Adjustable optical compensation method and device for laser resonant cavity

Abstract

The invention provides an adjustable optical compensation method and device for a laser resonant cavity. The method comprises the following steps: acquiring working condition parameters of operation of a target laser and current thermal state data of a gain crystal; determining first thermal lens focal power under the current working condition based on the working condition parameters in combination with a preset parameter focal power mapping table, and determining second thermal lens focal power under the current working condition based on the current thermal state data in combination with a preset thermal-optical conversion mapping table; performing deviation correction based on the first thermal lens focal power and the second thermal lens focal power to obtain corrected target thermal lens focal power; and determining a target compensation lens based on the target thermal lens focal power and the fixed focal power of the concave end surface of the gain crystal in the resonant cavity in combination with a preset stable margin condition and the compensation lens focal power corresponding to a plurality of preset compensation lenses. The requirement for frequent switching of working condition parameters is met, and the technical effects that the laser output power is stable, the light beam quality is good, and switching is efficient and reliable are achieved.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and in particular to an adjustable optical compensation method and apparatus for laser resonator cavities. Background Technology

[0002] In solid-state laser devices such as xenon lamp side-pumped solid-state lasers, the stability of the resonant cavity directly determines the stability of the laser output power and the beam quality. Because the gain medium generates a bulk heat source effect during pumping, the temperature gradient induces effects such as refractive index gradient and stress birefringence. In engineering, these dominant effects are typically represented as a thermal lens with positive optical power, whose equivalent focal length changes significantly with the pump thermal load. For widely used planar-planar resonant cavities, they lack inherent stability at the geometrical optical level and rely on the positive focusing effect provided by the thermal lens to ensure that the resonant cavity's ABCD matrix satisfies the stability condition, thus forming an oscillating fundamental mode.

[0003] Existing technologies address the characteristic of planar resonators relying on the thermal lensing effect of the gain medium for stable oscillation. A common approach is to fabricate a concave structure on the end face of the gain crystal for optical compensation. This involves providing a fixed negative optical power through the concave surface to counteract the excessive positive optical power of the thermal lensing under high-power / high-frequency conditions, thus ensuring the resonator meets stability requirements and optimizes mode volume utilization. However, the adjustment or replacement of the compensation lens in existing optical compensation methods relies on manual operation, resulting in low switching efficiency and poor repeatability, making it unsuitable for scenarios with frequent changes in operating parameters. Furthermore, the negative optical power of the concave crystal is a fixed value, only adaptable to a single thermal lensing intensity range, failing to cover the wide range of thermal lensing power variations. When the laser switches to low-power / low-frequency conditions, overcompensation can easily lead to insufficient net optical power in the resonator, causing the planar resonator to fall into an unstable region, resulting in output power fluctuations and beam distortion. Conversely, under high-frequency / high-power conditions with strong thermal lensing, insufficient compensation may lead to a decrease in mode volume utilization, failing to meet the high precision requirements of laser output. Summary of the Invention

[0004] This invention provides an adjustable optical compensation method and apparatus for laser resonators, which solves the problem of resonator instability caused by overcompensation under low power / low frequency conditions, optimizes the mode volume utilization under high power / high frequency conditions, and adapts to the need for frequent switching of operating parameters. It achieves the technical effects of stable laser output power, good beam quality and efficient and reliable switching, and meets the high precision requirements of laser output.

[0005] In a first aspect, the present invention provides a tunable optical compensation method for a laser resonator, comprising: Acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; Based on the operating condition parameters and a preset parameter focal length mapping table, the first thermal lens optical focal length under the current operating condition is determined, and based on the current thermal state data and a preset thermo-optical conversion mapping table, the second thermal lens optical focal length under the current operating condition is determined. The target thermal lens optical power is obtained by performing deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses, the target compensation lens is determined. Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

[0006] In a second aspect, the present invention also provides an adjustable optical compensation device for a laser resonator, applied to the adjustable optical compensation method for a laser resonator as described in the first aspect; the adjustable optical compensation device for the laser resonator includes: The data acquisition module is used to acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; The thermal lens optical power determination module is used to determine the first thermal lens optical power under the current operating condition based on the operating condition parameters and a preset parameter optical power mapping table, and to determine the second thermal lens optical power under the current operating condition based on the current thermal state data and a preset thermo-optical conversion mapping table. The deviation correction module is used to perform deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens to obtain the corrected target optical power of the thermal lens. The compensation lens selection module is used to determine the target compensation lens based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lenses corresponding to multiple preset compensation lenses. The lens switching and interlocking control module is used to switch the target compensation lens to the working position in the optical path of the resonant cavity based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, and release the interlocking restriction on the laser's operating state based on the target compensation lens's positioning signal, so that the laser can operate according to the current operating parameters.

[0007] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing computer software programs; and a processor for reading and executing the computer software programs, thereby implementing the adjustable optical compensation method for a laser resonator as described above.

