Solid laser frequency stabilization control method and system based on multi-parameter cooperative feedback

Abstract

The application provides a solid laser frequency stabilization control method and system based on multi-parameter cooperative feedback, relates to the technical field of optoelectronic device manufacturing, collects solid laser multi-parameter operation data, selects basic frequency stabilization or channel identification according to frequency deviation and operation state, determines control response quantity through laser crystal temperature control channel and pump current channel when the identification condition is met, determines compensation capacity and distribution proportion in combination with residual regulation capacity of each channel, and then distributes frequency compensation quantity to implement cooperative frequency stabilization, the application realizes cooperative compensation and dynamic frequency stabilization control under the change of multiple influencing factors through online trial identification, residual regulation capacity evaluation and cooperative compensation constrained by channel capacity, solves the problem that it is difficult to adapt to the actual regulation capacity of the current control channel when multiple operation parameters change, and distributes frequency compensation tasks according to actual compensation capacity, thereby improving the adaptability and operation safety of solid laser frequency stabilization control.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device manufacturing technology, and in particular to a method and system for frequency stabilization control of solid-state lasers based on multi-parameter collaborative feedback. Background Technology

[0002] With the development of laser technology, solid-state lasers, due to their compact structure, stable output, and wide applicability, have been widely used in precision measurement, optical communication, laser processing, and scientific research. During the operation of a solid-state laser, the stability of its output frequency is a crucial factor affecting its performance. Its stability is closely related to the internal temperature state of the laser, the characteristics of the laser crystal structure, and the operating state of the optical components. To improve the frequency stability of solid-state lasers, existing technologies mainly employ passive and active frequency stabilization methods. Passive stabilization reduces the impact of temperature changes on frequency output by optimizing the laser structure design and utilizing material properties. Active stabilization collects the laser's operating parameters and adjusts temperature, current, or other control parameters according to these changes to achieve stable control of the laser output frequency. As solid-state lasers develop towards higher precision, higher stability, and miniaturization, higher demands are placed on the frequency stability control capabilities during laser operation. Improving the frequency stability of solid-state lasers under different operating environments has become an important research direction in the field of solid-state laser control.

[0003] For example, Chinese invention patent application CN117543328A discloses a frequency stabilization method and system for a solid-state microchip laser, which includes: real-time acquisition of the current temperature inside the solid-state microchip laser; generation of a voltage signal based on the current temperature; processing of the voltage signal based on a fuzzy adaptive tuning PID algorithm to output a temperature adjustment signal; and temperature control of the solid-state microchip laser based on the temperature adjustment signal.

[0004] For example, Chinese invention patent CN119581986B discloses a control method for an adjustable pulse waveform solid-state laser, which includes: constructing a solid-state laser state monitoring model by acquiring the output power information, external environment information, optical component aging information, and control response information of the solid-state laser; evaluating the actual operating state of the solid-state laser; effectively identifying potential fault hazards in the solid-state laser; and when potential fault hazards exist in the solid-state laser, combining the temperature rise rate of the heat-affected zone, using a fuzzy PID control algorithm to dynamically control various parameters of the pulse.

[0005] The above-mentioned technology has at least the following technical problems: However, during the operation of a solid-state laser, changes in internal temperature, external environmental disturbances, and changes in device operating states can cause variations in the laser's operating parameters, leading to deviations in the laser's operating state and fluctuations in the laser output frequency, thus affecting the laser's output stability. Existing frequency stabilization control methods typically perform feedback adjustment on a single state parameter, lacking coordinated analysis and comprehensive control among different influencing factors. When multiple factors change simultaneously, it is difficult to determine the corresponding compensation amount in a timely and accurate manner, easily resulting in reduced frequency stability control accuracy and affecting the long-term stable operation of the solid-state laser. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for frequency stabilization control of solid-state lasers based on multi-parameter collaborative feedback, so as to solve the problems that in the existing frequency stabilization process of solid-state lasers, a single control channel is difficult to adapt to different operating states, there is a lack of effective coordination between control channels, and the compensation capability is easily insufficient or exceeds the allowable range of operating parameters when the frequency deviation is large.

[0007] In a first aspect, the present invention provides a method for frequency stabilization control of a solid-state laser based on multi-parameter cooperative feedback, comprising: The system collects multi-parameter operating data during the operation of the solid-state laser, including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current, and determines the current frequency deviation based on the preset target frequency and frequency stability threshold.

[0008] Based on whether the frequency deviation reaches the preset frequency stability threshold and whether the current operating parameters are within the corresponding allowable range, it is determined whether to perform control channel identification. If the identification conditions are not met, the preset basic frequency stabilization adjustment is executed. If the identification conditions are met, the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel are tested respectively, and the corresponding control response quantities are determined based on the laser output frequency, laser crystal temperature, piezoelectric drive voltage, and pump current before and after the test.

[0009] Based on the current laser crystal temperature, the distance between the piezoelectric driving voltage and pump current and their corresponding allowable ranges, as well as the control response, the frequency compensation capabilities of the three control channels are determined, and the frequency compensation allocation ratio is determined.

[0010] The total frequency compensation requirement is determined based on the frequency deviation and the frequency compensation capability of the three control channels. The laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment are determined according to the frequency compensation allocation ratio to coordinate the adjustment of the solid-state laser.

[0011] Secondly, the present invention provides a frequency stabilization control system for a solid-state laser based on multi-parameter cooperative feedback, comprising: The frequency stabilization state determination module is used to collect multi-parameter operating data during the operation of the solid-state laser, including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current, and determine the current frequency deviation based on the preset target frequency and frequency stabilization threshold.

[0012] The control channel identification module is used to determine whether to perform control channel identification based on whether the frequency deviation reaches the preset frequency stability threshold and whether the current operating parameters are within the corresponding allowable range. If the identification conditions are not met, the preset basic frequency stabilization adjustment is executed. If the identification conditions are met, the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel are tested respectively, and the corresponding control response is determined based on the laser output frequency, laser crystal temperature, piezoelectric drive voltage, and pump current before and after the test.

[0013] The frequency compensation capability determination module is used to determine the frequency compensation capability of the three control channels based on the current laser crystal temperature, the distance between the piezoelectric driving voltage and the pump current and the corresponding allowable range, as well as the control response quantity, and to determine the frequency compensation allocation ratio.

[0014] The collaborative frequency stabilization control module is used to determine the total frequency compensation requirement based on the frequency deviation and the frequency compensation capability of the three control channels, and to determine the laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment according to the frequency compensation allocation ratio, so as to coordinately adjust the solid-state laser.

[0015] The beneficial effects achieved by the technical solutions provided in the embodiments of the present invention include at least the following: (1) This invention monitors the laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric driving voltage, and pump current of a solid-state laser in a coordinated manner. Based on the frequency deviation and operating status, it adaptively selects the basic frequency stabilization control or control channel identification. The actual control response under the current operating status is obtained through online testing of the laser crystal temperature control channel and the pump current channel. Furthermore, the frequency compensation capability and compensation allocation ratio are determined by combining the current adjustable range of each channel. Coordinated adjustment is implemented under the condition of meeting the operating safety constraints. This realizes the dynamic utilization of the adjustment capability of different control channels and the reasonable allocation of frequency compensation. It solves the problems of limited adjustment capability of a single frequency stabilization channel of a solid-state laser, unstable frequency stabilization effect caused by changes in the control channel response under different operating states, and easy to exceed the allowable range of temperature, power, and pump current during the coordinated adjustment process. This improves the adaptability, stability, and operating safety of the frequency stabilization control of solid-state lasers.

[0016] (2) This invention applies a preset minimum sensing adjustment amount to the laser crystal temperature control channel and the pump current control channel respectively when the safe operating conditions are met, and determines the unit control response amount based on the laser output frequency before and after the test and the corresponding change in control parameters. This realizes the online identification of the actual frequency response capability of the two control channels, solves the problem that the control channel response characteristics of solid lasers change under different operating conditions and that it is difficult to accurately reflect the current adjustment effect by using fixed control parameters. At the same time, the influence of channel identification on the normal frequency stabilization process is reduced by the test effectiveness judgment and dynamic response recovery judgment.

[0017] (3) The present invention determines the maximum adjustable range of the two control channels based on the current laser crystal temperature, piezoelectric driving voltage, pump current and the distance between the corresponding allowable range boundary, and determines the maximum frequency compensation capability of each channel based on the unit control response obtained by online identification. Then, the frequency compensation allocation ratio is determined based on the maximum compensation capability of the two channels. This realizes the dynamic determination of how much the two control channels can still be adjusted and how much compensation task each channel undertakes based on the current operating status. It solves the problem that the fixed ratio allocation cannot reflect the current remaining adjustment space of the control channels and is prone to over-adjustment of a certain channel.

[0018] (4) This invention uses the current frequency deviation as the compensation requirement and compares it with the sum of the maximum frequency compensation capabilities of the two control channels. The smaller value is used to determine the actual total frequency compensation requirement. Then, it is converted into laser crystal temperature regulation, piezoelectric regulation and pump current regulation according to the compensation allocation ratio. The amplitude is limited in combination with the allowable range of each operating parameter. This achieves the matching between the frequency compensation requirement and the actual capability of the control channel. It solves the problem that when the frequency deviation is large, the theoretical compensation requirement may exceed the actual adjustable capability of the two control channels, resulting in the distortion of the control quantity allocation and the over-limit of the operating parameters during the adjustment process.

