A control method of a frequency locking module and an adaptive frequency locking laser

Abstract

The application relates to the technical field of lasers, in particular to a frequency locking module control method and an adaptive frequency locking laser. The frequency locking module control method comprises the following steps: constructing an operation parameter data set of the frequency locking module; determining a hysteresis interval; acquiring a real-time working temperature of an optical F-P standard device; determining a current corresponding target temperature zone; determining a target laser source; calling an optimal working temperature of the frequency locking module in the target temperature zone, determining a temperature error and a temperature change rate; performing fuzzy inference and clear processing to determine a temperature correction amount; calling a fuzzy control weight coefficient of the target laser source in the target temperature zone, performing weighted processing on the temperature correction amount, superimposing the weighted correction amount to the optimal working temperature, and determining a temperature setting value; and driving the frequency locking module according to the temperature setting value. The frequency locking module control method greatly reduces the frequency drift amplitude, compresses the overall structure volume and hardware cost, is simple to operate, and is suitable for more application scenarios with requirements on volume and cost.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a control method for a frequency-locking module and an adaptive frequency-locking laser. Background Technology

[0002] Single-frequency narrow-linewidth lasers (SLLAs) offer excellent output power stability, low noise, and superior coherence, making them crucial and promising for applications in coherent detection, high-speed optical communication, distributed fiber optic sensing, and high-precision lidar. In specialized fields such as aerospace optical systems, high-precision meteorological detection, and ultra-fine laser processing, it is essential to actively lock the laser output frequency to an absolute frequency reference, i.e., laser frequency stabilization. Active frequency stabilization is a core prerequisite for suppressing frequency drift, establishing a stable frequency scale, and achieving high-precision observation and processing. The locking accuracy and long-term stability of the frequency locking module directly determine the performance of the laser's output frequency.

[0003] In existing laser frequency locking solutions, most do not have additional control mechanisms for the frequency locking module. The optical Fabry-Pérot etalon (FP) etalon is susceptible to environmental interference such as temperature and vibration, leading to frequency measurement deviations and fluctuations in the laser output frequency, resulting in unstable operation. Secondly, over a wide temperature range, the transmission peak position of the FP etalon shifts with temperature, causing frequency measurement drift and easily leading to laser loss of lock. Finally, most solutions require manual adjustment, using external equipment such as spectrum analyzers and wavelength meters to observe the frequency and manually lock it, which is a cumbersome process that requires a high level of operational experience. Summary of the Invention

[0004] This application provides a control method for a frequency-locking module and an adaptive frequency-locking laser, which significantly reduces the frequency drift amplitude, compresses the overall structural volume and hardware cost, is easy to operate, and is suitable for more application scenarios with requirements for size and cost.

[0005] The control method for a frequency-locking module provided in the first aspect of this application includes: constructing an operating parameter dataset for the frequency-locking module; wherein the operating parameter dataset includes weighting coefficients, which are calculated by the frequency-locking module based on different preset temperature zones; determining the hysteresis interval between two adjacent preset temperature zones; the hysteresis interval includes a forward entry threshold and a reverse exit threshold; obtaining the real-time operating temperature of the optical FP etalon in the frequency-locking module; determining the current target temperature zone based on the hysteresis interval of the real-time operating temperature; determining the target laser source to be frequency-locked; calling the optimal operating temperature of the optical FP etalon corresponding to the target laser source in the target temperature zone from the operating parameter dataset, and determining the temperature error and temperature change rate in combination with the real-time operating temperature of the optical FP etalon; performing fuzzy inference and declarative processing on both the temperature error and the temperature change rate to determine the temperature correction amount; calling the fuzzy control weighting coefficients corresponding to the frequency-locking module in the target temperature zone from the operating parameter dataset, weighting the temperature correction amount, and superimposing the weighted correction amount onto the optimal operating temperature to determine the temperature setpoint; and driving the frequency-locking module according to the temperature setpoint to adjust the real-time operating temperature of the optical FP etalon to the temperature setpoint.

[0006] In some feasible implementations, a dataset of operating parameters for the frequency locking module is constructed, including: the dataset comprising a first set of reference temperatures corresponding to the frequency locking module and the first laser source, a second set of reference temperatures corresponding to the frequency locking module and the second laser source, a first set of weighting coefficients corresponding to the first set of reference temperatures, and a second set of weighting coefficients corresponding to the second set of reference temperatures; wherein, the first set of reference temperatures includes the optimal operating temperatures of the frequency locking module corresponding to the first laser source in the low-temperature, medium-temperature, and high-temperature regions, respectively; the second set of reference temperatures includes the optimal operating temperatures of the frequency locking module corresponding to the second laser source in the low-temperature, medium-temperature, and high-temperature regions, respectively; the first set of weighting coefficients includes the first fuzzy control weighting coefficients corresponding to the low-temperature, medium-temperature, and high-temperature regions, and the second set of weighting coefficients includes the second fuzzy control weighting coefficients corresponding to the low-temperature, medium-temperature, and high-temperature regions.

[0007] In some feasible implementations, the hysteresis interval between two adjacent preset temperature zones is determined by: setting a positive entry threshold and a negative exit threshold; determining the low-to-medium hysteresis interval between the low-temperature zone and the medium-temperature zone by combining the boundary values ​​of the low-temperature zone and the medium-temperature zone, the positive entry threshold and the negative exit threshold; and determining the medium-to-high hysteresis interval between the medium-temperature zone and the high-temperature zone by combining the boundary values ​​of the medium-temperature zone and the high-temperature zone, the positive entry threshold and the negative exit threshold.

[0008] In some feasible implementations, the target temperature zone is determined based on the hysteresis interval of the real-time operating temperature. This includes switching the preset temperature zone in response to the relationship between the real-time operating temperature and the boundary value of the hysteresis interval corresponding to the preset temperature zone, so as to obtain the corresponding target temperature zone.

[0009] In some feasible implementations, both temperature error and temperature change rate are subjected to fuzzy inference and declarative processing to determine the temperature correction amount. This includes: mapping the temperature error to a first fuzzy language subset; mapping the temperature change rate to a second fuzzy language subset; establishing a fuzzy control model based on the first and second fuzzy language subsets; determining the fuzzy control amount based on the fuzzy control model; and performing weighted average declarative processing on the fuzzy control amount to obtain the temperature correction amount.

[0010] In some feasible implementations, the temperature correction amount is weighted and then superimposed on the optimal operating temperature to determine the temperature setpoint. This includes: determining the target fuzzy control weight coefficient corresponding to the target temperature zone; the target fuzzy control weight coefficient being either the first fuzzy control weight coefficient or the second fuzzy control weight coefficient; multiplying the temperature correction amount by the target fuzzy control weight coefficient to obtain the weighted correction amount, and then superimposing the weighted correction amount on the optimal operating temperature to determine the temperature setpoint.

[0011] In some feasible implementations, the frequency locking module is driven according to the temperature setpoint to adjust the real-time operating temperature of the optical FP etalon to the temperature setpoint, including: converting the temperature setpoint into a corresponding analog voltage; and driving the frequency locking temperature control circuit and Peltier cooling element of the frequency locking module based on the analog voltage to adjust the real-time operating temperature of the optical FP etalon to the temperature setpoint.

[0012] In some feasible implementations, the control method of the frequency locking module also includes: in response to the target laser source being switched, repeatedly executing the step of determining the target laser source to be frequency locked.

[0013] The control method for the frequency locking module provided in the first aspect of this application dynamically tunes the temperature setpoint of the temperature control system through a software algorithm running on the processing unit. Without changing the inherent parameter configuration of the hardware PI controller, it effectively achieves the effect of dynamically adjusting the parameters of the hardware PI controller according to the operating conditions, ultimately realizing wide-temperature adaptive control across the entire performance operating range. This application introduces a simplified, lightweight fuzzy intelligent control algorithm. It uses fuzzy control logic to adaptively match the control characteristics of different operating temperature zones, superimposing pre-stored weight coefficients for each preset temperature zone. Different temperature zones have different fuzzy control output weight coefficients. The algorithm compensates and tunes the initial reference setpoint temperature using the weight coefficients matched to the current temperature zone, ultimately generating a dynamically corrected temperature setpoint. This corrected temperature setpoint is then sent to a fixed-parameter hardware PI control loop for closed-loop regulation. When changes in ambient temperature or the need for the laser to switch output frequencies causing a shift in the operating temperature range, the fuzzy intelligent control algorithm automatically switches the weighting coefficients for the corresponding temperature range and readjusts the temperature setpoint. Throughout the entire control process, the parameters of the hardware PI loop remain constant, automatically adapting to the operating characteristics of different wide temperature ranges. In this entire control process, the hardware is responsible for performing high-precision temperature stabilization control, while the software is responsible for intelligently matching control parameters under different operating conditions. The entire solution requires no modifications to the original hardware circuit structure and exhibits strong compatibility and portability across different hardware platforms.

[0014] The adaptive frequency-locked laser provided in the second aspect of this application includes: a first laser source configured to output a first laser; a second laser source configured to output a second laser; the first laser and the second laser have different frequencies; a dual-frequency laser switching unit, one end of which is connected to the first laser source and the second laser source respectively, configured to switch between the first laser and the second laser to output a target laser; a frequency-locking module connected to the other end of the dual-frequency laser switching unit, configured to lock the frequency of the target laser; a laser frequency detection circuit connected to the frequency-locking module, configured to acquire the optical signal of the target laser after passing through the frequency-locking module and convert it into an electrical signal for output; a laser frequency control module connected to the first laser source and the second laser source respectively, configured to adjust the output frequency of the laser from the target laser source; and a controller connected to the frequency-locking module, the laser frequency detection circuit, and the laser frequency control module respectively.

[0015] In some feasible implementations, the adaptive frequency-locked laser also includes an isolation coupler and an amplification stage; the frequency-locking module includes an optical FP etalon, a first photodetector, a second photodetector, a first temperature sensor, a second temperature sensor, a frequency-locking temperature control circuit, and a Peltier cooling element; wherein, the first port of the isolation coupler is connected to the dual-frequency laser switching unit, the second port of the isolation coupler is connected to the optical FP etalon, the first photodetector is connected to the laser frequency detection circuit; the other end of the optical FP etalon is connected to the second photodetector, and the end of the second photodetector facing away from the optical FP etalon is connected to the laser frequency detection circuit; the first temperature sensor is connected to the controller, and the second temperature sensor is connected to both the Peltier cooling element and the frequency-locking temperature control circuit; the frequency-locking temperature control circuit is also connected to both the controller and the Peltier cooling element; the third port of the isolation coupler is connected to the amplification stage.