[0008] Fourthly, the present invention also provides a non-transitory computer-readable storage medium storing a computer software program, which, when executed by a processor, implements the tunable optical compensation method for a laser resonator as described above.

[0009] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the adjustable optical compensation method for a laser resonator as described above.

[0010] The adjustable optical compensation method for laser resonators provided in this invention obtains the optical power of a first thermal lens by combining acquired operating parameters with a preset parameter focal length mapping table, and obtains the optical power of a second thermal lens by combining acquired current thermal state data with a preset thermo-optical conversion mapping table. This achieves preliminary quantification of the optical power of the thermal lens from different dimensions, and performs deviation correction on the first and second thermal lens optical powers to obtain a target thermal lens optical power that more closely matches the actual operating conditions. This solves the problem of optical power calculation deviation that may be caused by a single data source. Furthermore, by combining the target thermal lens optical power, the fixed optical power of the concave end face of the gain crystal, and preset stability margin conditions and the optical power of multiple compensation lenses, the method achieves the desired optical power. The focal length is precisely selected to identify the target compensation lens that can ensure the stability of the resonant cavity, avoiding the limitation of fixed concave crystals that are only suitable for a single operating condition. Finally, the target compensation lens is automatically switched to the working position by rotating the mirror wheel assembly. Once in position, the interlocking restriction is released, allowing the laser to operate according to the current operating condition. This replaces manual operation and improves switching efficiency and repeatability. In summary, this method not only solves the problem of resonant cavity instability caused by over-compensation under low power / low frequency conditions, but also optimizes the mode volume utilization rate under high power / high frequency conditions. At the same time, it adapts to the need for frequent switching of operating parameters, achieving the technical effect of stable laser output power, good beam quality, and efficient and reliable switching, thus meeting the high precision requirements of laser output. Attached Figure Description

[0011] Figure 1 This is a schematic flowchart of an adjustable optical compensation method for a laser resonator provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the adjustable optical compensation device for a laser resonator provided in an embodiment of the present invention; Figure 3 An embodiment diagram of the electronic device provided in this invention; Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with the present invention. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0015] See Figure 1 , Figure 1 This is a schematic flowchart of the adjustable optical compensation method for a laser resonator provided by the present invention. In this embodiment, the main body executing the adjustable optical compensation method for a laser resonator is an adjustable optical compensation device. Therefore, the adjustable optical compensation method for a laser resonator includes: Step 10: Obtain the operating parameters of the target laser and the current thermal state data of the gain crystal.

[0016] Optionally, the adjustable optical compensation device connects to the target laser's operation control system to collect real-time operating parameters of the target laser, including repetition frequency, average power, duty cycle, and cooling temperature. The repetition frequency refers to the number of times the laser output pulses are repeated, measured in Hertz; the average power refers to the average energy output by the laser over a certain period, measured in Watts; the duty cycle is the ratio of the pulse working time to the total time of one pulse cycle; and the cooling temperature refers to the temperature of the cooling medium in the laser's cooling system, measured in degrees Celsius. Each parameter is collected multiple times (at least three times) during the acquisition process, and the average value is taken as the final collected data. Simultaneously, the adjustable optical compensation device also collects real-time thermal state data of the gain crystal, including real-time temperature values, using an embedded temperature sensor positioned at the center of the side of the gain crystal. The temperature detection accuracy is controlled within ±0.1 degrees Celsius, and the detection frequency is consistent with the operating parameter acquisition frequency, for example, once per second. The gain crystal is the core component in the laser that realizes energy conversion and optical amplification.

[0017] In one embodiment, assuming the target laser is a xenon lamp side-pumped solid-state laser, the adjustable optical compensation device establishes a data communication connection with the control system of the laser to obtain in real time: repetition frequency of 50 Hz, average power of 100 watts, duty cycle of 0.3, cooling temperature of 25 degrees Celsius, and at the same time, the temperature sensor attached to the center of the side of the gain crystal detects that the current actual temperature of the gain crystal is 42.3 degrees Celsius.

[0018] Step 20: Based on the operating condition parameters and a preset parameter focal length mapping table, determine the optical focal length of the first thermal lens under the current operating condition, and based on the current thermal state data and a preset thermo-optical conversion mapping table, determine the optical focal length of the second thermal lens under the current operating condition.

[0019] Optionally, the adjustable optical compensation device uses the repetition frequency, average power, duty cycle, and cooling temperature from the operating parameters as query indexes to perform a lookup and matching in a preset parameter focal length mapping table to determine the first thermal lens optical power under the current operating condition, as described in steps 201 to 205. The parameter focal length mapping table, established through prior calibration experiments, contains the correspondence between different combinations of repetition frequency, average power, duty cycle, and cooling temperature and their corresponding thermal lens optical powers. The thermal lens optical power refers to the quantitative index of the equivalent lens effect caused by the refractive index distribution and end-face deformation of the gain medium due to pump heating.