[0019] It should be understood that the content described in this section is not intended to identify key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A flowchart of a solid-state laser frequency stabilization control method based on multi-parameter collaborative feedback according to an embodiment of the present invention is shown. Figure 2This diagram illustrates the deviation threshold determination method in an embodiment of the present invention. Figure 3 This diagram illustrates the collaborative frequency stabilization logic block diagram in an embodiment of the present invention. Figure 4 This diagram illustrates parameter out-of-bounds identification in an embodiment of the present invention. Figure 5 This diagram illustrates the dual-channel compensation capability allocation in an embodiment of the present invention. Figure 6 This diagram illustrates the actual adjustment amount conversion in an embodiment of the present invention. Figure 7 The diagram shows a framework of a solid-state laser frequency stabilization control system based on multi-parameter collaborative feedback in an embodiment of the present invention. Detailed Implementation

[0022] Exemplary embodiments of the present invention will be described more fully below with reference to the accompanying drawings.

[0023] The accompanying drawings are illustrative of the invention and are not necessarily drawn to scale. Some block diagrams shown in the drawings may be functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in hardware modules or integrated circuits, or in networks, processors, or microcontrollers. Embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein. The features, structures, or characteristics described in this invention can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough description of embodiments of the invention. However, those skilled in the art will recognize that one or more specific details may be omitted when implementing the technical solutions of this invention. Sections, or other methods, components, devices, steps, etc., may be used to replace one or more specific details.

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0025] Example 1: A method for frequency stabilization control of solid-state lasers based on multi-parameter collaborative feedback is provided, such as... Figure 1The diagram shows a flowchart of a multi-parameter collaborative feedback-based frequency stabilization control method for solid-state lasers. The method includes: collecting multi-parameter operating data during the solid-state laser's operation; determining whether to use basic frequency stabilization adjustment or identify control channels based on frequency deviation and operating parameter status; when identification conditions are met, sequentially probing the laser crystal temperature, piezoelectric control channel, and pump current control channel to determine the corresponding control response quantities; further determining the frequency compensation capability and allocation ratio based on the current adjustable range of each channel; calculating the adjustment amount of each channel based on the current frequency deviation and executing collaborative frequency stabilization control; and then re-collecting operating parameters for the next round of adjustment.

[0026] It should be noted that the pump current's effect on the laser output frequency is mainly indirect, rather than directly changing the laser output frequency. Specifically, adjusting the pump current changes the pump power and the thermal load on the laser crystal, causing a change in the laser crystal's temperature state, which in turn causes changes in the laser crystal's refractive index and optical path. The change in optical path further leads to a change in the laser output frequency. Therefore, the pump current control channel achieves frequency regulation through a chain of action: changes in pump current lead to changes in thermal load, which in turn lead to changes in the laser crystal's temperature and optical properties, which in turn lead to changes in optical path, which in turn lead to changes in the laser output frequency. Since this process includes a thermal response component, the pump current's response to the laser output frequency is somewhat indirect and lag-dependent compared to direct piezoelectric regulation. At the same time, changes in pump current may also cause changes in laser output power and relative intensity noise. Therefore, when performing frequency coordinated regulation, the pump current control quantity must be appropriately constrained.

[0027] It should be added that there is thermal coupling between the laser crystal temperature control channel and the pump current control channel. Changes in the pump current will change the pump power and thermal load of the laser crystal, which may cause changes in the laser crystal temperature and further affect the laser output frequency. Therefore, the adjustment of the laser output frequency by the two control channels is not completely independent. In this embodiment, the unit control response of each control channel under the current operating state is obtained by identifying the control channel. After performing collaborative compensation, the laser output frequency and each operating parameter are reacquired and the frequency deviation is recalculated. The channel coupling effect generated by the previous round of adjustment is reflected in the new frequency deviation and changes in operating parameters. The next round of adjustment is entered based on the re-obtained frequency deviation, thereby correcting the compensation deviation caused by channel coupling through closed-loop iteration.

[0028] The solid-state laser in this embodiment includes a laser crystal, a frequency-doubling crystal, and a pump source. The laser crystal is connected to a temperature control module, the pump source is connected to a laser driver module, and the piezoelectric actuator is connected to a piezoelectric drive module. Temperature sensors are respectively installed at corresponding positions on the laser crystal and the frequency-doubling crystal. A frequency detection module and an optical power detection module are installed at the laser output end. The laser driver module has a pump current detection interface to obtain the current pump current, and the piezoelectric drive module has a piezoelectric drive voltage detection interface to obtain the current piezoelectric drive voltage. During the operation of the solid-state laser, the laser output frequency is obtained through the frequency detection module, and the laser crystal temperature and the frequency-doubling crystal temperature are obtained through the temperature sensors installed at corresponding positions on the laser crystal and the frequency-doubling crystal, respectively. The optical power detection module... The system acquires the laser output power and obtains the pump current and piezoelectric drive voltage through the pump current detection interface of the laser driver module and the piezoelectric drive voltage detection interface of the piezoelectric drive module, respectively. Based on the acquired laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, pump current, and piezoelectric drive voltage, the controller determines the current operating state and frequency deviation. Based on the frequency stabilization control results, it generates laser crystal temperature adjustment signals, pump current adjustment signals, and piezoelectric adjustment signals, respectively, and sends these signals to the temperature control execution module, laser driver module, and piezoelectric drive module to adjust the laser crystal temperature, pump current, and piezoelectric drive voltage, thereby achieving stable control of the laser output frequency.

[0029] Multi-parameter operating data of a solid-state laser is collected during its operation. The laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, pump current, and piezoelectric drive voltage are collected according to a preset sampling period. The laser output frequency is used to calculate the current frequency deviation. The laser crystal temperature, as the direct control object of the laser crystal temperature control channel, is used to characterize the impact of temperature regulation on the laser output frequency. The frequency doubling crystal temperature reflects the operating status of the frequency doubling crystal and serves as a safety constraint parameter during frequency stabilization. The laser output power is used to determine whether the laser output state is within the allowable range during temperature and pump current regulation. The pump current, as the direct control quantity of the pump current control channel, is used to regulate the pump state of the laser and serves as a safety constraint parameter during pump current control. The piezoelectric drive voltage, as the direct control parameter of the piezoelectric control channel, is used to regulate the drive state of the piezoelectric actuator. Each parameter forms a continuous sampling time series according to the same sampling period. The sampling time corresponding to each preset sampling period is used as the time reference. The operating parameters acquired by each acquisition channel at the corresponding sampling time are correlated to form multi-parameter operating data.

[0030] The preset sampling period is determined by first acquiring the actual sampling refresh periods corresponding to laser output frequency detection, laser crystal temperature detection, laser output power detection, and pump current detection. The maximum value among the actual sampling refresh periods corresponding to each detection channel is determined as the candidate sampling period. Then, the candidate sampling period is compared with the minimum sampling interval allowed by the controller. When the candidate sampling period is not less than the minimum sampling interval allowed by the controller, the candidate sampling period is determined as the preset sampling period. When the candidate sampling period is less than the minimum sampling interval allowed by the controller, the minimum sampling interval allowed by the controller is determined as the preset sampling period, and the determined preset sampling period is stored in the database.

[0031] Because the laser crystal temperature control channel has a slower thermal response compared to the piezoelectric control channel, the basic frequency stabilization control adopts a proportional-integral control method. During the equipment commissioning phase, a preset sampling period is determined based on the response time of the laser crystal temperature control channel. This ensures that the frequency response generated by temperature regulation can be reflected between adjacent sampling moments, avoiding repeated integral regulation before the temperature response has been formed. At the same time, parameters are screened by combining the step response calibration of the proportional coefficient and integral coefficient, as well as the stability conditions, overshoot, and allowable range of operating parameters, to ensure the stable operation of the basic frequency stabilization control under slow temperature response conditions.

[0032] Simultaneously, parameter calibration is performed before the solid-state laser is put into formal operation. First, the laser is placed in its rated operating state, with the rated output frequency as the target frequency. In this state, the temperature control quantity and pump current are gradually changed, and the changes in laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current are recorded respectively. The allowable range of each parameter is determined based on the parameter values ​​corresponding to frequency instability, temperature abnormality, output power abnormality, or drive current reaching the equipment protection boundary during the equipment commissioning process. Among them, the upper and lower boundaries of laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current that correspond to the equipment being able to operate continuously and stably are determined as the corresponding allowable ranges. The maximum frequency deviation that can maintain stable output under rated operating state is determined as the frequency stability threshold. The corresponding temperature control direction and pump current control direction are determined based on the laser output frequency change caused by the temperature control quantity and pump current change. After calibration, the target frequency, frequency stability threshold, allowable range of each parameter, and control direction are written into the database as preset parameters.

[0033] During operation, the above operating parameters are acquired according to the same sampling period, and a corresponding sampling timestamp is attached to each sampled value. Parameters with the same or corresponding sampling timestamps are associated to form multi-parameter operating data including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current, providing a unified data foundation for subsequent frequency deviation judgment, channel identification and coordinated frequency stabilization control.

[0034] The current frequency deviation is obtained by subtracting the target frequency from the laser output frequency. The sign of the frequency deviation represents the direction of the laser output frequency deviation relative to the target frequency, and the absolute value of the frequency deviation represents the degree of deviation of the current laser output frequency.

[0035] Figure 2 This is a schematic diagram of the deviation threshold determination in an embodiment of the present invention, including: determining whether to start frequency stabilization adjustment based on whether the frequency deviation exceeds a stable threshold. The diagram shows a frequency stabilization threshold band set according to the frequency deviation. When the frequency deviation exceeds the set threshold band due to external disturbances or changes in operating status, frequency stabilization adjustment is started according to the frequency deviation change trend, so that the frequency deviation re-enters the threshold band. The diagram shows deviation response curves under three different frequency deviation change processes to verify that frequency deviation suppression can be achieved.