[0016] The adaptive frequency-locked laser provided in the second aspect of this application integrates a shared FP etalon frequency-locking module designed for dual-frequency lasers, along with a graded temperature acquisition and closed-loop temperature control circuit. This enables shared frequency-locking control of two different frequency lasers without requiring a separate frequency-locking structure for each laser source. It also effectively counteracts the effects of ambient temperature fluctuations and laser heating on the resonant characteristics of the optical FP etalon, keeping the output frequency of different lasers consistently and stably locked at a preset operating point. This significantly reduces the frequency drift of the laser output, while also compressing the overall structural size and hardware cost of the laser. It is easy to operate and adaptable to more application scenarios with requirements for size and cost. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an adaptive frequency-locked laser provided in an embodiment of this application; Figure 2 This is a schematic diagram of another adaptive frequency-locked laser provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a frequency locking module provided in an embodiment of this application; Figure 3 (a) is the front view of the frequency locking module; Figure 3 (b) is a side view of the frequency locking module; Figure 4 This is a flowchart illustrating a control method for a frequency locking module provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a frequency locking module temperature control circuit provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a frequency locking module temperature drive circuit provided in an embodiment of this application; Figure 7 This is a block diagram of a frequency locking module control algorithm provided in an embodiment of this application; Figure 8 This is a flowchart illustrating the control method of the frequency locking module in a specific implementation provided in this application embodiment.

[0019] Illustration markings: 10. First laser source; 20. Second laser source; 30. Dual-frequency laser switching unit; 40. Frequency locking module; 401. Optical FP etalon; 402. Rectangular mounting bracket; 403. Beam splitter; 404. Peltier cooling element; 405. First photodetector; 406. First temperature sensor; 407. Second temperature sensor; 408. Second photodetector; 409. Frequency locking temperature control circuit; 410. Mounting module; 411. Frequency locking module housing; 412. Beam splitter mounting bracket; 50. Laser frequency detection circuit; 60. Laser frequency control module; 70. Controller; 80. Isolation coupler; 90. Amplification stage. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0021] In the following description, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0022] Furthermore, in this application, directional terms such as "upper," "lower," "inner," and "outer" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0023] Single-frequency, narrow-linewidth external-cavity semiconductor lasers are indispensable core light sources in many cutting-edge scientific research and engineering fields, such as quantum optics research and high-precision measurement, playing a decisive supporting role in the final performance of experiments and applications across the entire field. However, the actual output laser frequency is not absolutely stable and is easily affected by various factors such as internal temperature fluctuations, mechanical stress deformation, material aging, and external environmental vibrations, temperature and humidity changes, and airflow disturbances, resulting in unavoidable frequency drift. When the laser output frequency drifts beyond the allowable range of application specifications, an absolute reference fundamental frequency with high precision and the ability to maintain stable performance over a long period is needed to lock and calibrate the laser output frequency, ensuring that the laser output performance meets application requirements.

[0024] Single-frequency narrow-linewidth lasers, with their outstanding advantages such as good output power stability, low intensity and phase noise, and excellent temporal and spatial coherence, are in critical demand in many cutting-edge technology and engineering fields, including coherent detection, high-speed optical communication, distributed fiber optic sensing, and high-precision lidar, and possess extremely broad and far-reaching prospects for industrial application. Especially in special application fields such as aerospace payload optical systems, high-precision atmospheric and meteorological detection, and ultra-fine laser precision machining, where the stability of the light source is extremely critical, it is essential to actively lock the laser's output frequency to a predetermined absolute frequency reference to ensure long-term stable output that meets performance requirements. This locking process is known as laser frequency stabilization. Active frequency stabilization is a core prerequisite for suppressing laser output frequency drift caused by environmental interference, establishing a stable and reliable laser frequency scale, and ultimately achieving high-resolution observation and detection, high-precision parameter measurement, and high-precision laser processing. It is also an indispensable condition for ensuring the smooth operation of related applications. Therefore, the frequency locking accuracy and long-term operational stability of the laser frequency locking module used to lock the absolute frequency reference directly determine the final output frequency performance of the entire laser system.

[0025] The existing laser frequency locking solutions have several main problems: First, most existing solutions lack additional control mechanisms for the frequency locking module. The optical FP etalon inside the module is easily affected by environmental factors such as temperature changes and mechanical vibrations, leading to frequency measurement disturbances and ultimately causing fluctuations in the output frequency during the overall laser frequency stabilization process, resulting in unstable laser operation. Second, within a wide operating temperature range, the transmission peak position of the optical FP etalon shifts with temperature, causing significant drift in the overall frequency measurement. This can easily lead to laser loss of lock and inability to maintain a stable output frequency. Finally, most existing solutions require manual adjustment by the user and necessitate the use of external auxiliary equipment such as spectrum analyzers and wavelength meters for frequency observation before manually completing the frequency locking operation. The entire process is cumbersome and requires a high level of user experience.

[0026] To address the shortcomings of existing technologies, the frequency-locking module control method proposed in this application can automatically adjust the optimal operating temperature output value based on a fuzzy intelligent control algorithm within a wide operating temperature range to meet the current operating conditions. This is combined with a hardware-level fixed proportional-integral (PI) dual-closed-loop control architecture for regulation. The overall solution inherently possesses strong adaptive adjustment capabilities, fast regulation response speed, and high frequency-locking accuracy. Furthermore, this solution uses only a single shared standard frequency-locking module to achieve frequency stabilization control of dual-frequency lasers with switchable operating modes according to different ambient temperatures, eliminating the need for separate frequency-locking modules for each laser and ensuring long-term high stability of the laser output frequency. This frequency-locking module can adaptively adjust the operating state of two different frequency lasers within a wide temperature range, maintaining the accuracy and stability of the optical FP etalon. Therefore, this frequency-locking module control method has significant advantages such as high adjustment accuracy, high application versatility, and low overall cost.

[0027] Figure 1 This is a schematic diagram of an adaptive frequency-locked laser provided in an embodiment of this application.

[0028] See Figure 1 As shown, the adaptive frequency-locked laser includes: a first laser source, a second laser source, a dual-frequency laser switching unit, a frequency-locking module, a laser frequency detection circuit, a laser frequency control module, and a controller.

[0029] The first laser source 10 is configured to output the first laser.

[0030] The second laser source 20 is configured to output a second laser; the first laser and the second laser have different frequencies. The first laser source 10 and the second laser source 20 can be semiconductor lasers with different wavelengths.

[0031] In one example, the first laser source 10 and the second laser source 20 can be two single-frequency narrow-linewidth external cavity semiconductor lasers with different frequencies.

[0032] The dual-frequency laser switching unit 30 is connected at one end to the first laser source 10 and the second laser source 20 respectively, and is configured to switch between the first laser and the second laser to output the target laser.

[0033] The target laser is one of the first laser and the second laser. When the dual-frequency laser switching unit 30 is switched to connect with the first laser source 10, the target laser is the first laser. When the dual-frequency laser switching unit 30 is switched to connect with the second laser source 20, the target laser is the second laser.

[0034] In one specific implementation, the dual-frequency laser switching unit 30 can be a magneto-optical switch. Magneto-optical switches are characterized by fast switching speed and high isolation, enabling them to quickly respond to channel switching commands from the controller 70 and complete the output switching between the first and second lasers in a short time. Simultaneously, they can effectively block reflected light from the back-end optical path from returning to the light source, preventing reflected light from interfering with the stability of the light source output and ensuring the reliability of the frequency switching process.

[0035] The frequency locking module 40, connected to the other end of the dual-frequency laser switching unit 30, is configured to lock the frequency of the target laser.

[0036] Specifically, the frequency locking module 40 is connected between the dual-frequency laser switching unit 30 and the laser frequency detection circuit 50. It receives the target laser after switching and locks the frequency of the target laser at the reference frequency point of the etalon based on the transmission characteristics of the optical FP etalon 401. The laser frequency detection circuit 50 is configured to acquire the optical signal of the target laser after passing through the frequency locking module 40 and convert it into an electrical signal output.

[0037] The laser frequency control module 60 is connected to the first laser source 10 and the second laser source 20 respectively, and is configured to adjust the output frequency of the laser from the target laser source.

[0038] Specifically, the laser frequency control module 60 is used to control the frequency of the laser. When the first laser is the target laser, the laser frequency control module 60 is used to control the frequency of the first laser. When the second laser is the target laser, the laser frequency control module 60 is used to control the frequency of the second laser.

[0039] The controller 70 is connected to the frequency locking module 40, the laser frequency detection circuit 50 and the laser frequency control module 60 respectively, and is used to receive the detection signals fed back by each functional device and send control commands to each functional device.

[0040] In laser applications, narrow-linewidth semiconductor lasers are core laser devices, and the stability of their output laser frequency directly determines their application performance. However, in practical applications, fluctuations in the external ambient temperature can change the optical length of the laser resonator, and long-term stability deviations in various optical components can also interfere with the output characteristics of the resonator. These interference factors, which cannot be completely eliminated, will ultimately cause undesirable drift in the laser output frequency, affecting the normal operation of the laser system.

[0041] To address this issue, this application embodiment employs a frequency-locking module 40 that integrates a shared optical FP etalon 401 designed for dual-frequency lasers. The frequency-locking module 40 with the optical FP etalon 401 can simultaneously perform stable frequency-locking control for two lasers with different frequencies within the same operating band, effectively suppressing frequency drift.

[0042] Two narrow-linewidth semiconductor laser sources, 10 and 20, with different wavelengths, serve as dual-frequency seed sources. Their output light enters the two input terminals of the dual-frequency laser switching unit 30, respectively. The dual-frequency laser switching unit 30 selects the conduction channel according to the instructions of the controller 70 and outputs either the first laser or the second laser from the output terminal, thereby realizing the switching function of dual-frequency laser.