[0020] Furthermore, the adjustable optical compensation device performs a matching query in a preset thermo-optical conversion mapping table based on the real-time temperature data of the current thermal state data to obtain the thermal lens optical power corresponding to the real-time temperature data. This obtained thermal lens optical power is then used as the second thermal lens optical power. The thermo-optical conversion mapping table, also established through prior experimental calibration (i.e., experimental data fitting), establishes a correspondence between different actual temperatures of the gain crystal and their corresponding thermal lens optical powers. The thermo-optical conversion mapping table and the parameter focal length mapping table are pre-stored in the adjustable optical compensation device or in the target laser's storage module, and are retrieved by the adjustable optical compensation device when needed. During the determination of the second thermal lens optical power, if the detected actual temperature exceeds the temperature range of the mapping table, the thermal lens optical power corresponding to the temperature closest to that temperature is selected from the mapping table and marked as interpolation supplementary data. In one embodiment, the adjustable optical compensation device, based on the obtained gain crystal temperature of 42.3 degrees Celsius, matches and queries the thermo-optical conversion mapping table to find that the corresponding thermal lens optical power of 42.3 degrees Celsius is 0.78 per meter, and directly obtains this value as the second thermal lens optical power.

[0021] Step 30: Based on the optical power of the first thermal lens and the optical power of the second thermal lens, perform deviation correction to obtain the corrected target optical power of the thermal lens.

[0022] Optionally, the adjustable optical compensation device performs deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Using the optical power of the second thermal lens as the basic reference value, it eliminates the systematic deviation and data error of the optical power of the thermal lens obtained by the two different test methods, thereby obtaining the corrected target optical power of the thermal lens, as specifically in steps 301 to 304.

[0023] Step 40: Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lenses corresponding to multiple preset compensation lenses, determine the target compensation lens.

[0024] Optionally, the adjustable optical compensation device obtains the fixed optical power of the concave end face of the gain crystal in the resonant cavity of the target laser, and retrieves the stored stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses. It combines these with the corrected optical power of the target thermal lens to obtain a target compensation lens adapted to the current operating conditions, as described in steps 401 to 407.

[0025] Step 50: Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

[0026] Optionally, the adjustable optical compensation device drives a rotating mirror wheel assembly located within the resonant cavity to rotate, starting from the target compensation lens (e.g., via a stepper motor). The rotating mirror wheel assembly precisely rotates to the position corresponding to the target compensation lens according to instructions, switching the target compensation lens to its working position in the resonant cavity's optical path. This ensures the target compensation lens is accurately inserted into the optical transmission path of the resonant cavity. The rotating mirror wheel assembly is a rotating structure with multiple positions, each corresponding to a preset compensation lens. The instructions are determined by the relationship between the current position of the preset compensation lens and the position of the target compensation lens. During the switching process, the positioning accuracy of the drive assembly is controlled within ±0.01 mm to ensure the accuracy of the lens insertion position. Furthermore, to prevent abnormal resonant cavity operation, decreased laser output quality, or even equipment damage due to the lens not being in place, the laser's operating status is interlocked and restricted, preventing the laser from operating according to the current operating parameters.

[0027] Furthermore, the adjustable optical compensation device monitors the position of the rotating mirror assembly in real time. When it detects that the target compensation lens has accurately reached the working position, it sends a position signal to the corresponding controller. Upon receiving the position signal, the controller immediately releases the interlock restrictions on the laser's operating status and sends a permission signal to the laser operation control system, enabling the laser to operate normally according to the current operating parameters obtained in step 10, thus completing the entire adjustable optical compensation process. Simultaneously, it should be noted that if the position confirmation module does not detect a position signal within 3 seconds after the switching operation, the controller controls the drive assembly to re-execute the switching operation, with a maximum of 3 retries. If the attempt still fails, an alarm signal is issued and the interlock restrictions are maintained.

[0028] In one embodiment, after the adjustable optical compensation device determines that the target compensation lens is a plano-convex lens, the controller sends a switching command to the stepper motor. The stepper motor drives the rotating mirror wheel assembly to rotate, moving the position of the plano-convex lens to the working position of the resonant cavity optical path. Simultaneously, the encoder and Hall sensor inside the laser detect that the plano-convex lens has accurately reached its position and send a positioning signal to the controller. Upon receiving the positioning signal, the controller releases the interlocking restrictions on the laser. At this point, the laser operates normally according to the operating parameters of a repetition frequency of 50 Hz, an average power of 100 watts, a duty cycle of 0.3, and a cooling temperature of 25 degrees Celsius.