[0036] When the absolute value of the frequency deviation is less than the frequency stability threshold determined in advance through experimental calibration during the equipment debugging phase, it is determined that the current laser output frequency is within the allowable stable range, and the solid-state laser is in a frequency stabilization state. At this time, the current temperature regulation signal, piezoelectric regulation signal and pump current regulation signal are not adjusted, and their current control values ​​are maintained to avoid additional disturbances to the already stable laser output frequency.

[0037] When the absolute value of the frequency deviation is greater than or equal to the frequency stabilization threshold, the absolute value of the frequency deviation at the corresponding moment is obtained according to a preset number of consecutive sampling periods, and the absolute values ​​of the frequency deviation at adjacent sampling moments are compared sequentially according to the sampling time. When the absolute value of the frequency deviation at each subsequent sampling moment is greater than the absolute value of the frequency deviation at the previous sampling moment, it is determined that the frequency deviation is in a state of continuous increase, indicating that the laser output frequency is further deviating from the target frequency. Channel identification is not performed, but basic frequency stabilization adjustment is adopted and cumulative timing begins. Because the trend of the current frequency deviating from the target frequency is still expanding, if an additional control channel is applied for probing at this time, the probing adjustment will be affected. The frequency changes generated by the section may overlap with the original frequency deviation trend, making it difficult to distinguish the actual control response generated by the trial adjustment. Therefore, it is not suitable to conduct control channel trials. If the frequency deviation continues to increase for a duration that reaches the preset maximum basic frequency stabilization duration during the basic frequency stabilization adjustment process, it indicates that the basic frequency stabilization adjustment has failed to effectively suppress the continuous expansion of the frequency deviation within the preset time. At this time, the basic frequency stabilization adjustment will be stopped and the control channel identification will be forcibly entered to obtain the actual control response of each control channel under the current operating state. If no control response can be obtained after forcibly entering the control channel identification, the control channel trial will be stopped and an alarm message will be generated.

[0038] The maximum basic frequency stabilization time is determined during the laser commissioning phase by conducting multiple basic frequency stabilization tests using the same proportional-integral control parameters and sampling period as the actual basic frequency stabilization control. The adjustment time from the start of basic frequency stabilization adjustment to the first time the absolute value of the frequency deviation enters the frequency stability threshold is recorded. The adjustment times of each test are arranged in ascending order, and the maximum adjustment time is taken as the maximum basic frequency stabilization time and stored in the database.

[0039] When the frequency deviation does not increase continuously, it indicates that the current frequency deviation is not in a state of continuous expansion. The currently collected laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current are compared with the corresponding preset allowable ranges. When all parameters are within the corresponding allowable ranges, it is determined that the current operating state meets the conditions for control channel identification; otherwise, it is determined that the identification conditions are not met, and the system switches to basic frequency stabilization adjustment to avoid applying trial adjustments when the frequency deviation continues to expand or the operating parameters are close to or exceed the safety boundary.

[0040] Figure 3The following is a block diagram of the collaborative frequency stabilization logic in this embodiment of the invention, including: determining whether the channel identification condition is met; if so, sequentially probing the laser crystal temperature control channel, the pump current control channel, and the piezoelectric control channel; wherein, the unit control response of the temperature control channel is obtained through probing the laser crystal temperature channel, the unit control response of the pump current control channel is obtained through probing the pump current channel, and the unit control response of the piezoelectric control channel is obtained through probing the piezoelectric control channel; after completing the probing of the three control channels, determining whether all three probings meet the corresponding validity criteria; when all three probings meet the validity criteria... If all attempts to establish a control channel fail, the current control channel identification process is exited and basic frequency stabilization is performed. When all three control channel attempts are successful, the maximum frequency compensation capability is determined based on the unit control response of each control channel. The compensation allocation ratio of each control channel is determined by combining the response speed and operating parameter constraints of each control channel. The laser crystal temperature adjustment, pump current adjustment, and piezoelectric adjustment are further calculated, and three-channel coordinated frequency stabilization is performed. After the coordinated frequency stabilization is completed, all operating parameters are re-acquired and the new frequency deviation is calculated. The next round of frequency stabilization control is then initiated based on the new frequency deviation.

[0041] The number of consecutive preset values ​​is determined based on the dynamic response time measured during the debugging phase and stored in the database. Specifically, under rated operating conditions, fixed adjustment values ​​calibrated offline by technicians are applied to the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel, respectively. Specifically, a temperature adjustment value is applied to the laser crystal temperature control channel, a piezoelectric adjustment value is applied to the piezoelectric control channel, and a pump current adjustment value is applied to the pump current control channel. The application time of the corresponding adjustment value is used as the response start time of the corresponding control channel. After applying the adjustment value, the laser output frequency is continuously sampled, and the laser output frequency at each sampling time is determined based on the absolute value of the difference between the laser output frequency and the target frequency at each sampling time. Optical output frequency deviation; when the laser output frequency deviation corresponding to three consecutive sampling times is less than the preset frequency stabilization threshold, the sampling time that first meets the condition is taken as the response stabilization time of the corresponding control channel. The time interval between the response stabilization time and the response start time is divided by the preset sampling period and rounded up to obtain the response sampling number of the laser crystal temperature control channel, the response sampling number of the piezoelectric control channel, and the response sampling number of the pump current control channel. The larger value among the response sampling number of the laser crystal temperature control channel, the response sampling number of the piezoelectric control channel, and the response sampling number of the pump current control channel is determined as the continuous preset number, and the determined continuous preset number is stored in the database.

[0042] The current laser output frequency is compared with the preset target frequency. When the frequency deviation is positive, that is, when the current laser output frequency is higher than the preset target frequency, the basic frequency compensation direction is determined to decrease the laser output frequency. When the frequency deviation is negative, that is, when the current laser output frequency is lower than the preset target frequency, the basic frequency compensation direction is determined to increase the laser output frequency. When the current laser output frequency is equal to the preset target frequency, no frequency compensation direction is generated. The basic frequency compensation direction determined in this way is used to subsequently determine the control direction of temperature adjustment and pump current adjustment.

[0043] During the equipment commissioning phase, a fixed-amplitude step adjustment, calibrated offline by technicians, is applied to the solid-state laser through the laser crystal temperature control channel, piezoelectric control channel, or pump current control channel. Multiple sets of basic frequency stabilization tests are conducted using different combinations of proportional and integral coefficients. The laser output frequency is continuously acquired, and the response time from the application of the step disturbance to the first time the absolute value of the frequency deviation reaches the frequency stability threshold, the maximum deviation of the frequency deviation relative to the target frequency, and the changes in various operating parameters are recorded. The maximum deviation from the target frequency after the frequency deviation first reaches the frequency stability threshold is defined as the overshoot. The overshoot is considered under the following conditions: frequency stability, overshoot not exceeding a preset overshoot threshold, laser crystal temperature, frequency doubling crystal temperature, and laser output power. Among the proportional coefficient combinations where both pump current and piezoelectric drive voltage do not exceed their respective allowable ranges, the combination of proportional coefficient and integral coefficient with the shortest response time is selected as the basic frequency stabilization control parameters. The calibration results are pre-stored in the database for use by the solid-state laser during operation. The proportional coefficient is used to determine the instantaneous compensation amount corresponding to the current frequency deviation, and the integral coefficient is used to determine the compensation amount based on the cumulative frequency deviation within a continuous sampling period. Specifically, the current frequency deviation is multiplied by the preset proportional coefficient, and the frequency deviations within a preset number of consecutive sampling periods before the current sampling time are accumulated and multiplied by the preset integral coefficient. The two results are then added together to obtain the basic frequency compensation amount, thereby ensuring that the basic frequency stabilization adjustment meets the frequency response speed requirements while avoiding significant oscillations during the adjustment process.

[0044] After determining the proportional and integral coefficients, basic adjustment allocation calibrations were performed on the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel. The adjustment ranges of the three control channels, as well as the laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current, were kept within their respective allowable ranges. Different basic compensation allocation ratios were set for the laser crystal temperature control channel, pump current control channel, and piezoelectric control channel, with the sum of the compensation allocation ratios of the three channels being 1. The basic frequency compensation was then allocated to the laser crystal temperature control channel, pump current control channel, and piezoelectric control channel according to the three compensation allocation ratios, and multiple sets of basic frequency stabilization adjustment tests were conducted. The frequency response time under each allocation ratio and the changes in each operating parameter during the frequency stabilization process were recorded. Among the allocation ratio combinations that met the frequency stability conditions and whose operating parameters did not exceed their respective allowable ranges, the allocation ratio combination with the shortest response time was selected as the optimal allocation ratio for basic frequency stabilization adjustment. The basic temperature compensation allocation ratio, basic piezoelectric compensation allocation ratio, and basic pump current compensation allocation ratio were pre-stored in a database for use during basic frequency stabilization adjustment.

[0045] During the basic frequency stabilization operation, the calculated basic frequency compensation is multiplied by the basic temperature compensation allocation ratio, the basic piezoelectric compensation allocation ratio, and the basic pump current compensation allocation ratio, respectively, to obtain the temperature frequency compensation for the laser crystal temperature control channel, the piezoelectric frequency compensation for the piezoelectric control channel, and the current frequency compensation for the pump current control channel.

[0046] Obtain the unit control response value obtained from the most recent control channel identification. Based on the unit control response value of each control channel, divide the corresponding frequency compensation value by the unit control response value to obtain the adjustment value of the corresponding control parameter. The unit control response value includes the frequency response direction of the corresponding control channel. Therefore, the positive or negative sign of the calculated control adjustment value simultaneously represents the adjustment direction of the corresponding control parameter.

