the systematic error introduced by the fluctuation of the laser polarization axis and effectively regulate and stabilize the laser power.

[0037] ③ By changing the period of the liquid crystal polarization grating, the included angle of the laser emitted by the system can be customized, which improves the flexibility of the overall system design. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. is a schematic structural diagram of an optical power stabilization system based on a liquid crystal polarization grating according to the present invention.

[0039] Figure 2 FIG. is a diagram of the internal molecular structure of a liquid crystal polarization grating in an embodiment of an optical power stabilization system based on a liquid crystal polarization grating according to the present invention. (Liquid crystal polarization grating period ∧ = 9.12um)

[0040] Figure 3 FIG. is a schematic diagram of the diffraction and splitting of elliptically polarized light by a liquid crystal polarization grating in an embodiment of an optical power stabilization system based on a liquid crystal polarization grating according to the present invention. (θ = 10°) DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application. Refer to Figures 1 to 3 as shown:

[0042] An optical power stabilization system based on a liquid crystal polarization grating, referring to Figure 1 [[ID=3,5]]as shown, includes:

[0043] A liquid crystal phase retarder 1, a linear polarizer 2, a quarter-wave plate 3, a liquid crystal polarization grating 4, a PD sensor 7, a drive control component 8, and a host computer 10;

[0044] The cascaded structure of the liquid crystal phase retarder 1, the linear polarizer 2, the quarter-wave plate 3, and the liquid crystal polarization grating 4 constitutes an optical cascaded structure;

[0045] The liquid crystal phase retarder 1 has an effective phase change range of 0-π at the incident laser. Utilizing the electro-optic birefringence characteristic of the liquid crystal, by applying AC square wave voltages with different amplitudes greater than the threshold voltage to the indium tin oxide electrodes at both ends of the liquid crystal cell, different phase retardation amounts can be applied to the orthogonal polarization components of the incident laser, thereby changing the polarization state of the incident laser;

[0046] The linear polarizer 2 and the quarter-wave plate 3 are used to partially filter out optical noise, achieve power attenuation of the incident laser, and output elliptical light with a specific polarization state, and the left-handed circular polarization component and the right-handed circular polarization component thereof are relatively fixed; by adjusting the included angle between the linear polarizer 2 and the quarter-wave plate 3, the ellipticity of the output laser is changed, thereby changing the ratio of the left-handed circular polarization component to the right-handed circular polarization component;

[0047] The liquid crystal polarization grating 4: realizes the phase control of the incident laser through geometric phase;

[0048] The PD sensor 7: is used to detect the power fluctuation of the feedback light and output a current signal 11 proportional to the laser power;

[0049] The drive control component 8: is used to collect the current signal 11, process to obtain a correction signal, and generate a drive signal 9 to be applied to both ends of the indium tin oxide electrode of the liquid crystal phase retarder 1.

[0050] The host computer 10: communicates with the drive control component 8 through the UART serial port, receives and decodes the power signal and the correction signal, and performs real-time dual-channel waveform display.

[0051] As an example, the PD sensor 7: realizes the output of the power signal 11 of the feedback light through a photodiode.

[0052] As an example, the drive control component 8 adopts an architecture mode with a ZYNQ7020 main control chip as the core.

[0053] As an example, the drive signal 9 is a square wave signal, specifically an AC square wave voltage signal;

[0054] The advantage of using a square wave AC voltage is that it can avoid the polarization of liquid crystal molecules.

[0055] An optical power stabilization method based on a liquid crystal polarization grating includes:

[0056] Step 1: After the incident laser sequentially passes through the liquid crystal phase retarder 1, the linear polarizer 2, and the quarter-wave plate 3, the output laser is shaped into elliptical polarized light;

[0057] Step 2: After the elliptical polarized light passes through the liquid crystal polarization grating 4, the outgoing light is left-handed circularly polarized light 5 and right-handed circularly polarized light 6, corresponding to the +1st order diffracted light and the -1st order diffracted light respectively. By controlling the ellipticity of the elliptical polarized light, the power ratio between the left-handed circularly polarized light 5 and the right-handed circularly polarized light 6 can be changed;

[0058] Step 3: For the deflection angle θ between the +1st order diffracted light and the -1st order diffracted light, the following equation is satisfied:

[0059]

[0060] where: λ is the wavelength of the incident laser, and ∧ is the period of the liquid crystal polarization grating;

[0061] The deflection angle θ can be adjusted by changing the period ∧ of the liquid crystal polarization grating;

[0062] Step 4: The -1st order diffracted light 6 is used as the feedback light. The power fluctuation is detected by the PD sensor 7. The output current signal 11 is collected and processed by the drive control component 8 to obtain a correction signal, and then a drive signal 9 is generated and applied to the indium tin oxide electrode of the liquid crystal phase retarder 1. By changing the laser phase retardation amount, the laser polarization state is controlled, so as to realize the control of the laser power;

[0063] Step 5: At this time, the +1st order diffracted light 5 is the output amount of the circularly polarized light with stable power.