[0029] This invention provides an embodiment of the invention that obtains the first thermal lens optical power by combining acquired operating condition parameters with a preset parameter focal power mapping table, and obtains the second thermal lens optical power by combining acquired current thermal state data with a preset thermo-optical conversion mapping table. This achieves preliminary quantification of the thermal lens optical power from different dimensions, and corrects for deviations between the first and second thermal lens optical powers to obtain a target thermal lens optical power that more closely matches the actual operating conditions. This solves the problem of optical power calculation deviations that may occur due to a single data source. Furthermore, by combining the target thermal lens optical power, the fixed optical power of the concave end face of the gain crystal, and preset stability margin conditions and the optical power of multiple compensation lenses, the invention accurately selects the lenses that can harmonize the optical power of the target thermal lens. The target compensation lens, which meets the stability requirements of the resonant cavity, avoids the limitation of fixed concave crystals that are only suitable for a single working condition. Finally, the target compensation lens is automatically switched to the working position by rotating the mirror wheel assembly. After it is in position, the interlock restriction is released, allowing the laser to operate according to the current working condition. This replaces manual operation and improves switching efficiency and repeatability. In summary, it not only solves the problem of resonant cavity instability caused by over-compensation under low power / low frequency conditions, but also optimizes the mode volume utilization rate under high power / high frequency conditions. At the same time, it adapts to the need for frequent switching of working parameters, achieving the technical effect of stable laser output power, good beam quality, and efficient and reliable switching, thus meeting the high precision requirements of laser output.

[0030] Optionally, the process of steps 201 to 205 includes: Step 201: Based on the repetition frequency, average power, duty cycle, and cooling temperature as a joint index, a search and matching is performed with the parameter focal value mapping table to obtain the first matching result.

[0031] Optionally, the adjustable optical compensation device uses a combination of four operating parameters—repetition frequency, average power, duty cycle, and cooling temperature—as a joint index to search all calibration records one by one in the parameter focal length mapping table. It then compares whether the current joint index is completely consistent with the combination of operating parameters in each calibration record. After the search is completed, a first matching result is generated.

[0032] In one embodiment, the adjustable optical compensation device acquires the following current operating parameters: repetition frequency 50 Hz, average power 100 watts, duty cycle 0.3, and cooling temperature 25 degrees Celsius. Using these four types of parameters as a joint index, a search and matching process is performed in the parameter focal length mapping table. Each combination of operating parameters is compared with the calibrated combinations in the table to check if there is a record that is completely consistent with the four types of parameters. Finally, the first matching result is obtained to determine whether there is a completely consistent calibration record.

[0033] Step 202: If the first matching result is that there is a completely consistent calibration record, then the thermal lens optical power value corresponding to the calibration record is determined as the first thermal lens optical power. If the first matching result is that there is no completely consistent calibration record, then multiple calibrated working points adjacent to the working condition parameters are identified in the parameter optical power mapping table to obtain the interpolation reference point set.

[0034] Optionally, based on the obtained first matching result, if the first matching result indicates the existence of a completely identical calibration record, it means that the current operating condition parameter has a completely corresponding thermal lens power data within the previously calibrated operating condition range. Therefore, the thermal lens power value associated with the calibration record is directly determined as the first thermal lens power. If the first matching result indicates the absence of a completely identical calibration record, it means that the current operating condition parameter is not completely consistent with the combination of operating condition parameters in each calibration record, i.e., the current operating condition parameter is not on the previously calibrated operating condition grid point. Therefore, the adjustable optical compensation device identifies multiple calibrated operating condition parameters adjacent to the current operating condition parameter in the parameter power mapping table. The term "nearby calibrated operating point" refers to a set of nearby calibrated operating points where the difference between the parameter values ​​in each of the four dimensions—repetition frequency, average power, duty cycle, and cooling temperature—and the corresponding parameter values ​​in the current operating condition is within a preset proximity threshold range. This preset proximity threshold range is determined based on the grid density of the calibrated operating points and is used to ensure that the selected nearby operating points accurately reflect the correlation between the operating parameters and the thermal lens power. For example, the proximity threshold for repetition frequency is ±10 Hz, the proximity threshold for average power is ±20 watts, the proximity threshold for duty cycle is ±0.1, and the proximity threshold for cooling temperature is ±3 degrees Celsius. These identified nearby calibrated operating points are collectively used to form an interpolation reference point set.

[0035] In one embodiment, if the first matching result of step 201 is that there is a completely identical calibration record, and the corresponding thermal lens power value is 0.8 per meter, then the adjustable optical compensation device directly determines 0.8 per meter as the first thermal lens power; if the first matching result is that there is no completely identical calibration record, then the adjustable optical compensation device identifies four calibrated operating points adjacent to the current operating parameters (repetition frequency 50 Hz, average power 100 watts, duty cycle 0.3, cooling temperature 25 degrees Celsius) in the parameter power mapping table, namely (40 Hz, 80 watts, 0.2, 22 degrees Celsius), (60 Hz, 80 watts, 0.2, 28 degrees Celsius), (40 Hz, 120 watts, 0.4, 28 degrees Celsius), and (60 Hz, 120 watts, 0.4, 22 degrees Celsius). These four calibrated operating points form an interpolation reference point set.