[0043] Figure 2 This is a schematic diagram of another adaptive frequency-locked laser provided in an embodiment of this application; Figure 3 This is a schematic diagram of a frequency locking module provided in an embodiment of this application. Figure 3 (a) is the front view of the frequency locking module. Figure 3 (b) is a side view of the frequency locking module.

[0044] Combination Figure 2 and Figure 3 As shown, in some feasible implementations, the adaptive frequency-locked laser also includes an isolation coupler 80 and an amplification stage 90.

[0045] The frequency locking module 40 is encapsulated within a dedicated housing. Its internal components include an optical FP etalon 401, a back-shaped mounting bracket 402, a beam splitter 403, a Peltier cooling element 404, a first photodetector 405, a first temperature sensor 406, a second temperature sensor 407, a second photodetector 408, a frequency locking temperature control circuit 409, a fixing mounting module 410, the housing of the frequency locking module 40, and a mounting bracket for the beam splitter 403. Each component is fixedly mounted on the corresponding fixing mounting module 410 according to a preset positional relationship.

[0046] Specifically, the first port of the isolation coupler 80 is connected to the dual-frequency laser switching unit 30 to receive the target laser signal output by the dual-frequency laser switching unit 30; the second port of the isolation coupler 80 is connected to the optical FP standard 401 in the form of spatial light to realize the split output of the target laser. One of the split lasers is sent to the first photodetector 405 for signal conversion through the beam splitter 403. The end of the first photodetector 405 away from the isolation coupler 80 is connected to the laser frequency detection circuit 50 to transmit the converted electrical signal to the laser frequency detection circuit 50 for subsequent processing.

[0047] The optical FP etalon 401, as the core optical element for frequency selection in the frequency locking module 40, has its other end, which outputs the transmitted laser signal, connected to the second photodetector 408 in spatial light form. This converts the transmitted light signal into an electrical signal that can be recognized by the circuit. The other end of the second photodetector 408, away from the output of the optical FP etalon 401, is connected to the laser frequency detection circuit 50, which stably transmits the converted electrical signal to the frequency detection module for subsequent analysis and processing. The first temperature sensor 406, used to collect the ambient temperature around the first photodetector 405, is connected to the controller 70, and transmits the collected ambient temperature data to the controller 70 for storage and calculation in real time. The second temperature sensor 407, used to collect the operating temperature of the optical FP etalon 401, is connected to the Peltier cooling element 404 for performing temperature adjustment and the frequency-locked temperature control circuit 409 for controlling the temperature adjustment process, and synchronously transmits the collected temperature signal to the back-end control unit. The frequency-locked temperature control circuit 409, which is responsible for controlling the temperature of the frequency-locked module 40, is also connected to the controller 70 and the Peltier cooling element 404 for generating temperature regulation, receiving the temperature regulation command issued by the controller 70 and outputting the corresponding drive control signal to the Peltier cooling element 404. After the target laser is split into multiple inputs, the third port of the isolation coupler 80, which is used to output the remaining unsplittered laser, is connected to the amplification stage 90 for amplifying laser power, and sends the target laser to the subsequent power amplification stage.

[0048] It should be emphasized that the connection mentioned in the embodiments of this application can be a physical connection, such as an electrical connection or an optical fiber connection. Of course, it can also refer to a connection in the form of spatial light, such as a connection between two components without a physical connection, but a connection between them for transmitting and receiving signals in the form of spatial light.

[0049] In some feasible implementations, after the laser signal output from the coupler enters the frequency-locking module 40, the entire optical signal transmission proceeds step by step according to the preset optical path. The incident light is incident horizontally and passes directly through the pre-fixed beam splitter 403. The beam splitter 403 is installed at a 45° angle according to the design requirements, forming a 45° angle with the propagation direction of the incident light. According to the principle of optical beam splitting, the beam splitter 403 will split the original incident laser into two beams with different energy ratios, namely reflected light and transmitted light. One path of reflected light, deflected by 90° after refraction, enters the first photodetector 405 perpendicularly. This signal serves as the reference light in the optical path. The first photodetector 405, according to its structural design, is fixedly mounted on the side of the frequency-locking module 40 housing to maintain the stability of the optical path position. The other path of transmitted light, unreflected, passes through the optical FP etalon 401 along its original horizontal direction and directly enters the second photodetector 408 located directly behind the optical FP etalon 401. This signal, carrying interference information from the optical FP etalon 401, is the interference light. The two photodetectors are connected to an external laser frequency detection circuit 50 via corresponding signal pins to convert the optical signal into an analyzable electrical signal. In the entire optical path layout, the beam splitter 403, the optical FP etalon 401, and the centers of the two photodetectors are all on the same horizontal plane, ensuring the coaxiality of the optical path transmission and preventing light deflection loss and positional deviation.

[0050] The rectangular mounting bracket 402 is integrally machined from a high thermal conductivity metal with high thermal conductivity and low thermal deformation. This one-piece machining process eliminates seams, resulting in greater structural stability and avoiding positional deviations caused by assembling multiple components. The optical FP datum 401 is installed in the hollow cavity in the center of the rectangular mounting bracket 402 using a non-hard contact, non-compression prestressing installation method. This design prevents irreversible deformation of the optical structure of the FP datum 401 caused by compressive stress during assembly, preserving the original optical accuracy of the FP datum 401 to the greatest extent possible.

[0051] The gap between the outer periphery of the optical FP etalon 401 and the inner wall of the frame is filled with a highly thermally conductive flexible thermal pad or a thermally conductive silicone gasket. The flexible filling achieves uniform heat conduction in the circumferential direction of the optical FP etalon 401, which avoids the compressive stress caused by rigid contact and ensures that heat can be smoothly discharged in the circumferential direction.

[0052] The bottom surface of the U-shaped mounting bracket is evenly coated with thermally conductive silicone grease, achieving large-area contact with the cold surface of the Peltier cooling element 404. This maximizes the thermal contact area, reduces contact thermal resistance, and ensures efficient heat transfer. A countersunk hole is provided at a predetermined position on the side of the U-shaped bracket. The second temperature sensor 407 is placed inside this countersunk hole and sealed with adhesive. This countersunk hole is located close to the center of the outer wall of the U-shaped bracket, enabling precise acquisition of the actual operating temperature of the optical FP etalon 401 and ensuring accurate temperature detection. This U-shaped mounting bracket combines multiple functions, including centered positioning, stress-free fixing, circumferential heat distribution, and thermal conduction. Its compact structure and easy assembly effectively reduce the adverse effects of ambient temperature fluctuations on the optical characteristics and frequency locking accuracy of the optical FP etalon 401.

[0053] The first temperature sensor 406 monitors the ambient temperature of the frequency-locking module 40 in real time and transmits the collected real-time operating temperature signal stably to the matching controller 70. The second temperature sensor 407 monitors the actual operating temperature of the optical FP etalon 401 in real time and transmits the collected temperature signal to the corresponding frequency-locking temperature control circuit 409. After receiving the temperature control command sent by the controller 70 according to the preset control logic, the frequency-locking temperature control circuit 409 drives the Peltier cooling element 404 installed below the optical FP etalon 401 to perform temperature regulation operation according to the command requirements. It stably ensures that the FP cavity length of the optical FP etalon 401 remains constant in a wide temperature range throughout the entire operating range, thereby providing a long-term reliable and temperature-drift-free stable frequency reference point for the entire laser system.

[0054] When the temperature of the frequency-locking module 40 changes within different ambient temperature ranges, it directly alters the cavity operating parameters of the optical FP etalon 401, leading to a shift or irregular fluctuation in the frequency of the interference light passing through the optical FP etalon 401. Furthermore, when the laser needs to switch between different laser source frequencies, the operating temperature required for the frequency-locking module 40 to maintain its optimal operating state also changes, and it does not remain at a uniform constant value. To eliminate various temperature-related error sources during frequency locking and stabilization at their root, and to ensure the long-term stability of the optical FP etalon 401 output detection frequency reference, this application proposes a dedicated adaptive control method and corresponding device for the frequency-locking module 40. This solution constructs a dual-closed-loop adaptive temperature control system, combining a dynamic parameter adjustment mechanism with a dual-frequency operating temperature matching strategy, to accurately solve the temperature drift problem of the optical FP etalon 401 within the full-performance, wide-temperature-range operating range of the frequency-locking module 40, effectively improving the long-term stability and overall operational reliability of the dual-frequency laser's frequency locking and stabilization operation.

[0055] Thus, the adaptive frequency-locking laser provided in this application, by integrating a frequency-locking module 40 with a shared optical FP etalon 401 designed for dual-frequency lasers, and in conjunction with a graded temperature acquisition and closed-loop temperature control circuit, can achieve shared frequency-locking control for two different frequency lasers without requiring a separate frequency-locking structure for each laser source. It also effectively counteracts the effects of ambient temperature fluctuations and laser heating on the resonant characteristics of the optical FP etalon 401, keeping the output frequencies of different lasers consistently and stably locked at a preset operating point. This significantly reduces the frequency drift of the laser output, while also compressing the overall structural volume and hardware cost of the laser. It is simple to operate and adaptable to more application scenarios with requirements for size and cost. Corresponding to the aforementioned adaptive frequency-locking laser device embodiment, this application also provides an embodiment of an adaptive frequency-locking laser control method. This adaptive frequency-locking laser control method dynamically tunes the temperature setpoint of the temperature control system through a software algorithm running on the processing unit. Without changing the inherent parameter configuration of the hardware PI controller, it effectively achieves the effect of dynamically adjusting the parameters of the hardware PI controller according to the operating conditions, ultimately realizing wide-temperature adaptive control across the entire performance operating range. This application introduces a simplified, lightweight fuzzy intelligent control algorithm. It utilizes fuzzy control logic to adaptively match the control characteristics of different operating temperature zones, superimposing pre-stored weight coefficients for each preset temperature zone. Different temperature zones have distinct fuzzy control output weight coefficients. The algorithm compensates and tunes the initial reference setpoint temperature using the weight coefficient matched to the current temperature zone, ultimately generating a dynamically corrected temperature setpoint. This corrected setpoint is then fed into a fixed-parameter hardware PI control loop for closed-loop regulation. When the external ambient temperature changes or the laser needs to switch to different output frequencies, causing a shift in the operating temperature zone, the fuzzy intelligent control algorithm automatically switches the corresponding temperature zone's weight coefficients and readjusts the temperature setpoint. Throughout the control process, the parameters of the hardware PI loop remain constant, automatically adapting to the operating characteristics of different wide temperature zones. In the entire control process, the hardware is responsible for high-precision temperature stabilization control, while the software is responsible for intelligent matching of control parameters under different operating conditions. The entire solution requires no changes to the original hardware circuit structure and exhibits strong compatibility and portability across different hardware platforms.