[0064] As an example, for the liquid crystal polarization grating 4, the orientation of the liquid crystal molecules is relatively fixed. Within one liquid crystal polarization grating period ∧, the azimuth angle of the liquid crystal molecules changes continuously and linearly by 180°, which can generate a phase modulation of the inclined and equal-phase surface modulated light beam, thereby realizing the deflection of the incident light beam.

[0065] Step 6: In order to better monitor the stable state of the optical power, the drive control component 8 is electrically connected to the host computer 10, and the power signal 11 and the correction signal are monitored by real-time dual-channel waveform display.

[0066] As an example, the incident laser refers to: the laser exits from the laser source, passes through the coupling optical fiber and enters the system optical path after preprocessing.

[0067] As an example, the correction signal is: an alternating square wave voltage signal.

[0068] Refer to Figure 2 As shown, it can be seen that the liquid crystal polarization grating realizes the laser phase regulation through the geometric phase. The orientation of the liquid crystal molecules is relatively fixed. Within one liquid crystal polarization grating period ∧, the azimuth angle of the liquid crystal molecules changes continuously and linearly by 180°, which can generate a phase modulation of the inclined equal-phase surface modulated light beam, thereby realizing the deflection of the incident light beam.

[0069] Referring to Figure 3 as shown, it can be seen that when elliptically polarized light is incident, the outgoing light is left-handed circularly polarized light 5 and right-handed circularly polarized light 6, corresponding to the +1st order diffracted light and the -1st order diffracted light respectively. By controlling the ellipticity of the elliptically polarized light, the intensity ratio of the outgoing left-handed and right-handed circularly polarized lights can be changed;

[0070] Example:

[0071] In this embodiment, the laser emits from the laser source, enters the system optical path after being preprocessed through the coupling optical fiber as the incident laser, and passes through the liquid crystal phase retarder 1. The LVE-ECB-5LC1 liquid crystal of Jingcui Optics Co., Ltd. (JCOPTIX) is selected, with an effective phase change range of 0-π at a laser wavelength of 795 nm, a response time of less than 10 ms, a threshold voltage of 1.1 V, a size of 12 mm×10 mm×2.2 mm, and a transmittance > 89%.

[0072] By applying square-wave AC voltages with different amplitudes in the range of 0-7 V to the indium tin oxide electrodes at both ends of the liquid crystal cell, different phase delays are applied to the orthogonal polarization components of the incident laser, thereby changing the laser polarization state. The square-wave frequency is 2 kHz to avoid the polarization of liquid crystal molecules.

[0073] The laser passes through the linear polarizer 2 and the quarter-wave plate 3. The linear polarizer 2 realizes the attenuation of the laser power. The fast axis of the quarter-wave plate 3 forms a fixed angle with the linear polarizer 2, making the outgoing light elliptically polarized light with an ellipticity of 22.5°. By rotating the quarter-wave plate 3, the laser ellipticity is changed to adjust the splitting ratio of the liquid crystal polarization grating 4.

[0074] The elliptically polarized light is split into the +1st order diffracted light 5 and the -1st order diffracted light 6 after passing through the liquid crystal polarization grating 4. The phase delay amount of the liquid crystal polarization grating 4 at a laser wavelength of 795 nm is 397.5 nm, and the diffraction efficiency is 98%. As Figure 2 and Figure 3 shown, when the liquid crystal polarization grating period ∧ = 9.12 um, the deflection angle θ between the +1 and -1 diffracted lights is 10°, and the deflection angle θ can be adjusted according to the change of the liquid crystal polarization grating period ∧.

[0075] The feedback light is detected by the PD sensor 7 to convert the power fluctuation into a current signal. The PD sensor 7 selects the S13957 chip. The drive control component 8 realizes sampling and control through the ZYNQ7020 main control chip. The sampling frequency is 100 Hz. The PID control algorithm is used to generate a correction signal. The square-wave voltage signal is generated by selecting the DAC8563 chip. By changing the laser phase delay amount, the laser polarization state is controlled, thereby realizing the control of the laser power.

[0076] The +1 order diffracted light 5 is the output of circularly polarized light after power stabilization. The host computer 10 communicates with the drive control component through the UART serial port, receives and decodes the power signal and the deviation correction signal, and performs real-time dual-channel waveform display.

[0077] It should be noted that for the method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all optional embodiments, and the actions involved are not necessarily essential to this application.

[0078] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Without further limitations, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0079] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method; based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to enable a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in various embodiments of this application.

[0080] The embodiments of this application have been described above in conjunction with the accompanying drawings. However, this application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of this application, those of ordinary skill in the art can also make many forms without departing from the purpose of this application and the scope protected by the claims, and all of them belong to the protection scope of this application.