[0036] Step 203: Based on the repetition frequency, average power, duty cycle, and cooling temperature corresponding to each calibrated operating point in the interpolation reference point set, and their associated stored thermal lens power values, construct multiple sets of corresponding data pairs between four-dimensional operating parameters and one-dimensional thermal lens power.

[0037] Optionally, the adjustable optical compensation device uses complete information of each calibrated operating point in the interpolation reference point set, including four types of four-dimensional operating parameters corresponding to the calibrated operating point: repetition frequency, average power, duty cycle, and cooling temperature, as well as the thermal lens optical power value stored in the parameter optical power mapping table associated with the calibrated operating point. It associates and binds the four-dimensional operating parameters of each calibrated operating point with the corresponding one-dimensional thermal lens optical power value to form a set of corresponding data pairs containing four-dimensional operating parameters and one-dimensional thermal lens optical power. The number of calibrated operating points in the interpolation reference point set corresponds to the number of corresponding data pairs.

[0038] Step 204: Perform multilinear interpolation on the operating parameters in the corresponding data pair to obtain continuous optical power estimates.

[0039] Optionally, the adjustable optical compensation device performs multilinear interpolation on the operating parameters in the constructed sets of corresponding data pairs. Taking the currently acquired operating parameters as the target point, it calculates the weighting coefficients of the target point relative to each calibrated operating point in the interpolation reference set in four dimensions: repetition frequency, average power, duty cycle, and cooling temperature. The magnitude of the weighting coefficient is inversely proportional to the parameter distance from the target point to each calibrated operating point; the closer the parameter distance, the larger the weighting coefficient. Then, the thermal lens power value corresponding to each calibrated operating point is multiplied by its respective weighting coefficient, and all the product results are summed to obtain a continuous (i.e., smooth and without jumps) power estimate.

[0040] Furthermore, when determining the weight coefficients of the target point relative to each calibrated operating point in the interpolation reference point set, the current operating parameters and the four types of parameters of each calibrated operating point in the interpolation reference point set are first mapped to the [0,1] interval for normalization processing to eliminate the calculation influence caused by the difference in the units of different parameters. Then, the absolute difference between the normalized value of the current operating parameters and the normalized value of the corresponding parameters of each calibrated operating point is calculated for the four dimensions of repetition frequency, average power, duty cycle, and cooling temperature. After that, the local weights of each calibrated operating point in the four dimensions are multiplied to obtain the initial weight of the calibrated operating point. Finally, the initial weights of all calibrated operating points are summed, and the initial weight of each calibrated operating point is divided by the sum to obtain the final weight coefficient.

[0041] In one embodiment, the adjustable optical compensation device uses the current operating parameters (50 Hz, 100 watts, 0.3, 25 degrees Celsius) as the target point and performs multilinear interpolation on four corresponding data pairs. First, the weighting coefficients for each calibrated operating point are calculated to be 0.25, 0.25, 0.25, and 0.25, respectively. Then, each weighting coefficient is multiplied by the thermal lens power value in the corresponding data pair and summed, i.e., (0.25×0.6+0.25×0.7+0.25×0.9+0.25×0.8) per meter = 0.75 per meter, which is the estimated power value.

[0042] Step 205: Based on the estimated optical power value and the physical reasonable range of the preset thermal lens optical power, determine the first thermal lens optical power under the current operating conditions.

[0043] Optionally, the adjustable optical compensation device determines the first thermal lens optical power under the current operating condition based on the estimated optical power value combined with the preset physically reasonable range of thermal lens optical power, as in steps 2051 to 2052. The physically reasonable range of thermal lens optical power is determined based on the working principle of the laser, the material characteristics of the gain crystal, and a large amount of calibration experimental data in the early stage. It is used to filter out abnormal optical power values ​​that do not conform to physical laws. For example, the range of this range is from 0.05 per meter to 1.5 per meter.

[0044] This invention uses four types of operating condition parameters as a joint index to retrieve the parameter focal length mapping table, ensuring the accuracy of the query and avoiding matching deviations caused by single parameter retrieval. Based on the matching results, it flexibly selects to directly retrieve values ​​or construct an interpolation reference point set, adapting to different scenarios inside and outside the calibration operating condition. Then, through multilinear interpolation processing, continuous optical focal length estimates are obtained, making full use of the effective information of neighboring calibration operating condition points, realizing reasonable prediction of thermal lens optical focal length at non-calibration operating condition points. Finally, the optical focal length estimates are screened and calibrated by combining a preset physical reasonable range, eliminating abnormal values ​​and ensuring the physical validity of the results.