[0047] When no control channel identification result is available, the temperature frequency compensation is divided by the frequency response coefficient of the laser crystal temperature control channel, the piezoelectric frequency compensation is divided by the frequency response coefficient of the piezoelectric control channel, and the current frequency compensation is divided by the frequency response coefficient of the pump current control channel to obtain the laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment.

[0048] During the solid-state laser manufacturing and assembly stage, the frequency response coefficients of the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel are determined by acquiring the factory-calibrated frequency response characteristics of these channels. Specifically, under preset operating conditions, the laser crystal temperature, piezoelectric driving voltage, and pump current are changed respectively, and the response relationship between the changes in the corresponding control parameters and the changes in the laser output frequency is recorded. The frequency response coefficient of the corresponding control channel is determined based on the frequency change caused by a unit change in the control parameters. Specifically, the frequency response coefficient of the laser crystal temperature control channel represents the change in laser output frequency caused by a unit change in laser crystal temperature, in Hz / ℃; the frequency response coefficient of the piezoelectric control channel represents the change in laser output frequency caused by a unit change in piezoelectric driving voltage, in Hz / V; and the frequency response coefficient of the pump current control channel represents the change in laser output frequency caused by a unit change in pump current. The change in laser output frequency is expressed in Hz / A. If the frequency response coefficient is positive, it means that increasing the control parameter will cause the laser output frequency to change in the positive direction, and decreasing the control parameter will cause the laser output frequency to change in the negative direction. If the frequency response coefficient is negative, it means that the frequency change caused by the change in the control parameter is opposite to the parameter adjustment direction. Therefore, based on the fundamental frequency compensation direction and the sign of the corresponding frequency response coefficients of the laser crystal temperature control channel and the pump current control channel, the adjustment direction of the two control channels is determined respectively, so that the frequency change direction generated by each control channel is consistent with the fundamental frequency compensation direction. The laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment are superimposed on the current temperature adjustment signal and the current pump current adjustment signal according to the corresponding control direction, thereby realizing the calculable conversion of the fundamental frequency compensation amount to the adjustment amount of the two control channels, and ensuring that the sum of the frequency compensation amounts undertaken by the two control channels is consistent with the fundamental frequency compensation amount.

[0049] When any of the operating parameters—laser crystal temperature, laser output power, or pump current—exceeds its corresponding allowable range, the corresponding control channel is determined based on the parameter exceeding the limit. Specifically, when the laser crystal temperature or frequency doubling temperature exceeds its allowable range, the laser crystal temperature control channel is designated as the recovery control channel; when the laser output power or pump current exceeds its allowable range, the pump current control channel is designated as the recovery control channel. The direction of recovery adjustment is determined based on the deviation of the exceeding operating parameter from its corresponding allowable range. Specifically, when the laser crystal temperature or frequency doubling temperature exceeds the upper allowable limit, the adjustment moves towards lowering the temperature; when the laser crystal temperature or frequency doubling temperature falls below the lower allowable limit, the adjustment moves towards raising the temperature. When the output power or pump current exceeds the upper limit of the allowable range, the pump current is adjusted to decrease. When the laser output power or pump current is below the lower limit of the allowable range, the pump current is adjusted to increase. Then, the corresponding temperature adjustment signal or pump current adjustment signal is gradually adjusted according to the preset adjustment step size. After each adjustment, the corresponding operating parameters are re-acquired until the parameters exceeding the limit are restored to the corresponding allowable range. After the over-limit recovery is completed, the temperature adjustment signal and pump current adjustment signal are limited according to the current laser crystal temperature, pump current, and the allowable range of laser crystal temperature and laser output power to prevent any operating parameter from exceeding the allowable range again after the adjustment. Finally, the limited adjustment signal is sent to the corresponding execution module.

[0050] The preset adjustment step size is determined through parameter calibration during the equipment debugging phase, including the laser crystal temperature adjustment step size, piezoelectric adjustment step size, and pump current adjustment step size. Specifically, closed-loop adjustment tests are performed on the two control channels according to different parameter changes. The response time required for the laser output frequency to recover from the applied disturbance state to within the frequency stability threshold under each parameter value is recorded, and the response times corresponding to two adjacent sets of parameter values ​​are compared. The parameter change is gradually reduced until the response time difference corresponding to two adjacent sets of parameter values ​​does not exceed one preset sampling period. The corresponding temperature adjustment amount is determined as the laser crystal temperature adjustment step size, the corresponding piezoelectric adjustment amount is determined as the piezoelectric adjustment step size, and the corresponding pump current adjustment amount is determined as the pump current adjustment step size.

[0051] After execution, the laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current are collected again according to the preset sampling period. The new frequency deviation is calculated based on the new laser output frequency and the target frequency. When the absolute value of the new frequency deviation is less than the frequency stabilization threshold, it is determined that the basic frequency stabilization adjustment has restored the laser to the frequency stabilization state, and it returns to the frequency stabilization maintenance state. When the absolute value of the new frequency deviation is still greater than or equal to the frequency stabilization threshold, and the absolute value of the frequency deviation has not increased continuously within the preset number of sampling periods, and all the above operating parameters are within the corresponding allowable range, the control channel identification conditions are met again, and the channel probe is entered. Otherwise, it is determined that the current basic frequency stabilization adjustment has not brought the laser into an identifiable state, a prompt message is generated, and the basic frequency stabilization adjustment is maintained.

[0052] Figure 4 This is a schematic diagram of parameter out-of-limit identification in an embodiment of the present invention. The pump current is used as an example. When the pump current exceeds the upper limit of the preset allowable range during the change process, it is identified that the current pump current is in an out-of-limit state. Then, the control process is adjusted according to the boundary constraints of the operating parameters so that the pump current gradually recovers to the allowable range. At the same time, the frequency deviation gradually decreases and recovers to a stable range. This reflects the process of monitoring the boundary of operating parameters such as laser crystal temperature, frequency doubling temperature, and pump current during the control process, and performing amplitude limiting or recovery adjustment when the parameters are close to or exceed the safety boundary.

[0053] When the control channel identification conditions are met, the current pump current adjustment signal and piezoelectric adjustment signal are kept unchanged. The current laser crystal temperature adjustment signal is used as the pre-test control state of the laser crystal temperature control channel. The temperature test direction is determined according to the sign of the current frequency deviation. When the frequency deviation is positive, the test is carried out according to the pre-calibrated temperature adjustment direction that reduces the laser output frequency. When the frequency deviation is negative, the test is carried out according to the pre-calibrated temperature adjustment direction that increases the laser output frequency.

[0054] After determining the direction of the temperature test, the laser crystal temperature adjustment signal at the start of the test is used as a reference. The temperature adjustment signal is adjusted according to the test direction using a preset minimum sensing adjustment amount, while keeping the pump current adjustment signal unchanged. The minimum sensing adjustment amount is determined based on experimental calibration during the equipment commissioning phase; it is the minimum adjustment amount that can produce a detectable change in the laser crystal temperature without causing the laser operating parameters to exceed the allowable range. After adjustment, a preset test cycle is maintained. During the test, the laser output frequency and laser crystal temperature are collected according to the sampling cycle, and the laser output frequency and laser crystal temperature at the start and end of the test are recorded respectively to evaluate the actual response of the laser crystal temperature control channel to the laser output frequency.

[0055] The preset minimum sensing adjustment amount and preset trial period were determined through channel trial experiments during the equipment debugging phase. Specifically, based on the minimum detection resolution of the corresponding detection modules for laser output frequency detection, laser crystal temperature detection, and pump current detection, the minimum frequency identification amount, minimum laser crystal temperature identification amount, minimum piezoelectric identification amount, and minimum pump current identification amount were determined respectively. While keeping other control quantities constant and ensuring that the laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current are all within their respective allowable ranges, progressively increasing adjustment amounts were applied to the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel, respectively. Laser data was then collected according to the preset sampling period. The output frequency and the change in the corresponding controlled object; when the change in the corresponding controlled object reaches the corresponding minimum identification value after the adjustment is applied, and the absolute value of the laser output frequency deviation is less than the absolute value of the frequency deviation before the test, the adjustment that first meets the above conditions is determined as the preset minimum sensing adjustment amount of the corresponding control channel; after applying the preset minimum sensing adjustment amount, the laser output frequency is continuously sampled. When the frequency deviation corresponding to three consecutive sampling cycles does not exceed the preset frequency stability threshold, the time taken from applying the preset minimum sensing adjustment amount to meeting the above stability condition is rounded up to an integer multiple of the preset sampling cycle, which is taken as the preset test cycle of the corresponding control channel, and the above parameters are stored in the database.

[0056] The preset temperature recovery threshold is determined based on the minimum laser crystal temperature identification value determined during the equipment commissioning phase. The minimum laser crystal temperature identification value is used as the preset temperature recovery threshold and stored in the database. The minimum laser crystal temperature identification value is the smallest temperature change that the laser crystal can reliably distinguish, used to characterize the identifiable change in laser crystal temperature relative to the temperature before the test. After the temperature test ends and the temperature adjustment signal is restored to the control state before the test, if the absolute difference between the current laser crystal temperature and the laser crystal temperature before the start of the temperature test is not greater than the minimum laser crystal temperature identification value, it is determined that the laser crystal temperature has recovered to the temperature state before the test.