[0056] Figure 4 This is a flowchart illustrating a control method for a frequency locking module provided in an embodiment of this application.

[0057] See Figure 4 As shown, the control method for the frequency locking module provided in this application embodiment may include the following steps S1 to S9.

[0058] Step S1: Construct the operating parameter dataset for the frequency locking module The system consists of two laser sources with different output frequencies. The operating parameter dataset includes weighting coefficients, which are calculated by the frequency locking module based on different preset temperature zones.

[0059] In this step, the temperature zone is preset. There are also multiple preset temperature zones, which are divided according to the specific range of ambient temperature that the frequency-locking module needs to adapt to during actual operation. The division process comprehensively considers various application scenarios of the adaptive frequency-locking laser, taking into account the common ambient temperature fluctuation characteristics of different scenarios. The complete temperature range that the adaptive frequency-locking laser may cover is divided into multiple continuous, clearly defined segmented intervals to cover various ambient temperature conditions that the laser may encounter during operation, ensuring that every possible ambient temperature falls within the corresponding preset temperature zone.

[0060] In a specific implementation, the operating temperature can be divided into three zones, namely the low temperature zone... Medium temperature zone and high temperature zone .

[0061] ; in, This is the minimum temperature. The temperature is low. This is a high temperature value. This represents the maximum temperature.

[0062] The operating parameter dataset includes a first reference temperature set corresponding to the frequency locking module and the first laser source, a second reference temperature set corresponding to the frequency locking module and the second laser source, a first weighting coefficient set corresponding to the first reference temperature set, and a second weighting coefficient set corresponding to the second reference temperature set. The first reference temperature set includes the operating temperatures of the frequency locking module corresponding to the first laser source in the low-temperature, medium-temperature, and high-temperature regions, respectively. The second reference temperature set includes the operating temperatures of the frequency locking module corresponding to the second laser source in the low-temperature, medium-temperature, and high-temperature regions, respectively. The first weighting coefficient set includes the first fuzzy control weighting coefficients corresponding to the low-temperature, medium-temperature, and high-temperature regions, and the second weighting coefficient set includes the second fuzzy control weighting coefficients corresponding to the low-temperature, medium-temperature, and high-temperature regions, respectively.

[0063] Based on the optical transmission characteristics of the optical FP etalon in the frequency locking module, and combined with the actual results obtained from repeated tests conducted in a laboratory environment, we selected the temperature point with the optimal transmission peak stability, minimum laser wavelength drift, and lowest internal optical stress within the corresponding temperature range from multiple selectable temperature points. This temperature point was then determined as the optimal operating temperature of the laser source within the corresponding temperature range. When the frequency locking module is responsible for detecting the output laser frequency of the first laser source, the optimal operating temperature of the frequency locking module in the pre-defined low-temperature zone is... The optimal operating temperature corresponding to the medium temperature range is: The optimal operating temperature corresponding to the high-temperature zone is When the frequency locking module is responsible for detecting the output laser frequency of the second laser source, the optimal operating temperature corresponding to the same low-temperature zone is: The optimal operating temperature corresponding to the medium temperature range is: The optimal operating temperature corresponding to the high-temperature zone is Through preliminary offline calibration testing and controller parameter engineering tuning, the fuzzy control output weighting coefficients of the frequency locking module were ultimately determined to be the first fuzzy control weighting coefficients corresponding to the low-temperature region when the first laser source operates in three different temperature zones. The first fuzzy control weight coefficient corresponding to the medium temperature zone The first fuzzy control weight coefficient corresponding to the high temperature zone When the second laser source operates in three different temperature zones, the fuzzy control output weighting coefficients corresponding to the frequency locking module are respectively the second fuzzy control weighting coefficients corresponding to the low-temperature zone. The second fuzzy control weight coefficient corresponding to the medium temperature zone The second fuzzy control weight coefficient corresponding to the high temperature zone .

[0064] A dataset of system operating parameters composed of different operating temperatures. And save it to the controller's storage area.

[0065] .

[0066] The controller integrated into the adaptive frequency-locked laser uses a first temperature sensor pre-integrated within the adaptive frequency-locked laser system to collect the ambient temperature in real time, according to a preset sampling frequency, to monitor the laser's current operating state. The collected real-time operating temperature data is then standardized and used as the core basis for subsequent matching of the adaptive frequency-locked laser's operating parameters, providing an accurate and reliable temperature judgment foundation for the entire adaptive parameter matching process. After obtaining the accurate current ambient temperature value, the controller compares the current temperature value with the range of each pre-defined and stored temperature zone to determine the target temperature zone to which the adaptive laser should currently operate. Then, it accurately searches for and automatically imports the necessary operating parameters for the current temperature zone, ensuring the stable and reliable operation of the adaptive frequency-locked laser, from the complete operating parameter dataset pre-stored in the system storage unit. The entire search and import process is completely automated by the control system, requiring no manual intervention to adjust the parameters. For example, within the pre-defined low-temperature zone, the current operating parameters of the frequency-locking module are... The target temperature zone is one of the preset temperature zones.

[0067] Step S2: Determine the hysteresis interval between two adjacent preset temperature zones; the hysteresis interval includes the positive entry threshold. and reverse exit threshold .

[0068] In the step of determining the hysteresis interval of adjacent preset temperature zones, the conventional approach of setting a single temperature switching boundary point for each adjacent temperature zone, as in traditional temperature zoning control schemes, is no longer adopted. Instead, for each pair of adjacent temperature zones, instead of using a uniform switching rule, dedicated temperature switching parameters are configured independently. For each pair of adjacent temperature zones for which the hysteresis interval needs to be determined, the forward entry threshold and the corresponding reverse exit threshold of the current temperature zone for the adjacent temperature zone are clearly set. This forms a dedicated hysteresis buffer zone with a stabilizing effect at the original single temperature boundary position between the two adjacent temperature zones. When the ambient temperature of the adaptive frequency-locked laser fluctuates due to changes in external conditions, and the final temperature falls within the specially set hysteresis buffer range, the entire control system will maintain the previously determined temperature zone of the laser and will not perform any temperature zone switching operation in response to the temperature fluctuation. Only when the continuous change in ambient temperature is large enough to completely cross the pre-set entry or exit threshold of the corresponding temperature zone and meet the preset temperature zone switching trigger conditions will the system officially perform the temperature zone switching operation, update the determination result of the current temperature zone of the adaptive frequency-locked laser, and re-call the complete set of pre-matched operating parameters for the corresponding temperature zone.

[0069] Under this optimized design logic, the state machine used to determine the current operating temperature range of the adaptive frequency-locked laser inherently possesses a stable memory retention characteristic: the state machine always retains the previously completed and effective temperature range assignment results, and will not arbitrarily overturn the original conclusion or update the temperature range determination result due to the detection of minor temperature changes. This memory retention characteristic optimizes the stability of temperature range determination from the underlying logic. When the ambient temperature fluctuates slightly near the critical boundary between two adjacent temperature ranges, these changes will not alter the actual operating environment conditions of the adaptive frequency-locked laser; they will only cause meaningless fluctuations in stable operation. These fluctuations will be completely filtered out by the hysteresis interval specifically designed for this scenario, and will not affect the already confirmed and effective temperature range determination results, nor trigger any unnecessary temperature range determination update operations. This avoids the problem of repeated jumps in the temperature zone determination result of the adaptive frequency-locking laser and frequent meaningless jitters in the setting value of the operating parameter corresponding to the temperature zone when the ambient temperature fluctuates slightly near the critical temperature point. It effectively solves the problem of frequent parameter switching caused by such small fluctuations, and also avoids the additional interference to the stable operation of the adaptive frequency-locking laser caused by repeated temperature zone switching and parameter update operations. It can effectively ensure the stability of the temperature control process of the frequency-locking module and the long-term stability of the overall laser frequency-locking process.

[0070] In a specific instance, step S2 may include steps S21 to S23 as follows.

[0071] Step S21: Set the positive entry threshold and reverse exit threshold .

[0072] In this step, for the three different laser operating temperature zones we have pre-defined—low temperature zone, medium temperature zone, and high temperature zone—a positive entry threshold needs to be set between each pair of adjacent different temperature zones. and reverse exit threshold The corresponding settings ensure that each temperature zone boundary location receives the corresponding hysteresis parameter support.

[0073] Step S22: Determine the low-to-medium hysteresis intervals of the low-temperature and medium-temperature zones by combining the boundary values ​​of the low-temperature and medium-temperature zones, the forward entry threshold, and the reverse exit threshold.

[0074] In this step, the low-to-medium hysteresis range in the low-temperature and medium-temperature regions is: , This represents the boundary value between the low-temperature and medium-temperature regions.

[0075] Step S23: Combine the boundary values ​​of the medium temperature zone and the high temperature zone, the forward entry threshold and the reverse exit threshold to determine the medium-to-high hysteresis interval of the medium temperature zone and the high temperature zone.

[0076] In this step, the medium-to-high hysteresis range in the medium-temperature and high-temperature regions is: , This represents the boundary value between the medium-temperature and high-temperature zones.

[0077] Step S3: Obtain the real-time operating temperature of the optical FP etalon in the frequency locking module. .

[0078] The controller acquires the actual operating temperature of the optical FP etalon through a second temperature sensor. .

[0079] Step S4: Determine the target temperature range based on the hysteresis range of the real-time operating temperature.