[0045] Optionally, the process of steps 2051 to 2052 includes: Step 2051: Based on the optical power estimate and the physical reasonable range, a matching judgment is made. If the optical power estimate is within the physical reasonable range, the value is determined as the first thermal lens optical power. If the optical power estimate is not within the physical reasonable range, all thermal lens optical power values ​​corresponding to the interpolation reference point set are matched with the physical reasonable range to obtain all calibrated working points within the physical reasonable range.

[0046] Optionally, the adjustable optical compensation device compares the estimated optical power value with a preset physically reasonable range (e.g., 0.05 per meter to 1.5 per meter) of the thermal lens optical power, determining whether the estimated optical power value falls within this range. If the estimated optical power value is greater than or equal to the lower limit of the physically reasonable range and less than or equal to the upper limit, it indicates that the estimated optical power value conforms to the physical law of thermal lens optical power, and therefore the adjustable optical compensation device directly determines the estimated optical power value as the first thermal lens optical power value. If the estimated optical power value is less than the lower limit of the physically reasonable range or greater than the upper limit, it indicates that the estimated optical power value is abnormal. In this case, the adjustable optical compensation device, based on the obtained interpolation reference point set, traverses all the thermal lens optical power values ​​associated with the calibrated working points in the reference point set, and determines whether each thermal lens optical power value is within the physically reasonable range, thus filtering out all calibrated working points whose thermal lens optical power values ​​are within the physically reasonable range.

[0047] Step 2052: Based on the thermal lens power values ​​corresponding to all calibrated operating points within the physically reasonable range, select the calibrated operating point corresponding to the thermal lens power value that is closest to the estimated power value, and associate the thermal lens power value stored with the calibrated operating point with the first thermal lens power value.

[0048] Optionally, the adjustable optical compensation device extracts the thermal lens power value associated with each calibrated operating point from all the selected calibrated operating points within a physically reasonable range. It then calculates the absolute difference between each thermal lens power value and the estimated power value (i.e., the absolute value of the subtraction of the two values). This difference quantifies the closeness between the two values; the smaller the absolute difference, the closer the two values ​​are. Finally, all calculated absolute differences are compared, and the calibrated operating point with the smallest absolute difference is identified. The thermal lens power value corresponding to this calibrated operating point is the value closest to the estimated power value. This closest thermal lens power value is determined as the first thermal lens power value under the current operating condition, and the replacement due to an abnormal power value estimate is recorded for future maintenance and traceability.

[0049] The embodiments of the present invention effectively solve the problem of possible anomalies in the optical power estimation under non-calibrated working conditions, make up for the numerical deviation caused by simple boundary correction, and further improve the reliability and accuracy of the optical power of the first thermal lens.

[0050] Optionally, the processes of steps 301 to 304 include: Step 301: Calculate the absolute difference between the optical power of the first thermal lens and the optical power of the second thermal lens to obtain the optical power deviation of the thermal lens.

[0051] Optionally, the adjustable optical compensation device calculates the difference between the first thermal lens optical power and the second thermal lens optical power, and then takes the absolute value of the calculation result to obtain the thermal lens optical power deviation. The deviation is used to quantify the degree of difference between the two thermal lens optical powers, and the unit is the same as the thermal lens optical power, which is per meter.

[0052] Step 302: Based on the thermal lens optical power deviation and the preset deviation tolerance threshold, a comparison is made. If the thermal lens optical power deviation is less than or equal to the deviation tolerance threshold, the second thermal lens optical power is determined as the target thermal lens optical power.

[0053] Optionally, the adjustable optical compensation device compares the optical power deviation of the thermal lens with a preset deviation tolerance threshold based on the thermal lens optical power deviation. If the thermal lens optical power deviation is less than or equal to the deviation tolerance threshold, it indicates that the difference in optical power between the two thermal lenses is small, and the optical power of the second thermal lens is sufficient to accurately reflect the actual state of the thermal lens under the current operating conditions. Therefore, the optical power of the second thermal lens is directly determined as the target thermal lens optical power. The deviation tolerance threshold is pre-stored in the adjustable optical compensation device or the laser and is determined based on extensive experimental data and engineering experience. It is used to determine whether the difference between the optical power of the first thermal lens and the optical power of the second thermal lens is within an acceptable range, for example, a value of 0.05 per meter.

[0054] Step 303: If the optical power deviation of the thermal lens is greater than the deviation tolerance threshold, the deviation direction is determined based on the relative magnitude relationship between the optical power of the first thermal lens and the optical power of the second thermal lens; the deviation direction includes positive deviation or negative deviation.