[0057] The laser output frequency before the start of the laser crystal temperature test is taken as the pre-test frequency, and the laser output frequency at the end of the test cycle is taken as the post-test frequency. The target frequency is subtracted from both the pre-test and post-test frequencies, and the absolute values ​​are taken to obtain the pre-test frequency deviation and the post-test frequency deviation. The laser crystal temperature before the test and the laser output frequency before the test are subtracted from the post-test laser crystal temperature and the pre-test laser output frequency, respectively, to obtain the absolute values ​​of the laser crystal temperature change and the laser output frequency change before and after the test. The absolute value of the laser crystal temperature change is compared with the minimum detection resolution of the corresponding detection module, and the absolute value of the laser output frequency change is compared with the pre-defined... The minimum frequency resolution obtained through experimental calibration during the equipment debugging phase is compared. When the absolute value of the frequency deviation after the test is less than the absolute value of the frequency deviation before the test, and the absolute value of the laser crystal temperature change reaches the corresponding minimum resolution and the absolute value of the laser output frequency change reaches three times the corresponding minimum resolution, it indicates that the applied temperature test can produce a detectable frequency response under the current operating state, and it can be determined that the direction of the response is consistent with the frequency stabilization requirement. Therefore, the laser crystal temperature control channel test is determined to be effective. Otherwise, it is considered that the current test has not obtained a reliable control response, the laser crystal temperature adjustment signal is restored to the control state before the test, and the pump current control channel is tested.

[0058] It should be noted that the absolute value of the laser output frequency change reaching three times the corresponding minimum resolution is used to increase the noise immunity margin based on the minimum frequency resolution. Its value is calibrated based on the frequency detection fluctuation range, natural frequency drift amplitude, and effective trial response during historical operation. In this embodiment, after verification by multiple sets of historical trial data, the noise immunity coefficient is set to 3 to require that the absolute value of the laser output frequency change generated by the trial reaches at least three times the minimum frequency resolution, thereby reducing the probability of misjudging natural frequency fluctuations as control channel responses.

[0059] After identifying the laser crystal temperature control channel, the laser crystal temperature adjustment signal is restored to the control state before the temperature test, and the pump current adjustment signal is kept unchanged to eliminate the continuous impact of the temperature test on the current operating state of the solid-state laser. Subsequently, the laser crystal temperature and laser output frequency are continuously collected according to the preset sampling period. The laser crystal temperature before the start of the temperature test is used as the recovery benchmark. The temperature difference between the current laser crystal temperature and the recovery benchmark is calculated, and the change in laser output frequency at adjacent sampling times is calculated. When the absolute value of the temperature difference is not greater than the preset temperature recovery threshold, and the absolute value of the change in laser output frequency corresponding to the consecutive preset number of sampling periods is not greater than the preset frequency change threshold, it is determined that the dynamic response generated by the temperature test has subsided.

[0060] The frequency change threshold is determined through a trial experiment of the laser crystal temperature control channel during the equipment debugging phase. Specifically, a random trial adjustment is applied to the laser crystal temperature control channel. After the trial is completed and the control state before the trial is restored, the laser output frequency is continuously collected within a preset number of sampling periods. The absolute value of the laser output frequency change at adjacent sampling times is calculated, and the average value and standard deviation of the absolute value of the frequency change are calculated. The sum of the average value and standard deviation is used as the preset frequency change threshold and stored in the database.

[0061] Subsequently, the direction of the pump current adjustment is determined based on the frequency deviation between the current laser output frequency and the target frequency. While keeping the laser crystal temperature adjustment signal constant, a minimum sensing adjustment amount, pre-determined through experimental calibration during the equipment debugging phase, is applied to the pump current adjustment signal, causing the pump current to change along the determined direction based on the current control value. From the application of the minimum sensing adjustment amount, the laser output frequency, pump current, laser crystal temperature, and laser output power are continuously collected according to the sampling period within the preset pump test cycle. The corresponding sampled value before the application of the pump current adjustment amount is used as the pre-test baseline value, and the corresponding sampled value at the end of the test cycle is used as the post-test value. This is used to compare the impact of the pump current test on the laser output frequency and simultaneously determine whether each operating parameter remains within the corresponding allowable range during the test.

[0062] After the pump current test is completed, the laser output frequency and pump current before and after the test are acquired respectively. The changes in laser output frequency and pump current before the test are obtained by subtracting the laser output frequency and pump current before the test from the laser output frequency and pump current after the test. The absolute value of the frequency deviation after the test is obtained by subtracting the target frequency from the laser output frequency after the test. If the absolute value of the frequency deviation after the test is less than the absolute value of the frequency deviation before the test, it indicates that the pump current adjustment has changed the laser output frequency towards the target frequency. Then, it is determined whether the change in pump current has reached the pre-adjusted value through the equipment. During the trial phase, the minimum pump current identification value determined by the experimental calibration, and whether the absolute value of the laser output frequency change reaches the pre-calibrated minimum frequency identification value are checked to ensure that the response generated by the test can be reliably detected. At the same time, the laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current collected during the test are compared with the corresponding allowable ranges. If all the above conditions are met, the pump current control channel test is deemed valid; otherwise, the test is deemed invalid, and the pump current adjustment signal is restored to the control state before the test, the channel identification is exited and basic frequency stabilization adjustment is performed.

[0063] After testing the laser crystal temperature control channel and pump current control channel, the piezoelectric control channel was tested. First, the laser output frequency and piezoelectric driving voltage were recorded before the test began. Under the condition that the preset piezoelectric driving voltage limit was not exceeded, a step adjustment in a preset direction was applied to the piezoelectric driving voltage according to a preset minimum sensing adjustment amount, and this adjustment amount was maintained for a preset piezoelectric test cycle. Since the response speed of the piezoelectric control channel is relatively fast, the piezoelectric test cycle was calibrated based on the step response time of the piezoelectric control channel and was shorter than the test cycle corresponding to the laser crystal temperature control channel. After the piezoelectric test cycle ended, the laser output frequency and piezoelectric driving voltage after the test were obtained. When the absolute value of the frequency deviation after the test decreased compared to before the test, simultaneously… When the piezoelectric drive voltage and other operating parameters are all within the corresponding allowable range, the piezoelectric control channel test is deemed valid. The laser output frequency at the end of the test is subtracted from the laser output frequency at the beginning of the test to obtain the change in laser output frequency. The piezoelectric drive voltage at the end of the test is subtracted from the piezoelectric drive voltage at the beginning of the test to obtain the change in piezoelectric drive voltage. The change in laser output frequency is divided by the change in piezoelectric drive voltage to obtain the unit piezoelectric control response. The unit piezoelectric control response is used to characterize the change in laser output frequency caused by the unit piezoelectric drive voltage change, and the unit is Hz / V. The obtained unit piezoelectric control response is used as the identification result of the current piezoelectric control channel. Otherwise, the piezoelectric control channel test is deemed invalid, and the piezoelectric drive voltage is restored to that before the test.

[0064] If the temperature test is effective, the laser output frequency and laser crystal temperature are obtained at the beginning and end of the temperature test, respectively. The laser output frequency at the end of the test is subtracted from the laser output frequency at the beginning of the test to obtain the change in laser output frequency. The laser crystal temperature at the end of the test is subtracted from the laser crystal temperature at the beginning of the test to obtain the change in laser crystal temperature. The change in laser output frequency is divided by the change in laser crystal temperature to obtain the unit temperature control response, which is used to characterize the degree of change in laser output frequency caused by each unit temperature change of the laser crystal.

[0065] When the pump current test is effective, the laser output frequency and pump current at the start and end of the test are recorded respectively. The change in laser output frequency is obtained by subtracting the laser output frequency at the start of the test from the laser output frequency at the end of the test. The change in pump current is obtained by subtracting the pump current at the start of the test from the pump current at the end of the test. The change in laser output frequency is divided by the change in pump current to obtain the unit pump current control response. The unit pump current control response is used to characterize the degree of change in laser output frequency caused by each unit change in pump current under the current operating state. This response is used as the basis for subsequent calculation of the frequency compensation capability of the pump current control channel and the pump current adjustment amount. After the response calculation is completed, the pump current adjustment signal is restored to the control state before the start of the pump current test to eliminate the influence of the test adjustment on the subsequent coordinated frequency stabilization control.

[0066] During the control channel trial, the laser output frequency is continuously monitored according to the preset sampling period. When the absolute value of the frequency deviation increases continuously within a preset number of sampling periods, the current control channel trial is immediately stopped, the current control parameters are restored to the state before the trial started, the control channel identification is exited, and the basic frequency stabilization adjustment is initiated.

[0067] The current frequency compensation direction is determined based on the sign of the frequency deviation. When the frequency deviation is positive, i.e., the current laser output frequency is higher than the preset target frequency, the current frequency compensation direction is determined to decrease the laser output frequency. When the frequency deviation is negative, i.e., the current laser output frequency is lower than the preset target frequency, the current frequency compensation direction is determined to increase the laser output frequency. Subsequently, the adjustment direction of each control channel is determined according to the sign of the unit control response quantity corresponding to the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel. This causes each control channel to produce a frequency change opposite to the current frequency deviation according to its corresponding frequency response direction. When the unit control response quantity is positive, it means that the corresponding control parameter increases, causing the laser output frequency to rise; when it is negative, it means that the corresponding control parameter increases, causing the laser output frequency to fall. Thus, the specific adjustment directions of the laser crystal temperature, piezoelectric drive voltage, and pump current are determined based on the current frequency compensation direction.

[0068] The maximum adjustable temperature is determined based on the distance between the current laser crystal temperature and the boundary of the laser crystal temperature allowable range. Specifically, when the current laser crystal temperature is adjusted in the direction of heating, the maximum adjustable temperature is obtained by subtracting the current laser crystal temperature from the upper limit of the laser crystal temperature allowable. When the current laser crystal temperature is adjusted in the direction of cooling, the maximum adjustable temperature is obtained by subtracting the lower limit of the laser crystal temperature allowable. This ensures that subsequent temperature adjustments do not exceed the laser crystal temperature allowable range in the current adjustment direction.