[0080] In this step, the adaptive frequency-locked laser needs to first complete the data retrieval preparation work, retrieve the real-time operating temperature data of the optical FP etalon previously acquired by the first temperature sensor from the storage module, and then compare the acquired real-time operating temperature value with the pre-calibrated upper and lower boundary values ​​of the hysteresis interval corresponding to the current preset temperature zone of the adaptive frequency-locked laser. In response to the relationship between the real-time operating temperature and the boundary value of the hysteresis interval corresponding to the preset temperature zone, the laser then strictly follows the preset hysteresis judgment logic that has been programmed in advance, and accurately executes the switching operation of the corresponding preset temperature zone operating state according to the comparison results. Finally, after completing the temperature zone operating state switching operation, the final target temperature zone corresponding to the current operating condition is determined.

[0081] Specifically, to provide a clear and unified execution basis for subsequent temperature zone determination and state switching, we first need to clearly define the three operating states involved in the entire adaptive laser temperature control process. State A0 corresponds to the low-temperature zone, state A1 to the medium-temperature zone, and state A2 to the high-temperature zone. After clearly defining all three operating states, the system will initiate the formal operation monitoring process, continuously collecting the current real-time operating temperature of the optical FP etalon through pre-deployed temperature acquisition devices. The system obtains real-time operating temperature data reflecting the operating conditions of the adaptive frequency-locked laser. Based on this real-time operating temperature data, and combined with the current temperature zone status of the adaptive frequency-locked laser, it sequentially completes the assignment determination operation between different temperature zones and the corresponding switching operation of the operating state according to the hysteresis judgment logic.

[0082] Specifically, when the hysteresis judgment logic enters the corresponding branch and the current system is in state A0, i.e., the low-temperature operating state, it will continuously update the collected real-time operating temperature data based on the collected real-time operating temperature data. The pre-set positive entry condition T for the low-temperature to medium-temperature zone according to control requirements LOW +△Z1 is used for comparison and logical judgment; when the real-time operating temperature T is detected... FP ≥T LOW +△Z1, confirm the real-time operating temperature of the acquired optical FP etalon. When the preset positive entry condition is reached or exceeded, it means that the preset threshold condition for positive entry from the low temperature region to the medium temperature region has been met. The adaptive frequency-locked laser will complete the state transition according to the established program logic, stably switching from the current state A0 low temperature region to state A1 medium temperature region. If confirmed by detection, the real-time operating temperature of the optical FP etalon is... If the preset positive entry condition is not met, or the preset threshold switching condition is not satisfied, the current state A0 low temperature zone remains unchanged, and no temperature zone state switching operation occurs during the entire control process.

[0083] When the system is currently in state A1, which is the medium temperature zone, since the medium temperature zone connects both the low temperature zone and the high temperature zone, threshold determination will be performed in both directions simultaneously.

[0084] On the one hand, the adaptive frequency-locked laser will continuously transmit the real-time operating temperature of the acquired optical FP etalon. The reverse exit condition T, which is set in advance according to the control requirements for the low-temperature-medium-temperature zone. LOW -△Z2 performs comparison and logical judgment; if the real-time operating temperature T is detected... FP ≤T LOW -△Z2, the optical FP standard's real-time operating temperature meets the preset threshold conditions for reversing from the medium temperature zone to the low temperature zone. The adaptive frequency-locked laser will complete the state transition according to the established program logic, and stably switch from the current state A1 medium temperature zone to the state A0 low temperature zone.

[0085] On the other hand, the adaptive frequency-locked laser will also continuously transmit the real-time operating temperature of the acquired optical FP etalon. The positive entry condition T of the medium-high temperature zone is set in advance according to the control requirements. HIGH +△Z1 is used for comparison and logical judgment. If the real-time operating temperature T is detected... FP ≥T HIGH+△Z1, when the real-time operating temperature of the optical FP standard meets the preset threshold condition for entering the high-temperature zone, the adaptive frequency-locked laser will complete the state transition according to the established program logic, and stably switch from the current state A1 medium temperature zone to the state A2 high temperature zone.

[0086] If the real-time operating temperature If the temperature zone is within the buffer range of the two hysteresis intervals and does not meet any of the above threshold conditions for temperature zone switching, the temperature zone in the current state A1 will remain unchanged, and no temperature zone state switching operation will occur during the entire control process.

[0087] When the system is currently operating in state A2, i.e., the high-temperature zone, it will continuously compare the real-time operating temperature of the optical FP etalon with the real-time data fed back by the temperature acquisition module. The threshold T for reversing the temperature control logic from the pre-set medium-high temperature zone exit is... HIGH -△Z2; If T is confirmed through comparison and testing FP ≤T HIGH -△Z2, if the real-time operating temperature of the optical FP etalon meets the preset threshold condition for reversing from the high-temperature zone to the medium-temperature zone, the system will complete the state transition operation according to the preset state transition logic, stably switching from the current state A2 (high-temperature zone) to state A1 (medium-temperature zone); if the comparison and detection confirms that the preset threshold condition is not met, i.e., the collected real-time operating temperature of the optical FP etalon... If the temperature remains within the threshold range corresponding to the high-temperature zone, the current state A2 high-temperature zone will remain unchanged, and no temperature zone state switching operation will occur during the entire temperature control process.

[0088] Step S5: Determine the target laser source to be locked to the current frequency.

[0089] In this step, the selected laser source is used as the target laser source.

[0090] For example, the first laser source is selected and operates in the low-temperature region.

[0091] Step S6: In the running parameter dataset, the frequency locking module corresponds to the optimal operating temperature of the optical FP etalon for the target laser source within the target temperature range. And combined with the real-time operating temperature of the optical FP etalon Determine temperature error and rate of temperature change .

[0092] The controller acquires the real-time operating temperature of the optical FP etalon through an integrated first temperature sensor. The optical FP etalon's current operating temperature data, after data acquisition and signal analog-to-digital conversion, is transmitted to the built-in temperature control logic module. The temperature control module then determines the actual operating temperature range of the target laser source based on pre-built hysteresis state machine rules, and subsequently retrieves the operating parameter dataset pre-stored by the controller. Within this range, the optimal operating temperature pre-calibrated by the corresponding frequency locking module within the specified temperature range is retrieved. For example, the optimal operating temperature of the frequency locking module corresponding to the first laser source in the low-temperature region is retrieved. Based on this, the temperature error between the currently acquired real-time operating temperature and the preset optimal operating temperature for this temperature range is calculated using pre-set calculation rules. It is important to emphasize that, in this step and the corresponding control method, the optimal operating temperature... This is just an example; other optimal operating temperatures may also apply.

[0093] When the calculated temperature error is positive, that is This indicates that the actual operating temperature of the frequency locking module is higher than the optimal operating temperature calibrated for that temperature range. Therefore, the operating temperature setpoint of the frequency locking module needs to be adjusted downwards to gradually bring the real-time operating temperature back to the optimal range. When the calculated temperature error is negative, i.e. This indicates that the actual operating temperature of the frequency locking module is lower than the optimal operating temperature calibrated for this temperature range. The operating temperature setting of the frequency locking module needs to be adjusted upwards to gradually bring the real-time operating temperature back to the optimal range. The larger the absolute value of the temperature error, the more serious the deviation of the actual operating temperature of the current frequency locking module from the preset optimal frequency locking point. In the subsequent temperature control adjustment process, the correction amplitude required will be greater, and the adjustment force of the controller output will also increase accordingly.

[0094] The rate of temperature change was then calculated. Where k is the current sampling time and k-1 is the previous sampling time, For a fixed sampling period, such as The calculated temperature change rate can intuitively characterize how fast the temperature error changes over time, and can also clearly reflect whether the overall temperature of the target laser source is rising or falling.

[0095] Step S7: Check temperature error and rate of temperature change Fuzzy reasoning and declarative processing were performed on all samples to determine the temperature correction amount. .

[0096] In this step, based on temperature error and rate of temperature change These two core control parameters are fuzzified to reduce the original temperature error. and rate of temperature change Each fuzzy inference is precisely mapped to a pre-designed and configured subset of fuzzy language. This fuzzy inference does not require a large amount of computing resources, making it ideal for long-term stable operation on low-power microcontroller chips with limited computing power.

[0097] Specifically, step S7 can be achieved through the following steps S71 to S75.

[0098] Step S71: Map the temperature error to the first fuzzy language subset.

[0099] In the current step S71, the temperature error that has already undergone normalization mapping processing is addressed. The variables are clearly divided into fuzzy subsets according to pre-designed rules. The entire partitioning scheme is logically clear and is divided into 5 clearly defined fuzzy linguistic values: negative large (NB1), negative small (NS1), zero (ZO1), positive small (PS1), and positive large (PB1). The specific physical meanings of each linguistic value are as follows: NB1 represents that the actual operating temperature of the current frequency locking module is much lower than the preset optimal operating temperature in this temperature zone; NS1 represents that the actual operating temperature of the current frequency locking module is slightly lower than the preset optimal operating temperature in this temperature zone; ZO1 represents that the actual operating temperature of the current frequency locking module is close to the preset optimal operating temperature in this temperature zone, and the temperature error is within the minimum acceptable range for the temperature control algorithm; PS1 represents that the actual operating temperature of the current frequency locking module is slightly higher than the preset optimal operating temperature in this temperature zone; PB1 represents that the actual operating temperature of the current frequency locking module is much higher than the preset optimal operating temperature in this temperature zone.

[0100] Step S72: Map the rate of temperature change to a second fuzzy language subset.

[0101] In this step, we target the temperature change rate that has already undergone normalized mapping. The variable, consistent with the previous method of classifying the temperature error variable, uses a unified classification logic and hierarchical rules. Its fuzzy subset is also clearly defined, resulting in a clear and logically consistent classification scheme. It is divided into five clear fuzzy linguistic values: negative large (NB2), negative small (NS2), zero (ZO2), positive small (PS2), and positive large (PB2). The physical meaning of each linguistic value is as follows: NB2 represents that the currently acquired and calculated temperature error is rapidly increasing in the negative direction, corresponding to the current actual operating temperature of the frequency locking module being in a state of rapid decrease; NS2 represents that the currently acquired and calculated temperature error is positive... The value of ZO2 indicates that the temperature error is slowly increasing in the negative direction, corresponding to a slow decrease in the actual operating temperature of the frequency locking module; ZO2 indicates that the temperature error calculated by the current acquisition is basically stable, with the overall fluctuation range within the extremely small acceptable range for the temperature control system, corresponding to a stable actual operating temperature of the frequency locking module that no longer shows significant rises or falls; PS2 indicates that the temperature error calculated by the current acquisition is slowly increasing in the positive direction, corresponding to a slow increase in the actual operating temperature of the frequency locking module; PB2 indicates that the temperature error calculated by the current acquisition is rapidly increasing in the positive direction, corresponding to a rapid increase in the actual operating temperature of the frequency locking module.