[0055] Optionally, in the comparison and judgment of the optical power deviation of the thermal lens and the deviation tolerance threshold, if the optical power deviation of the thermal lens is greater than the deviation tolerance threshold, it indicates that the difference in optical power between the two thermal lenses exceeds the acceptable range. Then, the relative magnitude relationship between the optical power of the first thermal lens and the optical power of the second thermal lens is further judged to determine the deviation direction. The deviation direction includes positive deviation and negative deviation. A positive deviation means that the value of the optical power of the first thermal lens is greater than the value of the optical power of the second thermal lens, and a negative deviation means that the value of the optical power of the first thermal lens is less than the value of the optical power of the second thermal lens.

[0056] Step 304: Based on the deviation direction, the optical power of the second thermal lens is used as a basic reference value and combined with the optical power deviation of the thermal lens to perform deviation correction, so as to obtain the corrected target optical power of the thermal lens.

[0057] Optionally, the adjustable optical compensation device corrects the deviation based on the determined deviation direction, using the second thermal lens optical power as a base reference value, and combining the thermal lens optical power deviation obtained in step 301, to obtain the corrected target thermal lens optical power, as specifically in steps 3041 to 3043.

[0058] The embodiments of the present invention effectively solve the problem of possible deviations in calculating the optical power of a thermal lens from a single dimension, and achieve accurate correction of the optical power of the thermal lens, resulting in a target optical power of the thermal lens that is more in line with actual working conditions.

[0059] Optionally, the processes of steps 3041 to 3043 include: Step 3041: If the deviation direction is positive, the thermal lens optical power deviation is marked as an upward correction deviation; if the deviation direction is negative, the thermal lens optical power deviation is marked as a downward correction deviation.

[0060] Optionally, the adjustable optical compensation device, based on the determined deviation direction, if the deviation direction is positive (i.e., the optical power of the first thermal lens is greater than the optical power of the second thermal lens), indicating that the optical power of the second thermal lens is relatively low and needs to be corrected upwards, then marks the optical power deviation of the thermal lens as the upward correction deviation; if the deviation direction is negative (i.e., the optical power of the first thermal lens is less than the optical power of the second thermal lens), indicating that the optical power of the second thermal lens is relatively high and needs to be corrected downwards, then marks the optical power deviation of the thermal lens as the downward correction deviation.

[0061] Step 3042: Based on the optical power of the second thermal lens as the basic reference value, and based on the upward or downward correction deviation amount, a query and match is performed in conjunction with the preset deviation correction rule table to obtain the correction increment value.

[0062] Optionally, the adjustable optical compensation device uses the optical power of the second thermal lens as a basic reference value, combined with the upward or downward correction deviation amount marked in step 3041, to query and match a preset deviation correction rule table. That is, it first determines the numerical range to which the basic reference value belongs, and then, combining the deviation type (upward or downward correction) and deviation magnitude, finds a unique corresponding correction increment value in the deviation correction rule table. The deviation correction rule table is established and solidified based on a large amount of prior experimental data and engineering experience. The table contains the correlation between different basic reference value ranges, different deviation magnitudes, and corresponding correction increment values. The correction increment value is a specific numerical value used to correct the optical power of the second thermal lens, in units of per meter. During the query and matching process, if the basic reference value or deviation magnitude exceeds the record range in the table, the correction increment value corresponding to the closest record in the table is taken and marked as interpolated supplementary data.

[0063] Step 3043: Correct the optical power of the second thermal lens based on the correction increment value to obtain the optical power of the target thermal lens.

[0064] Optionally, the adjustable optical compensation device calculates the obtained correction increment value and the obtained optical power of the second thermal lens, that is, it adds the correction increment value to the optical power of the second thermal lens. If the correction increment value is positive, it indicates that the optical power of the second thermal lens is corrected upward; if the correction increment value is negative, it indicates that the optical power of the second thermal lens is corrected downward. Finally, the effective information of the optical power of the first thermal lens is integrated, so that the corrected target optical power of the thermal lens is more in line with the actual state of the thermal lens under the current working conditions.

[0065] The embodiments of the present invention effectively integrate the effective information of two types of thermal lens optical power, and finally obtain a target thermal lens optical power that is more in line with the actual working conditions, thereby further improving the accuracy of thermal lens optical power quantification.

[0066] Optionally, the processes of steps 401 to 405 include: Step 401: The current equivalent total optical power of the resonant cavity is obtained by superimposing the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity.

[0067] Optionally, the adjustable optical compensation device superimposes the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, that is, adds the two values ​​together to obtain the current equivalent total optical power of the resonant cavity, in units of per meter.

[0068] In one embodiment, it is assumed that the optical power of the target thermal lens is 0.86 per meter, and the fixed optical power of the pre-cured gain crystal concave end face is -0.5 per meter. The adjustable optical compensation device performs superposition calculation: 0.86 per meter + (-0.5 per meter) = 0.36 per meter, which is the current equivalent total optical power of the resonant cavity.

[0069] Step 402: Based on the current equivalent total optical power and the allowable range of the total optical power of the resonant cavity under the preset stability margin conditions, determine whether the current equivalent total optical power is within the allowable range, and obtain the judgment result.