[0069] The maximum adjustable piezoelectric amount is determined based on the distance between the current piezoelectric driving voltage and the boundary of the allowable range of the piezoelectric driving voltage. When the adjustment direction of the current piezoelectric driving voltage is increasing, the current piezoelectric driving voltage is subtracted from the upper limit of the allowable piezoelectric driving voltage to obtain the maximum adjustable piezoelectric amount. When the adjustment direction of the current piezoelectric driving voltage is decreasing, the lower limit of the allowable piezoelectric driving voltage is subtracted from the current piezoelectric driving voltage to obtain the maximum adjustable piezoelectric amount.

[0070] The maximum adjustable current of the pump current control channel is determined based on the distance between the current pump current and the boundary of the allowable pump current range. When the adjustment direction of the current pump current is increasing, the maximum adjustable current is obtained by subtracting the current pump current from the upper limit of the allowable pump current. When the adjustment direction of the current pump current is decreasing, the maximum adjustable current is obtained by subtracting the lower limit of the allowable pump current from the current pump current. Figure 5 This is a diagram illustrating the dual-channel compensation capability allocation in this invention. The left diagram (blue) shows the relationship between the maximum frequency compensation capability and the total frequency compensation requirement of the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel. Specifically, the blue portion represents the maximum frequency compensation capability of the pump current control channel, the green portion represents the maximum frequency compensation capability of the laser crystal temperature control channel, the red portion represents the maximum frequency compensation capability of the piezoelectric control channel, and the orange diamond-shaped dots represent the total frequency compensation requirement in kHz. To avoid mixing of the blue portions in the diagram, a white background is set under the color corresponding to the pump current in the diagram. The right diagram shows the allocation of the current total frequency compensation requirement to the two control channels. The blue portion represents the pump current frequency compensation, the green portion represents the laser crystal frequency compensation, and the red portion represents the piezoelectric frequency compensation. This allows the three control channels to jointly complete frequency deviation compensation, reflecting the idea of ​​avoiding over-adjustment of a single control channel during multi-parameter collaborative feedback and fully utilizing multiple control variables for frequency stability control.

[0071] The maximum frequency compensation capability of the laser crystal temperature control channel is determined by multiplying the absolute value of the unit temperature control response by the maximum adjustable temperature; the maximum frequency compensation capability of the piezoelectric control channel is determined by multiplying the absolute value of the unit piezoelectric control response by the maximum adjustable piezoelectric quantity; and the maximum frequency compensation capability of the pump current control channel is determined by multiplying the absolute value of the unit pump current control response by the maximum adjustable current.

[0072] The step response times of the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel are obtained separately. The corresponding response speed factor is determined based on the step response time of each control channel. The relative magnitude of the response speed factor of each control channel is set to the reciprocal of the corresponding step response time. The shorter the step response time, the larger the corresponding response speed factor. The comprehensive compensation weight of each control channel is determined by multiplying the maximum frequency compensation capability of each control channel with the corresponding response speed factor. The comprehensive compensation weight of each control channel is divided by the sum of the comprehensive compensation weights of the three control channels to obtain the corresponding frequency compensation allocation ratio.

[0073] When only one control channel has a maximum frequency compensation capability greater than zero, the frequency compensation allocation ratio of that control channel is set to 1, and the frequency compensation allocation ratio of the remaining control channels is set to 0. When two control channels have a maximum frequency compensation capability greater than zero and the other control channel has a maximum frequency compensation capability not greater than zero, the frequency compensation allocation ratio between the two control channels with effective compensation capability is determined based on the product of the corresponding maximum frequency compensation capability and the response speed factor, and the allocation ratio of the ineffective control channel is set to 0. When the maximum frequency compensation capability of all three control channels is greater than zero, the corresponding frequency compensation allocation ratio is determined based on the comprehensive compensation weight of the three control channels.

[0074] When the maximum frequency compensation capability of the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel is not greater than zero, it indicates that none of the three control channels can provide effective frequency compensation capability under the current operating state. Therefore, this coordinated control is abandoned, and the process returns to the basic frequency stabilization adjustment.

[0075] The total frequency compensation requirement and corresponding compensation direction are determined based on the current frequency deviation. Specifically, the absolute value of the current frequency deviation is taken as the frequency deviation to be compensated, and the maximum frequency compensation capabilities of the laser crystal temperature control channel, the piezoelectric control channel, and the pump current control channel are added together to obtain the total frequency compensation capability of the three control channels. The frequency deviation to be compensated is compared with the total frequency compensation capability. When the frequency deviation to be compensated is greater than the total frequency compensation capability, it is determined that the current frequency deviation exceeds the range of the three-channel collaborative compensation capability, and an insufficient compensation capability warning is generated. When the frequency deviation to be compensated is less than or equal to the total frequency compensation capability, normal collaborative frequency stabilization adjustment continues, and the frequency deviation to be compensated is recorded as the total frequency compensation requirement. The corresponding frequency compensation direction is determined based on the sign of the current frequency deviation relative to the target frequency. When the frequency deviation is greater than zero, it is determined that the current laser output frequency is higher than the target frequency, and the frequency compensation direction is determined to be to reduce the laser output frequency. When the frequency deviation is less than zero, it is determined that the current laser output frequency is lower than the target frequency, and the frequency compensation direction is determined to be to increase the laser output frequency. When the frequency deviation is equal to zero, no frequency compensation is performed.

[0076] The total frequency compensation requirement is allocated according to the frequency compensation allocation ratio of the two control channels. Specifically, the total frequency compensation requirement is multiplied by the frequency compensation allocation ratio of the laser crystal temperature control channel and the frequency compensation allocation ratio of the pump current control channel to obtain the frequency compensation amount of the laser crystal temperature control channel and the frequency compensation amount of the pump current control channel, respectively. The sum of the two frequency compensation amounts equals the total frequency compensation requirement.

[0077] When determining the frequency compensation amount of the pump current control channel, the relative intensity noise of the laser output is simultaneously acquired, and the current relative intensity noise is compared with the preset relative intensity noise allowable range. When the relative intensity noise exceeds the preset noise allowable range calibrated offline by the technician after executing the current pump current adjustment, the compensation amount of the pump current control channel is reduced, and the reduced frequency compensation requirement is redistributed to the laser crystal temperature control channel and piezoelectric control channel that meet the adjustment conditions. When other control channels cannot handle the remaining compensation requirement, the pump current adjustment amount is kept from increasing and a prompt message is generated.

[0078] Figure 6The actual adjustment conversion diagram in this embodiment of the invention includes: after completing the frequency compensation allocation, the frequency compensation amount undertaken by each control channel is further converted into the actual execution parameter adjustment amount. The vertical axis of the left figure represents the laser crystal temperature adjustment amount in °C, and the vertical axis of the right figure represents the pump current adjustment amount in A. Each point is a control command formed by an independent collaborative decision, and no continuous interpolation is made between decision moments. The figure shows the actual laser crystal temperature adjustment amount, piezoelectric adjustment amount, and pump current adjustment amount, that is, the actual execution command is generated.

[0079] Based on the frequency compensation and unit control response corresponding to the two control channels, the frequency compensation is converted into the adjustment amount of the actual control parameters. Specifically, the frequency compensation of the laser crystal temperature control channel is divided by the absolute value of the unit temperature control response to obtain the laser crystal temperature adjustment amount, and the frequency compensation of the pump current control channel is divided by the absolute value of the unit pump current control response to obtain the pump current adjustment amount, thereby determining the actual adjustment amplitude that needs to be applied to the two control channels respectively.

[0080] The laser crystal temperature adjustment is superimposed on the current laser crystal temperature adjustment signal, and the pump current adjustment is superimposed on the current pump current adjustment signal. Based on the corresponding allowable ranges of the laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current, the adjusted control signals are limited to ensure that the operating parameters do not exceed their respective allowable ranges after adjustment. Subsequently, the limited laser crystal temperature adjustment signal is sent to the temperature control execution module, and the limited pump current adjustment signal is sent to the laser driver module to perform coordinated frequency stabilization. After adjustment, the laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current are re-acquired according to a preset sampling period. The frequency deviation is recalculated based on the re-acquired laser output frequency and the target frequency to enter the next round of frequency stabilization control.

[0081] like Figure 7 This diagram illustrates a framework of a solid-state laser frequency stabilization control system based on multi-parameter collaborative feedback, as described in an embodiment of the present invention, including: The frequency stabilization state determination module is used to collect multi-parameter operating data during the operation of the solid-state laser, including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current, and determine the current frequency deviation based on the preset target frequency and frequency stabilization threshold.

[0082] The control channel identification module is used to determine whether to perform control channel identification based on whether the frequency deviation reaches the preset frequency stability threshold and whether the current operating parameters are within the corresponding allowable range. If the identification conditions are not met, the preset basic frequency stabilization adjustment is executed. If the identification conditions are met, the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel are tested respectively, and the corresponding control response is determined based on the laser output frequency, laser crystal temperature, piezoelectric drive voltage, and pump current before and after the test.

[0083] The frequency compensation capability determination module is used to determine the frequency compensation capability of the three control channels based on the current laser crystal temperature, the distance between the piezoelectric driving voltage and the pump current and the corresponding allowable range, as well as the control response quantity, and to determine the frequency compensation allocation ratio.

[0084] The collaborative frequency stabilization control module is used to determine the total frequency compensation requirement based on the frequency deviation and the frequency compensation capability of the three control channels, and to determine the laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment according to the frequency compensation allocation ratio, so as to coordinately adjust the solid-state laser.