[0081] Those of ordinary skill in the art will realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the embodiments of the present application can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0082] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0083] 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; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0084] In addition, the functional units in the various embodiments of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0085] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0086] The foregoing are only the preferred embodiments of the present invention. It should be understood that the description of the above embodiments is only used to help understand the method and its core idea of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An optical power stabilization system based on a liquid crystal polarization grating, characterized in that, Including: An optical cascaded structure, a PD sensor, a drive control component, and a host computer; A liquid crystal phase retarder, a linear polarizer, a quarter-wave plate, and a liquid crystal polarization grating are cascaded to form an optical cascaded structure; For the liquid crystal phase retarder, by utilizing the electro-optic birefringence characteristic of liquid crystal and applying AC square wave voltages with different amplitudes greater than the threshold voltage to the indium tin oxide electrodes at both ends of the liquid crystal cell, different phase retardation amounts can be applied to the orthogonal polarization components of the incident laser, thereby changing the polarization state of the incident laser; The linear polarizer and the quarter-wave plate are used to partially filter out optical noise, achieve power attenuation of the incident laser, and emit elliptical light with a specific polarization state. By adjusting the angle between the linear polarizer and the quarter-wave plate, the ellipticity of the emitted laser is changed, thereby changing the ratio of the left-handed circular polarization light component to the right-handed circular polarization light component; The liquid crystal polarization grating: realizes the phase control of the incident laser through geometric phase; The PD sensor: is used to detect the power fluctuation of the feedback light and output a current signal proportional to the laser power; The drive control component: is used to collect the power signal, process it to obtain a correction signal, and generate a drive signal to be applied across the indium tin oxide electrodes of the liquid crystal phase retarder; The host computer: communicates with the drive control component through the UART serial port, receives and decodes the power signal and the correction signal, and performs real-time dual-channel waveform display.

2. The optical power stabilization system based on a liquid crystal polarization grating according to claim 1, characterized in that The PD sensor realizes the output of the power signal of the feedback light through a photodiode.

3. The optical power stabilization system based on a liquid crystal polarization grating according to claim 1, characterized in that, The drive control component adopts an architecture mode with a ZYNQ7020 main control chip as the core.

4. A light power stabilization system based on a liquid crystal polarization grating according to claim 1, characterized in that, The drive signal is a square wave signal.

5. A method for stabilizing optical power based on a liquid crystal polarization grating, characterized in that, Including: Step 1: After the incident laser passes through the liquid crystal phase retarder, the linear polarizer, and the quarter-wave plate in sequence, the emitted laser is shaped into elliptically polarized light; Step 2: After the elliptically polarized light passes through the liquid crystal polarization grating, the emitted light is left-handed circular polarization light and right-handed circular polarization light, corresponding to the +1st order diffracted light and the -1st order diffracted light respectively. By controlling the ellipticity of the elliptically polarized light, the power ratio of the left-handed circular polarization light to the right-handed circular polarization light can be changed; Step 3. For the deflection angle θ between the +1st order diffracted light and the -1st order diffracted light, it satisfies the equation: Where: λ is the wavelength of the incident laser, and ∧ is the period of the liquid crystal polarization grating; The deflection angle θ can be adjusted by changing the period ∧ of the liquid crystal polarization grating; Step 4: The -1st order diffracted light is used as the feedback light. The power fluctuation is detected by the PD sensor, and the output power signal is collected and processed by the drive control component. After generating a correction signal, it is used as a drive signal to be applied to the indium tin oxide electrodes of the liquid crystal phase retarder. By changing the laser phase retardation amount, the laser polarization state is controlled, thereby realizing the control of the laser power; Step 5: At this time, the +1st order diffracted light is the output amount of the circularly polarized light with stable power; Step 6: In order to better monitor the stable state of the optical power, the drive control component is electrically connected to the host computer, and real-time dual-channel waveform display monitoring is performed on the power signal and the correction signal.

6. A method for stabilizing optical power based on a liquid crystal polarization grating according to claim 5, characterized in that For the liquid crystal polarization grating, the orientation of liquid crystal molecules is relatively fixed. Within one liquid crystal polarization grating period ∧, the azimuth angle of liquid crystal molecules changes continuously and linearly by 180°, which can generate the phase modulation of the inclined and equal phase plane of the light beam, thereby realizing the deflection of the incident light beam.

7. A method for stabilizing optical power based on a liquid crystal polarization grating according to claim 5, characterized in that The incident laser refers to the laser that exits from the laser source, passes through the coupling optical fiber and enters the system optical path after pretreatment.

8. A method for stabilizing optical power based on a liquid crystal polarization grating according to claim 5, characterized in that The correction signal is an alternating square wave voltage signal.

9. A method for stabilizing optical power based on a liquid crystal polarization grating according to claim 5, characterized in that, The PD sensor selects the S13957 chip.

10. A method for stabilizing optical power based on a liquid crystal polarization grating according to claim 5, characterized in that, For the liquid crystal phase retarder at a laser wavelength of 795 nm, its effective phase change range is 0-π, the response time is less than 10 ms, the threshold voltage is 1.1 V, the size is 12 mm × 10 mm × 2.2 mm, and the transmittance > 89%.

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