[0102] Step S73: Establish a fuzzy control model based on the first and second fuzzy language subsets.

[0103] A fuzzy control model is established using a two-dimensional rule-based approach, based on the first and second fuzzy language subsets.

[0104] The fuzzy control model is illustrated in Table 1 below.

[0105] Table 1. Fuzzy Language Input / Output Table

[0106] Step S74: Determine the fuzzy control quantity based on the fuzzy control model .

[0107] Based on the temperature error obtained after fuzzification processing With temperature change rate The system uses a fuzzy language to directly query the two-dimensional fuzzy control model pre-stored in the internal storage unit of the temperature controller. The fuzzy inference process is completed quickly through direct table lookup. The entire inference process employs a lightweight table-lookup inference scheme, eliminating the need for complex matrix operations with high computational demands. Compared to traditional fuzzy inference schemes, it requires less computing power and storage space from the embedded controller, consumes fewer controller hardware resources during operation, has lower overall computational latency, and its response speed fully meets the real-time temperature regulation requirements of temperature control systems in various laser processing and laser output scenarios. Finally, the corresponding matching fuzzy control quantity is output from the entire inference process. According to this fuzzy subset partitioning rule, the output fuzzy control quantity Using the same input variable partitioning logic as described above, the input variables are divided into five distinct fuzzy linguistic values: negative large (NB3), negative small (NS3), zero (ZO3), positive small (PS3), and positive large (PB3). The specific physical meanings of each linguistic value are as follows: NB3 corresponds to a significant reduction in the temperature setpoint to quickly bring back the excessively high operating temperature; NS3 corresponds to a slight reduction in the temperature setpoint to fine-tune the current operating temperature; ZO3 corresponds to no need to correct the original temperature setpoint, simply maintaining the original temperature setpoint is sufficient to meet the temperature control requirements; PS3 corresponds to a slight increase in the temperature setpoint to fine-tune the current excessively low operating temperature; and PB3 corresponds to a significant increase in the temperature setpoint to quickly compensate for the excessively low operating temperature.

[0108] In one example, in the fuzzy control model constructed by the frequency locking module temperature, when the input temperature error... When the corresponding fuzzy linguistic value is negative (NB1), it means that the actual operating temperature of the frequency locking module is much lower than the preset target temperature, and the deviation has exceeded the allowable range. When the input temperature change rate ec corresponds to a negative fuzzy linguistic value (NB2), it means that the current real-time operating temperature is rapidly decreasing towards a temperature lower than the target temperature, and the temperature will continue to deviate rapidly from the preset range. When the final output fuzzy control quantity is positive (PB3), the temperature setpoint needs to be significantly increased to achieve a rapid temperature compensation operation to increase the operating temperature of the frequency locking module and pull the temperature of the adaptive frequency locking laser back to the preset target range.

[0109] Temperature error The corresponding fuzzy linguistic value is negative (NS1), indicating that the current actual operating temperature of the frequency locking module is slightly lower than the preset target temperature, but the overall deviation is still within a small range and has not exceeded the allowable deviation threshold of temperature control. The input temperature change rate ec corresponds to a negative fuzzy linguistic value (NB2), indicating that the current real-time operating temperature is slowly changing towards a temperature lower than the target temperature, and the trend of temperature deviation from the target range has already appeared, but the overall rate of change is slow. When the corresponding fuzzy control quantity output is positive (PS3), it is necessary to slightly increase the temperature setpoint, and adjust the temperature by fine-tuning the temperature control parameters to gradually increase the operating temperature of the frequency locking module and make it smoothly return to the preset target temperature range.

[0110] Temperature error input this time The corresponding fuzzy linguistic value is zero, i.e., temperature error. A reading close to 0 (ZO1) indicates that the actual operating temperature of the frequency locking module is very close to the preset target temperature, which fully meets the control requirements and is in an ideal operating state with stable temperature. The input temperature change rate ec remains unchanged (ZO2), indicating that the overall trend of the current operating temperature of the frequency locking module is stable, without any tendency to shift towards higher or lower temperatures. According to the pre-established fuzzy inference rules, the final output fuzzy control quantity corresponding to this inference is 0. No adjustment is required to the existing temperature setting parameters; it is only necessary to maintain the steady-state operation of the current system.

[0111] Temperature error The corresponding fuzzy language value is positive (PS1), indicating that the actual operating temperature of the frequency locking module is slightly higher than the preset target temperature, showing a positive deviation from the target temperature. However, the overall deviation is still within a small range and far from exceeding the maximum allowable deviation threshold of the temperature control system; temperature change rate. The corresponding fuzzy language value is positive small (PS2), which means that the current temperature error is increasing slowly towards the high temperature direction. The trend of temperature deviating from the target range has been shown, but the change is very gradual: it is deduced according to the pre-established fuzzy inference rules; when the output fuzzy control quantity is negative small (NS3), it is only necessary to slightly lower the current temperature setpoint, and there is no need to make a large adjustment to the temperature control parameters.

[0112] It should be emphasized that the above examples are only illustrative of four of the twenty-five possible outcomes in the fuzzy control model during the fuzzy inference process. Other outcomes can be found in the table above.

[0113] Step S75: Perform weighted average defuzzification processing on the fuzzy control quantity to obtain the temperature correction quantity. .

[0114] After performing weighted averaging and declarative processing on the fuzzy control quantity output by fuzzy inference, the final temperature correction quantity used for temperature adjustment can be obtained. Based on the operating temperature zone of the frequency locking module identified by the hysteresis state machine, pre-stored and set fuzzy control weight coefficients are retrieved. The retrieved weight coefficients need to match the temperature control sensitivity and thermal inertia characteristics corresponding to different temperature zones: the low temperature zone has greater overall thermal inertia and slower temperature control response speed, so a smaller correction weight is matched; the medium temperature zone is the normal operating reference temperature zone of the frequency locking module, with stable characteristics, so a medium-sized correction weight is matched; the high temperature zone has higher sensitivity to temperature changes and is prone to oscillations during adjustment, so a moderate-sized correction weight is matched.

[0115] Step S8: Call the fuzzy control weight coefficients corresponding to the frequency locking module in the target temperature range from the running parameter dataset, and adjust the temperature correction amount. The weighted values ​​are then added to the optimal operating temperature. Determine the temperature setpoint .

[0116] This step can be achieved through the following steps S81 and S82.

[0117] Step S81: Determine the target fuzzy control weight coefficient corresponding to the target temperature zone; the target fuzzy control weight coefficient is either the first fuzzy control weight coefficient or the second fuzzy control weight coefficient.

[0118] In this step, if the target laser source is the first laser source, the first fuzzy control weight coefficient in the target fuzzy control weight is determined by combining the first laser source and the target temperature; if the target laser source is the second laser source, the second fuzzy control weight coefficient in the target fuzzy control weight is determined by combining the second laser source and the target temperature range.

[0119] Step S82: Adjust the temperature correction amount Multiply by the target fuzzy control weight coefficient to obtain the weighted correction amount, and then add the weighted correction amount to the optimal operating temperature. To determine the temperature setpoint .

[0120] In this step, the final temperature setpoint of the controller is obtained by adding a correction value weighted by a fuzzy algorithm based on the current optimal temperature of the temperature range. . This is the temperature setpoint after intelligent tuning using a fuzzy algorithm with dual inputs of error and error change rate.

[0121] Step S9: Drive the frequency locking module according to the temperature setpoint.

[0122] This step can be achieved through the following steps S91 and S92.

[0123] Step S91: Set the temperature setting value Convert to corresponding analog voltage .

[0124] In this digital-to-analog conversion step, the controller receives the digitized target temperature setpoint output and converts it via the DAC (Digital-to-Analog Converter) interface integrated on the control board. The originally discrete digital temperature setting signal is converted into a continuous analog voltage that corresponds one-to-one with the value of the digital quantity. The converted stable analog voltage signal is then transmitted to the dedicated temperature control circuit of the frequency locking module, providing a signal basis for subsequent temperature drive adjustments.

[0125] Step S92: Based on the analog voltage-driven frequency-locking temperature control circuit and Peltier cooling element, the real-time operating temperature of the optical FP etalon is adjusted to the set temperature value. Due to the influence of ambient temperature, the optimal operating temperature point of the frequency-locking module will drift due to the thermal stress of the optical FP etalon and the deformation of the cavity expansion mirror frame. If a single temperature is fixed without adaptive adjustment, the frequency-locking error will increase and the frequency jitter will intensify after the temperature deviates from the optimal operating point, which may lead to mode skipping, loss of lock, and linewidth broadening. In addition, the dual-frequency laser outputs different frequencies, and each frequency corresponds to an independent set of optimal temperature matching conditions. Therefore, the optimal operating temperature point will inevitably be different after switching frequencies. If the original temperature is used after frequency switching, it is impossible to quickly enter the frequency-locking steady state. The frequency-locking accuracy, stability, and consistency of dual-frequency switching deteriorate under a fixed temperature.

[0126] The temperature control circuit of the frequency-locking module has been introduced, and a hardware circuit for analog PI regulation has been built, resulting in extremely fast temperature closed-loop control response and strong real-time performance. However, since the P and I parameters are fixed, optimal dynamic response and steady-state accuracy can only be achieved within a certain optimal temperature range. When deviating from the optimal temperature range, the sensitivity and thermal conductivity characteristics of the system temperature control change. For example: in the low-temperature range, the thermal response is slow and the sensitivity is low; in the medium-temperature range, the characteristics are close to linear, matching the original fixed PI; in the high-temperature range, the heat generation / dissipation rate is fast, the sensitivity is high, and it is prone to overshoot and oscillation. Since the hardware PI cannot be modified in real time, direct use will result in slow convergence at low temperatures, unstable frequency locking due to overshoot at high temperatures, and poor consistency across the entire temperature range.