[0085] In Embodiment 2 of the present invention, while keeping other steps unchanged from Embodiment 1, the frequency compensation allocation ratio can be determined based on the relative adjustment margin and maximum frequency compensation capability of the two control channels, as detailed below: After identifying the laser crystal temperature control channel, piezoelectric control channel, and pump current control channel, and obtaining their corresponding maximum frequency compensation capabilities, the allowable adjustment boundaries for each of the two control channels are determined based on the current frequency compensation direction. The piezoelectric control channel is responsible for its corresponding frequency compensation and does not participate in the compensation allocation between the laser crystal temperature control channel and the pump current control channel. For example, when the laser crystal temperature increases in the frequency compensation direction, the upper boundary of the allowable laser crystal temperature range is used as the corresponding adjustment boundary; when the laser crystal temperature decreases in the frequency compensation direction, the lower boundary of the allowable laser crystal temperature range is used as the corresponding adjustment boundary. Similarly, when the pump current increases in the frequency compensation direction, the upper boundary of the allowable pump current range is used as the adjustment boundary. The boundary is used as the corresponding adjustment boundary. When the pump current decreases in the frequency compensation direction, the lower boundary of the allowable range of the pump current is used as the corresponding adjustment boundary. Then, the distance between the current laser crystal temperature and the corresponding adjustment boundary and the distance between the current pump current and the corresponding adjustment boundary are calculated respectively. These distances are then divided by the total span of the allowable range of the laser crystal temperature and the allowable range of the pump current to obtain the relative adjustment margin of the laser crystal temperature and the relative adjustment margin of the pump current. The two different physical quantities of temperature and pump current are converted into a unified dimensionless index to represent the safe adjustment space that each of the two control channels can still use in the current frequency compensation direction. This avoids the problem of inconsistent physical dimensions caused by directly comparing the changes in temperature and current.

[0086] The comprehensive compensation capacity of the laser crystal temperature control channel is obtained by multiplying its relative adjustment margin by its maximum frequency compensation capability, and the comprehensive compensation capacity of the pump current control channel is obtained by multiplying its relative adjustment margin by its maximum frequency compensation capability. The maximum frequency compensation capability is used to characterize the maximum frequency compensation that the corresponding control channel can provide under the current operating state, and the relative adjustment margin is used to characterize the safe adjustment space that the corresponding control channel can still use. By multiplying the two, the comprehensive compensation capacity reflects both the frequency compensation capability and the remaining safe adjustment space of the control channel.

[0087] When the sum of the comprehensive compensation capabilities of the two control channels is greater than zero, the comprehensive compensation capability of the laser crystal temperature control channel is divided by the sum of the comprehensive compensation capabilities of the two control channels to obtain the frequency compensation allocation ratio of the laser crystal temperature control channel. The comprehensive compensation capability of the pump current control channel is divided by the sum of the comprehensive compensation capabilities of the two control channels to obtain the frequency compensation allocation ratio of the pump current control channel. The sum of the two frequency compensation allocation ratios is 1, so that the control channel with a larger remaining safety adjustment margin and a stronger maximum frequency compensation capability undertakes a relatively larger frequency compensation ratio.

[0088] When the sum of the comprehensive compensation capabilities of the two control channels is not greater than zero, it indicates that neither control channel can provide effective frequency compensation capability under the current frequency compensation direction. The frequency compensation allocation ratio is not calculated, and the current coordinated frequency stabilization adjustment is abandoned. The basic frequency stabilization adjustment is then performed. When only the comprehensive compensation capability of the laser crystal temperature control channel is greater than zero, the frequency compensation allocation ratio of the laser crystal temperature control channel is set to 1, and the frequency compensation allocation ratio of the pump current control channel is set to 0. When only the comprehensive compensation capability of the pump current control channel is greater than zero, the frequency compensation allocation ratio of the pump current control channel is set to 1, and the frequency compensation allocation ratio of the laser crystal temperature control channel is set to 0.

Claims

1. A method for frequency stabilization control of a solid-state laser based on multi-parameter collaborative feedback, characterized in that, include: Collect multi-parameter operating data during the operation of the solid-state laser, including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric driving voltage and pump current, and determine the current frequency deviation based on the preset target frequency and frequency stability threshold; Based on whether the frequency deviation reaches the preset frequency stability threshold and whether the current operating parameters are within the corresponding allowable range, it is determined whether to perform control channel identification. If the identification conditions are not met, the preset basic frequency stabilization adjustment is executed. If the identification conditions are met, the laser crystal temperature control channel, piezoelectric control channel and pump current control channel are tested respectively, and the corresponding control response quantities are determined based on the laser output frequency, laser crystal temperature, piezoelectric driving voltage and pump current before and after the test. Based on the current laser crystal temperature, the distance between the piezoelectric driving voltage and the pump current and the corresponding allowable range, as well as the control response, the frequency compensation capability of the three control channels is determined, and the frequency compensation allocation ratio is determined. The total frequency compensation requirement is determined based on the frequency deviation and the frequency compensation capability of the three control channels. The laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment are determined according to the frequency compensation allocation ratio to coordinate the adjustment of the solid-state laser.

2. The method for frequency stabilization control of a solid-state laser based on multi-parameter collaborative feedback according to claim 1, characterized in that, The specific analysis method for collecting multi-parameter operating data during the operation of the solid-state laser is as follows: During the operation of the solid-state laser, multi-parameter operating data are collected in real time according to a preset sampling period, including: laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric driving voltage and pump current. Among them, the laser crystal temperature is the direct control object of the laser crystal temperature control channel, and the frequency doubling crystal temperature is used as the temperature state and safety constraint parameter during the operation of the laser. Simultaneously, the target frequency, frequency stability threshold, allowable temperature range of the laser crystal, allowable temperature range of the frequency doubling crystal, allowable range of laser output power, allowable range of piezoelectric drive voltage, and allowable range of pump current corresponding to the solid-state laser are preset.

3. The method for frequency stabilization control of a solid-state laser based on multi-parameter collaborative feedback according to claim 2, characterized in that, The method for determining the current frequency deviation based on the preset target frequency and frequency stability threshold is as follows: Calculate the frequency deviation based on the laser output frequency and the target frequency at the current sampling time; When the absolute value of the frequency deviation is less than the preset frequency stability threshold, it is determined that the current frequency stabilization state is maintained, and the current temperature regulation signal, piezoelectric regulation signal and pump current regulation signal are maintained. When the absolute value of the frequency deviation is greater than or equal to the frequency stability threshold, it is determined whether the absolute value of the frequency deviation increases continuously within a preset number of sampling periods, and whether the laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current are all within the corresponding allowable range. When the absolute value of the frequency deviation at the next sampling moment within a consecutive preset number of sampling periods is greater than the absolute value of the frequency deviation at the previous sampling moment, it is determined that the frequency deviation is continuously increasing; otherwise, it is determined that the frequency deviation is not continuously increasing. When it is determined that the frequency deviation is not continuously increasing and all operating parameters are within the corresponding allowable range, it is determined that the control channel identification condition is met. When the absolute value of the frequency deviation is continuously increasing, the basic frequency stabilization adjustment is executed first. When the continuously increasing state is detected to reach the preset maximum basic frequency stabilization duration, the basic frequency stabilization adjustment is stopped and the control channel identification is forcibly entered. An alarm message is generated when forced identification fails to obtain an effective control response.

4. The frequency stabilization control method for solid-state lasers based on multi-parameter collaborative feedback according to claim 3, characterized in that, The specific analysis method for performing basic frequency stabilization adjustment is as follows: The direction of fundamental frequency compensation is determined based on the sign of the frequency deviation, and the amount of fundamental frequency compensation is calculated using preset proportional and integral coefficients. Based on the pre-calibrated basic temperature compensation allocation ratio, basic piezoelectric compensation allocation ratio, and basic pump current compensation allocation ratio, the basic frequency compensation amount is allocated to the temperature frequency compensation amount corresponding to the laser crystal temperature control channel, the piezoelectric frequency compensation amount corresponding to the piezoelectric control channel, and the current frequency compensation amount corresponding to the pump current control channel, respectively. The unit control response value obtained from the most recent control channel identification is obtained, and the temperature frequency compensation value, piezoelectric frequency compensation value and current frequency compensation value are converted into laser crystal temperature adjustment value, piezoelectric adjustment value and pump current adjustment value respectively based on the unit control response value. When no control channel identification result is available, the pre-calibrated frequency response coefficient of the corresponding control channel is invoked to convert each frequency compensation quantity into the corresponding control adjustment quantity. Based on the fundamental frequency compensation direction and the sign of the frequency response coefficient of the corresponding control channel, the adjustment directions of the laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment are determined respectively. The laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment after the direction is determined are superimposed on the current temperature adjustment signal, the current piezoelectric adjustment signal, and the current pump current adjustment signal respectively. When any operating parameter exceeds the corresponding allowable range, the recovery direction is determined according to the deviation direction of the over-limit operating parameter relative to the upper and lower boundaries of the corresponding allowable range. The temperature regulation signal, piezoelectric regulation signal, and pump current regulation signal are corrected according to the preset adjustment step size to restore the over-limit parameter to the corresponding allowable range. The temperature regulation signal, piezoelectric regulation signal, and pump current regulation signal are limited according to the allowable range corresponding to each operating parameter, and the temperature regulation signal, piezoelectric regulation signal, and pump current regulation signal are executed. After execution, continue to collect new laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage, and pump current. When the absolute value of the new frequency deviation is less than the frequency stabilization threshold, return to the frequency stabilization state. When the absolute value of the new frequency deviation is still greater than or equal to the frequency stabilization threshold and the operating status meets the channel identification conditions again, conduct a trial; otherwise, generate a prompt message.