[0127] In step S92, the temperature control circuit performs hardware PI regulation based on preset proportional-integral control parameters, outputs a drive duty cycle that meets the current temperature error requirements, drives the Peltier cooling element connected to the temperature control loop, such as a TEC semiconductor cooling chip, to quickly adjust the temperature of the optical FP etalon by cooling or heating, so that it quickly approaches and stabilizes at the optimal operating temperature obtained in the pre-calibration, and finally achieves high-precision temperature control effect for the optical FP etalon during frequency-locked operation.

[0128] Figure 5 This is a schematic diagram of the structure of a frequency locking module temperature control circuit provided in an embodiment of this application.

[0129] In one specific implementation, the high-precision temperature control function in step S92 can be achieved through closed-loop control using a specially designed integrated frequency-locked temperature control circuit. The specific circuit connection and operating logic are as follows: Figure 5 As shown in the diagram, the frequency-locked temperature control circuit, based on its circuit structure, mainly consists of two parts: a temperature control circuit for signal acquisition and processing, and a temperature drive circuit for power output. These two parts work together to complete closed-loop temperature control. In the temperature control circuit section responsible for signal processing, a high-precision operational amplifier receives stable setting commands sent from the main control unit. Based on the currently selected first or second laser source, the target set temperature value of the corresponding frequency locking module is matched. This signal is amplified by an operational amplifier according to a predetermined gain, and finally outputs a stable temperature set voltage value corresponding to the target temperature. The second temperature sensor, such as a thermistor NTC, is integrated within the frequency locking module and is directly connected to a constant current source stabilization bias circuit specifically designed for it. This constant current source stabilization bias circuit provides the NTC with a stable operating current reference that is unaffected by ambient temperature fluctuations, external power supply voltage disturbances, and individual component parameter differences. Ultimately, it can output a high-precision temperature detection voltage that accurately corresponds to the current actual operating temperature of the frequency locking module. .

[0130] Temperature setting voltage value After being led out from the signal output terminal, it is connected to the first resistor R1 of the voltage divider network, and the other end of the second resistor R2 of the voltage divider network is connected to a pre-calibrated reference voltage network. The reference voltage value output by the reference voltage network For a specific reference operating temperature, such as a typical reference temperature of 25°C, the output voltage at the node between resistors R1 and R2 can be calculated to be... Where R1 is the actual resistance value of resistor R1, R2 is the actual resistance value of resistor R2, and R1=R2. The voltage output from this node is ultimately connected to the non-inverting input of operational amplifier U1B; this completes the acquisition of the real-time operating temperature detection voltage. The voltage is then connected to the inverting input of operational amplifier U1B via voltage divider and current limiting resistor R3. The output of operational amplifier U1B is also fed back to its own inverting input via feedback resistor R4, forming a closed-loop differential amplifier structure. Finally, the output voltage of U1B is... To satisfy the derivation relationship, the resistance values ​​of resistors R3 and R4 in this circuit design are also set to be equal to ensure the differential amplifier gain matching design requirements.

[0131] The voltage output at the output terminal of operational amplifier U1B It will be consistent with the pre-calibrated reference voltage. The input signals are connected to the input terminals of a proportional amplifier, which amplifies them proportionally. The output of the proportional amplifier is directly connected to the corresponding input terminal of a bias adder, and the final output voltage of the proportional amplifier is... The relationship is satisfied, where P is the preset amplification parameter of the proportional amplifier; simultaneously, the voltage output at the output terminal of operational amplifier U1B... It will also be consistent with the pre-calibrated reference voltage. The input terminals of the error integrator and resistors R8 and R9 are connected together. The output terminal of the error integrator is connected to the corresponding input terminal of the biased adder via resistors R8 and R9. The final output voltage of the error integrator is... The corresponding relationship is satisfied, where I is the preset integration parameter value of the integration module.

[0132] The resistor divider network formed by resistors R5, R6, R7, and R8 determines the quiescent operating point of the PI controller. Reference voltage. Connect to the input of the biased adder, the adder output ,in Adder output Connect to follower U2A output Adder output With reference voltage (Through resistor R10) connected to differential amplifier U1A, output ; and Entering the first comparator, and Entering the second comparator, where and These are the upper and lower limits for regulating the temperature of the frequency locking module; the comparator output... , This is the heating / cooling drive voltage for the frequency lock module drive circuit.

[0133] Figure 6 This is a schematic diagram of the structure of a frequency locking module temperature driving circuit provided in an embodiment of this application.

[0134] In a specific implementation, see Figure 6 As shown, and The relevant voltage signal enters the frequency locking module's temperature drive circuit for dual closed-loop control, achieving precise temperature regulation of the frequency locking module. Reference temperature voltage. and temperature feedback signal voltage The voltages are fed into the non-inverting input of the non-inverting summing amplifier U2B via resistors R12 and R15. The circuit achieves a weighted summation of the two input voltages by adjusting the resistance ratio of resistors R12, R13, R14, and R15, ultimately outputting a weighted summation output voltage that meets the control requirements. Among them, resistors R12 and R14 have the same resistance value, resistors R13 and R15 have the same resistance value, and n is a pre-set constant.

[0135] Weighted summation output voltage The voltage enters the inverting input of U3B after passing through resistor R16, which is the temperature setting target voltage of the frequency locking module. The voltage also passes through resistor R17 to the inverting input of U3B. Capacitor C1 and resistor R19 are connected in parallel between the output and inverting input of U3B, thus forming a non-inverting amplifier with low-pass filtering. The output voltage of this amplifier can be expressed as... Similarly, The other signal also follows this amplification relationship, where A is a pre-set error amplification factor. In this process, the operational amplifier completes the (target value - feedback value) error amplification processing in the heating / cooling direction, amplifying the temperature error signal proportionally to provide a control signal that meets the level requirements for the subsequent power drive circuit.

[0136] The output of U3B is connected to the non-inverting input of U4A and the inverting input of U4B, respectively. The output of U3A is connected to the inverting input of U4A and the non-inverting input of U4B, respectively. This cross-connection method allows the error signal to enter a preset amplification channel. U4A amplifies the received signal, enhancing the output cooling temperature error signal. The U4B amplifies the received signal to enhance the output heating temperature error signal. It enables separate amplification output of error signals for both cooling and heating. The amplified cooling error signal is connected to the first gate of the gate driver chip U5 via the current-limiting resistor R25. The amplified heating error signal is connected to the second gate of the gate driver chip U5 through the current limiting resistor R24, providing a control level signal that meets the driving requirements for the power output of the subsequent gate driver chip.

[0137] The gate driver chip U5, together with transistors Q1 and Q2, forms two independent half-bridge driver units, thereby enabling bidirectional control of the magnitude and direction of the TEC current.

[0138] In heating mode, the circuit turns on only transistor Q1 in the upper half-bridge and turns off transistor Q2 in the lower half-bridge; in cooling mode, the circuit turns on only transistor Q2 in the lower half-bridge and turns off transistor Q1 in the upper half-bridge. The heating and cooling drive circuits are completely independent, and there will be no signal crosstalk problem during operation.

[0139] During operation, transistors Q1 and Q2 always operate in the variable resistance region of the MOSFET, allowing them to directly limit the current in the TEC circuit through changes in their operating states, thus achieving stepless current regulation. The operating current flowing through the TEC... Size, or The current will further flow through the current sampling resistor R30, generating a feedback voltage across the sampling resistor that is proportional to the current magnitude. The feedback voltage is fed back to the operational amplifier U2B, forming a complete current closed-loop control circuit, which can limit and stabilize the operating current of the TEC in real time and quickly.

[0140] The frequency-locked temperature control module adopts a dual-closed-loop cascaded control architecture of an outer temperature loop and an inner current loop. The two control loops work collaboratively to achieve precise and stable temperature control. The outer temperature loop uses the system's heating or cooling command as the setpoint and dynamically adjusts the output parameters based on the deviation between the current temperature signal and the setpoint, ultimately achieving high-precision control of the target temperature. The inner current loop, through current sampling resistors installed in the loop, collects the current flowing through the TEC cooler in real time and converts the collected current signal into a feedback voltage, which is then introduced into the control input to form a negative feedback regulation mechanism. This not only quickly stabilizes the operating current of the entire loop but also directly limits the maximum output current of the loop at the hardware level, preventing overcurrent damage to components. The frequency-locked temperature control module designed in this embodiment significantly improves the overall temperature control accuracy and effectively reduces the steady-state error of temperature control through the collaborative control of the dual-closed-loop architecture, ultimately comprehensively improving the constant temperature control accuracy and long-term operational stability of the entire laser system.

[0141] Figure 7 This is a block diagram of a frequency locking module control algorithm provided in an embodiment of this application.

[0142] Among some feasible implementation methods, see Figure 7As shown, the temperature setpoint voltage uset(t) issued by the controller is subtracted from the real-time operating temperature feedback voltage uact(t) converted from the operating temperature of the optical FP etalon acquired in real time by the NTC at the summation node to obtain the temperature error signal. This error signal is fed into the proportional loop P and the integral loop I for proportional-integral operation and then superimposed. The superimposed result is subtracted from the reference voltage G provided by the reference voltage network at the summation node to generate the bidirectional adjustment control deviation ΔU(t). ΔU(t) is then superimposed with the reference voltage G to generate the cooling direction drive command G+ΔU(t) and the heating direction drive command G-ΔU(t). The two commands enter the inner current loop and are respectively compared with the positive current feedback voltage uI+(t) and the reverse current feedback voltage uI from the TEC current sampling. I Subtracting -(t) yields the upper half-bridge drive error signal Δu. TEC +(t) and the lower half-bridge drive error signal Δu TEC -(t), thereby limiting and stabilizing the TEC operating current in real time; two error signals drive the upper and lower half-bridges respectively: when cooling is needed, the upper half-bridge is turned on, and the TEC uses forward current to absorb heat and cool the etalon; when heating is needed, the lower half-bridge is turned on, and the TEC uses reverse current to release heat and heat the optical FP etalon. The upper and lower half-bridges work independently without crosstalk; after the TEC adjusts the temperature of the optical FP etalon, the NTC senses the temperature change and outputs a new uact(t) to feed back to the summing node and compare it with use(t) again. This cycle repeats until uact(t) approaches use(t), so that the temperature of the optical FP etalon is stabilized at the target operating point, thereby providing a long-term stable drift-free frequency reference for the adaptive frequency-locked laser.

[0143] In some feasible implementations, after step S9, the control method for the adaptive frequency-locked laser provided in this application embodiment may further include step S10.

[0144] Step S10: In response to the target laser source being switched, repeat the step of determining the target laser source to be locked to the current frequency.

[0145] In this way, after the laser source switching is completed, the adaptive frequency-locked laser can automatically re-enter the frequency-locking adjustment process without manual triggering of reset or restarting of the frequency-locking program. This can effectively shorten the waiting response time after switching, ensure the frequency stability of the output laser after switching between different laser sources, and adapt to the application scenario requirements of continuous alternating operation of multiple laser sources.

[0146] The wavelength of the first laser can be 1572.018 nm, and the wavelength of the second laser can be 1572.480 nm. After frequency stabilization, the wavelengths of the first and second lasers can be stabilized within the range of -0.002 nm to 0.004 nm for a relatively long period of time.

[0147] Figure 8 This is a flowchart illustrating the control method of the frequency locking module in a specific implementation provided in this application embodiment.

[0148] See Figure 8 As shown, in a specific implementation of this application embodiment, the control method of the frequency locking module may include the following steps S801 to S806.

[0149] Step S801: Divide the temperature range into three zones according to the applicable ambient temperature: low temperature zone, medium temperature zone, and high temperature zone.

[0150] Right now .

[0151] Step S802: System initialization, import running parameters .

[0152] Step S803: Select the laser source, the controller has a built-in hysteresis state machine, and determine the temperature zone and the temperature zone switching process.

[0153] Step S804: Based on the current temperature range, retrieve the corresponding optimal operating temperature value. The temperature setpoint is obtained by tuning it using a fuzzy intelligent control algorithm. .

[0154] Step S805: Transmit via DAC interface Convert to corresponding analog voltage It is transmitted to the temperature control circuit of the frequency locking module.

[0155] Step S806: The frequency locking module and temperature control module perform precise dual closed-loop adjustment of the outer temperature loop and the inner current loop, and monitor the actual temperature of the standard etalon in real time.

[0156] After step S806 is completed, in response to the switching of the target laser source, step S803 is repeated.

[0157] Specifically, in the control method of the frequency locking module provided in this application embodiment, the current temperature zone of the frequency locking module is first determined, and then the optimal operating temperature value stored in advance for the corresponding temperature zone is called. Next, the algorithm converts the calculated precise temperature error into fuzzy language quantities required for algorithm operation, and then performs three consecutive operations in sequence: fuzzification processing, fuzzy inference operation, and defuzzification, finally outputting the temperature correction amount. The obtained temperature correction amount is superimposed on the reference optimal operating temperature value, thus completing the dynamic tuning process of the temperature setpoint.

[0158] Input quantity: Actual operating temperature of the optical FP etalon And the optimal operating temperature corresponding to the current temperature range. The intermediate variable in the algorithm calculation process is the temperature error calculated by the controller. Temperature change rate The control parameters used are: pre-stored and set preset fuzzy weight coefficients. The algorithm's direct output value is the temperature correction amount used for temperature adjustment. The final output after tuning is: the temperature setpoint sent to the hardware PI control module. Among them, the optimal operating temperature This refers to the optimal operating temperature, which does not specify a particular temperature range.

[0159] It should be noted that, upon considering the specification and practicing the application disclosed herein, those skilled in the art will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0160] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The true scope is indicated by this application.

Claims

1. A control method for a frequency locking module, characterized in that, include: Construct a dataset of operating parameters for the frequency locking module; wherein, the dataset of operating parameters includes weighting coefficients, which are calculated by the frequency locking module based on different preset temperature zones; Determine the hysteresis interval between two adjacent preset temperature zones; the hysteresis interval includes a forward entry threshold and a reverse exit threshold. Obtain the real-time operating temperature of the optical FP etalon in the frequency locking module; Based on the hysteresis range in which the real-time operating temperature is located, the current target temperature range is determined; Identify the target laser source whose frequency is to be locked. In the running parameter dataset, the frequency locking module corresponds to the optimal operating temperature of the optical FP etalon in the target temperature range of the target laser source, and determines the temperature error and temperature change rate by combining the real-time operating temperature of the optical FP etalon; Both the temperature error and the temperature change rate are subjected to fuzzy reasoning and declarative processing to determine the temperature correction amount; The fuzzy control weight coefficients corresponding to the frequency locking module in the target temperature zone in the running parameter dataset are called to weight the temperature correction amount, and the weighted correction amount is superimposed on the optimal operating temperature to determine the temperature set value. The frequency locking module is driven according to the temperature setpoint to adjust the real-time operating temperature of the optical FP etalon to the temperature setpoint.

2. The control method for the frequency locking module according to claim 1, characterized in that, Construct the runtime parameter dataset for the frequency locking module, including: The operating parameter dataset includes a first reference temperature set corresponding to the frequency locking module and the first laser source, a second reference temperature set corresponding to the frequency locking module and the second laser source, a first weighting coefficient set corresponding to the first reference temperature set, and a second weighting coefficient set corresponding to the second reference temperature set. The first reference temperature set includes the optimal operating temperatures of the first laser source corresponding to the frequency locking module in the low-temperature, medium-temperature, and high-temperature regions, respectively; the second reference temperature set includes the optimal operating temperatures of the second laser source corresponding to the frequency locking module in the low-temperature, medium-temperature, and high-temperature regions, respectively. The first set of weighting coefficients includes the first fuzzy control weighting coefficients corresponding to the low temperature region, the medium temperature region, and the high temperature region, and the second set of weighting coefficients includes the second fuzzy control weighting coefficients corresponding to the low temperature region, the medium temperature region, and the high temperature region.

3. The control method for the frequency locking module according to claim 2, characterized in that, Determining the hysteresis interval between two adjacent preset temperature zones includes: Set the forward entry threshold and the reverse exit threshold; The low-to-medium hysteresis intervals of the low-temperature zone and the medium-temperature zone are determined by combining the boundary values ​​of the low-temperature zone and the medium-temperature zone, the forward entry threshold, and the reverse exit threshold; The medium-high hysteresis interval of the medium-temperature zone and the high-temperature zone is determined by combining the boundary values ​​of the medium-temperature zone and the high-temperature zone, the forward entry threshold, and the reverse exit threshold.

4. The control method for the frequency locking module according to claim 3, characterized in that, Based on the hysteresis range of the real-time operating temperature, the corresponding target temperature range is determined, including: In response to the relationship between the real-time operating temperature and the boundary value of the hysteresis interval corresponding to the preset temperature zone, the preset temperature zone is switched to obtain the corresponding target temperature zone.

5. The control method for the frequency locking module according to claim 4, characterized in that, Both the temperature error and the temperature change rate are subjected to fuzzy reasoning and declarative processing to determine the temperature correction amount, including: Map the temperature error to a first fuzzy language subset; Map the temperature change rate to a second fuzzy language subset; A fuzzy control model is established based on the first fuzzy language subset and the second fuzzy language subset; The fuzzy control quantity is determined based on the fuzzy control model. The fuzzy control quantity is subjected to weighted average clarification processing to obtain the temperature correction quantity.

6. The control method for the frequency locking module according to claim 5, characterized in that, The temperature correction amount is weighted and then added to the optimal operating temperature to determine the temperature setpoint, including: Determine the target fuzzy control weight coefficient corresponding to the target temperature zone; the target fuzzy control weight coefficient is either the first fuzzy control weight coefficient or the second fuzzy control weight coefficient. The temperature correction amount is multiplied by the target fuzzy control weight coefficient to obtain the weighted correction amount, and the weighted correction amount is added to the optimal operating temperature to determine the temperature setpoint.

7. The control method for the frequency locking module according to claim 6, characterized in that, The frequency locking module is driven according to the temperature setpoint to adjust the real-time operating temperature of the optical FP etalon to the temperature setpoint, including: Convert the temperature setpoint into a corresponding analog voltage; The frequency-locking temperature control circuit and Peltier cooling element of the frequency-locking module are driven by the analog voltage to adjust the real-time operating temperature of the optical FP etalon to the set temperature value.

8. The control method for the frequency locking module according to claim 1, characterized in that, The control method for the frequency locking module further includes: In response to the target laser source being switched, the step of determining the target laser source to be locked to the current frequency is repeated.

9. An adaptive frequency-locked laser, characterized in that, The adaptive frequency-locking laser, using the control method of the frequency-locking module as described in any one of claims 1-8, comprises: The first laser source is configured to output the first laser; A second laser source is configured to output a second laser; the first laser and the second laser have different frequencies. A dual-frequency laser switching unit is connected at one end to the first laser source and the second laser source respectively, and is configured to switch between the first laser and the second laser to output the target laser. The frequency locking module, connected to the other end of the dual-frequency laser switching unit, is configured to lock the frequency of the target laser. A laser frequency detection circuit, connected to the frequency locking module, is configured to acquire the optical signal of the target laser after it passes through the frequency locking module and convert it into an electrical signal output. A laser frequency control module, connected to the first laser source and the second laser source respectively, is configured to adjust the output frequency of the laser from the target laser source; The controller is connected to the frequency locking module, the laser frequency detection circuit, and the laser frequency control module, respectively.

10. The adaptive frequency-locked laser according to claim 9, characterized in that, The adaptive frequency-locked laser also includes an isolation coupler and an amplification stage; The frequency locking module includes an optical FP etalon, a first photodetector, a second photodetector, a first temperature sensor, a second temperature sensor, a frequency locking temperature control circuit, and a Peltier cooling element. The first port of the isolation coupler is connected to the dual-frequency laser switching unit, and the second port of the isolation coupler is connected to the optical FP etalon. The first photodetector is connected to the laser frequency detection circuit; The other end of the optical FP standard is connected to the second photodetector, and the end of the second photodetector away from the optical FP standard is connected to the laser frequency detection circuit. The first temperature sensor is connected to the controller, and the second temperature sensor is connected to the Peltier cooling element and the frequency-locked temperature control circuit respectively; the frequency-locked temperature control circuit is also connected to the controller and the Peltier cooling element respectively. The third port of the isolation coupler is connected to the amplification stage.

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