5. The frequency stabilization control method for a solid-state laser based on multi-parameter collaborative feedback according to claim 1, characterized in that, The specific analysis method for exploring the temperature control channel of the laser crystal is as follows: When the control channel identification conditions are met, the current pump current remains unchanged, the current laser crystal temperature adjustment signal is used as the pre-test control state of the laser crystal temperature control channel, and the temperature test direction is determined according to the current frequency deviation. A preset minimum sensing adjustment amount is applied to the laser crystal temperature control channel, and the laser output frequency and the corresponding laser crystal temperature change are collected within a preset testing period. When the absolute value of the frequency deviation after the laser crystal temperature control channel test is less than the absolute value of the frequency deviation before the test, and the absolute value of the corresponding laser crystal temperature change reaches the corresponding minimum identification value, the laser crystal temperature control channel test is determined to be effective; otherwise, the control state before the test is restored and the pump current control channel and piezoelectric control channel are tested.

6. The frequency stabilization control method for a solid-state laser based on multi-parameter collaborative feedback according to claim 5, characterized in that, The specific analysis method for exploring the pump current control channel and the piezoelectric control channel is as follows: After completing the identification of the laser crystal temperature control channel, restore the laser crystal temperature adjustment signal to the control state before the temperature test, and keep the pump current adjustment signal unchanged; The laser crystal temperature and laser output frequency are continuously collected. When the absolute value of the difference between the current laser crystal temperature and the laser crystal temperature before the temperature test is not greater than the preset temperature recovery threshold, and the absolute value of the change in laser output frequency within a consecutive preset number of sampling periods is not greater than the preset frequency change threshold, it is determined that the dynamic response generated by the temperature test has subsided. Based on the current frequency deviation direction, a preset minimum sensing adjustment amount is applied to the pump current for testing, and during the testing period, the laser output frequency, pump current, laser crystal temperature, frequency doubling crystal temperature, and laser output power are collected. When the absolute value of the frequency deviation after the pump current control channel test is less than the absolute value of the frequency deviation before the test, and the absolute values ​​of the pump current change and the laser output frequency change reach the corresponding minimum identification values, and all operating parameters do not exceed the corresponding allowable range, the pump current test is determined to be effective; otherwise, the current channel identification is exited and basic frequency stabilization adjustment is performed. After the pump current control channel test is completed and the validity criteria are met, a preset minimum sensing adjustment amount is applied to the piezoelectric control channel. After the corresponding piezoelectric test cycle, the laser output frequency is collected. When the absolute value of the frequency deviation after the piezoelectric control channel test is less than the absolute value of the frequency deviation before the test, and the absolute values ​​of the piezoelectric drive voltage change and the absolute values ​​of the laser output frequency change reach the corresponding minimum identification amount, and all operating parameters do not exceed the corresponding allowable range, the piezoelectric control channel test is determined to be valid. Otherwise, the current channel identification is exited and basic frequency stabilization adjustment is performed.

7. The frequency stabilization control method for a solid-state laser based on multi-parameter collaborative feedback according to claim 6, characterized in that, The corresponding control response is determined based on the laser output frequency, laser crystal temperature, piezoelectric driving voltage, and pump current before and after the test. The specific analysis method is as follows: When the temperature test is effective, the change in laser output frequency is determined based on the laser output frequency before and after the temperature test, the change in laser crystal temperature is determined based on the laser crystal temperature before and after the temperature test, and the unit temperature control response is obtained based on the change in laser output frequency and the change in laser crystal temperature, which is used to represent the degree of change in laser output frequency corresponding to the unit change in laser crystal temperature under the current operating state. When the pump current test is effective, the change in laser output frequency is determined based on the laser output frequency before and after the pump current test, the change in pump current is determined based on the pump current before and after the pump current test, and the unit pump current control response is obtained based on the change in laser output frequency and the change in pump current. After the pump current channel identification is completed, the pump current adjustment signal is restored to the control state before the pump current test. When the piezoelectric control channel test is effective, the change in laser output frequency is determined based on the laser output frequency before and after the test, the change in piezoelectric drive voltage is determined based on the piezoelectric drive voltage before and after the test, and the change in laser output frequency is divided by the change in piezoelectric drive voltage to obtain the unit piezoelectric control response. After completing the pump current channel identification, the pump current adjustment signal is restored to the control state before the pump current test.

8. The method for frequency stabilization control of a solid-state laser based on multi-parameter collaborative feedback according to claim 7, characterized in that, The frequency compensation capabilities of the three control channels are determined based on the distance between the current laser crystal temperature, piezoelectric driving voltage, and pump current and their corresponding allowable ranges, as well as the control response, and the frequency compensation allocation ratio is determined. The specific analysis method is as follows: The direction of laser crystal temperature adjustment, piezoelectric drive voltage adjustment, and pump current adjustment is determined based on the sign of the frequency deviation. Based on the distance between the current laser crystal and the upper and lower boundaries of the laser crystal's allowable temperature range, and combined with the current laser crystal temperature adjustment direction, determine the maximum adjustable temperature of the laser crystal temperature control channel. Based on the distance between the current pump current and the allowable range of the pump current, and in conjunction with the currently determined pump current adjustment direction, determine the maximum adjustable current of the pump current control channel. Based on the distance between the current piezoelectric driving voltage and the allowable range of the piezoelectric driving voltage, and in conjunction with the currently determined piezoelectric driving voltage adjustment direction, determine the maximum adjustable voltage of the piezoelectric control channel; The maximum frequency compensation capability that the current laser crystal temperature control channel can provide is obtained by combining the unit temperature control response with the maximum adjustable temperature; the maximum frequency compensation capability that the current pump current control channel can provide is obtained by combining the unit pump current control response with the maximum adjustable current; and the maximum frequency compensation capability that the current piezoelectric control channel can provide is obtained by combining the unit drive voltage control response with the maximum adjustable voltage. The proportion of the maximum frequency compensation capability of the three control channels in the sum of the three channels is used to determine the temperature control allocation ratio of the laser crystal temperature control channel, the piezoelectric control allocation ratio of the piezoelectric control channel, and the pump current control allocation ratio of the pump current control channel, respectively. When only one or two control channels have effective maximum frequency compensation capability, all frequency compensation tasks will be assigned to that control channel. When none of the three control channels have effective maximum frequency compensation capability, abandon this coordinated control and perform basic frequency stabilization adjustment.

9. The frequency stabilization control method for a solid-state laser based on multi-parameter collaborative feedback according to claim 8, characterized in that, The total frequency compensation requirement is determined based on the frequency deviation and the frequency compensation capability of the three control channels. The laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment are then determined according to the frequency compensation allocation ratio to coordinate the adjustment of the solid-state laser. The specific analysis method is as follows: Determine the total frequency compensation requirement and the corresponding compensation direction based on the current frequency deviation; Multiply the total frequency compensation requirement by the obtained temperature control allocation ratio, piezoelectric control allocation ratio, and pump current control allocation ratio respectively to obtain the frequency compensation amount corresponding to temperature control, piezoelectric control, and pump current control. The temperature regulation amount is obtained by dividing the frequency compensation amount corresponding to the temperature control by the absolute value of the unit temperature control response amount, the piezoelectric regulation amount is obtained by dividing the frequency compensation amount corresponding to the piezoelectric control by the absolute value of the unit piezoelectric control response amount, and the pump current regulation amount is obtained by dividing the frequency compensation amount corresponding to the pump current control by the absolute value of the unit pump current control response amount. The temperature adjustment value, piezoelectric adjustment value, and pump current adjustment value are superimposed on the current temperature adjustment signal, piezoelectric adjustment value, and pump current adjustment value, respectively. The three adjustment signals are then limited according to the allowable ranges of laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric driving voltage, and pump current. Finally, the limited temperature adjustment signal is sent to the temperature control execution module, and the limited pump current adjustment signal is sent to the laser driver module to jointly regulate the operating state of the solid-state laser. After completing the coordinated control, the new laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric driving voltage, and pump current are collected according to the sampling period. The frequency deviation is recalculated based on the new laser output frequency and the target frequency.

10. A frequency stabilization control system for a solid-state laser based on multi-parameter collaborative feedback, characterized in that, include: The frequency stabilization state determination module is used to collect multi-parameter operating data during the operation of the solid-state laser, including laser output frequency, laser crystal temperature, frequency doubling crystal temperature, laser output power, piezoelectric drive voltage and pump current, and determine the current frequency deviation based on the preset target frequency and frequency stabilization threshold. The control channel identification module is used to determine whether to perform control channel identification based on whether the frequency deviation reaches the preset frequency stability threshold and whether the current operating parameters are within the corresponding allowable range. If the identification conditions are not met, the preset basic frequency stabilization adjustment is executed. If the identification conditions are met, the laser crystal temperature control channel, piezoelectric control channel and pump current control channel are tested respectively, and the corresponding control response is determined based on the laser output frequency, laser crystal temperature, piezoelectric driving voltage and pump current before and after the test. The frequency compensation capability determination module is used to determine the frequency compensation capability of the three control channels based on the current laser crystal temperature, piezoelectric driving voltage and pump current and the distance between them and the corresponding allowable range, as well as the control response quantity, and to determine the frequency compensation allocation ratio. The collaborative frequency stabilization control module is used to determine the total frequency compensation requirement based on the frequency deviation and the frequency compensation capability of the three control channels, and to determine the laser crystal temperature adjustment, piezoelectric adjustment, and pump current adjustment according to the frequency compensation allocation ratio, so as to coordinately adjust the solid-state laser.

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