[0070] Optionally, the adjustable optical compensation device obtains the allowable range of the total optical power of the resonant cavity under preset stability margin conditions. The stability margin conditions are constraints ensuring stable operation of the resonant cavity. The allowable range of the total optical power is a unified intersection interval determined based on a cavity length range of 200 mm to 300 mm and a stability margin threshold of 0.1 to 0.2, ranging from 0.513 per meter to 4.558 per meter, and is pre-stored in the adjustable optical compensation device or the laser. The adjustable optical compensation device compares the current equivalent total optical power with this allowable range, determining whether it is greater than or equal to the lower limit of the allowable range and less than or equal to the upper limit. The result obtained is the determination result.

[0071] Continuing with the above embodiment, the current equivalent total optical power is 0.36 per meter, and the preset allowable range of total optical power is 0.513 per meter to 4.558 per meter. The adjustable optical compensation device compares and finds that 0.36 per meter is less than the lower limit of 0.513 per meter, so the judgment result is that it is not within the allowable range; if the current equivalent total optical power is 1.2 per meter, which is within the allowable range, then the judgment result is that it is within the allowable range.

[0072] Step 403: If the judgment result is within the allowable range of total optical power, then the empty compensation lens with zero optical power is determined as the target compensation lens; if the judgment result is not within the allowable range, then the excess between the current equivalent total optical power and the upper limit of the allowable range or the deficiency between the current equivalent total optical power and the lower limit of the allowable range is calculated to obtain the negative compensation requirement or the positive compensation requirement, respectively.

[0073] Optionally, if the adjustable optical compensation device determines that the total optical power is within the allowable range, it indicates that no additional compensation is needed to ensure the stability of the resonant cavity. Therefore, the empty compensation lens with zero optical power is directly identified as the target compensation lens. An empty compensation lens refers to a position on the mirror wheel without an actual lens, whose equivalent optical power is zero. If the adjustable optical compensation device determines that the total optical power is not within the allowable range, it further calculates the compensation requirement. Specifically, if the current equivalent total optical power is greater than the upper limit of the allowable range, it indicates that the optical power is too strong. In this case, the difference between the current equivalent total optical power and the upper limit is calculated, and this difference is the negative compensation requirement, which corresponds to the need to introduce a compensation lens with negative optical power to offset it. If the current equivalent total optical power is less than the lower limit of the allowable range, it indicates that the optical power is insufficient. In this case, the difference between the lower limit of the allowable range and the current equivalent total optical power is calculated, and this difference is the positive compensation requirement, which corresponds to the need to introduce a compensation lens with positive optical power to supplement it.

[0074] Continuing with the above embodiment, assuming the judgment result of step 402 is within the allowable range, the adjustable optical compensation device determines the empty compensation lens as the target compensation lens; assuming the judgment result of step 402 is not within the allowable range, the adjustable optical compensation device starts calculating the compensation requirement. That is, if the current equivalent total optical power is 5.0 per meter (greater than the upper limit of 4.558 per meter), according to 5.0 per meter - 4.558 per meter = 0.442 per meter, the negative compensation requirement is 0.442 per meter; if the current equivalent total optical power is 0.36 per meter (less than the lower limit of 0.513 per meter), according to 0.513 per meter - 0.36 per meter = 0.153 per meter, the positive compensation requirement is 0.153 per meter.

[0075] Step 404: Based on the negative or positive compensation demand, and combined with the optical power of multiple preset compensation lenses, a traversal is performed to select all candidate compensation lenses whose optical power signs are consistent with the direction of the compensation demand and whose absolute values ​​are less than or equal to the compensation demand. The candidate compensation lens with the largest absolute value of optical power is determined as the preliminary compensation lens.

[0076] Optionally, the adjustable optical compensation device, based on the obtained negative or positive compensation demand, iterates through multiple pre-stored preset compensation lenses corresponding to optical powers. These preset compensation lenses include plano-convex lenses (positive optical power) and plano-concave lenses (negative optical power), whose optical power values ​​are pre-measured and fixed. The device then filters these preset compensation lenses based on the following criteria: the sign of the optical power of the compensation lens is consistent with the direction of the compensation demand (positive compensation demand corresponds to a positive optical power lens, and negative compensation demand corresponds to a negative optical power lens), and the absolute value of the optical power of the compensation lens is less than or equal to the compensation demand. All compensation lenses meeting these conditions are selected as candidate compensation lenses. If multiple candidate compensation lenses exist, the one with the largest absolute value of optical power is selected as the initial compensation lens. This is because the compensation lens with the largest absolute value can maximize the compensation demand, making the compensated optical power closer to the allowable range.

[0077] Continuing with the above embodiment, assuming the positive compensation requirement is 0.153 per meter, the optical powers of the pre-set compensation lenses (plano-convex lenses) are 0.1 per meter, 0.15 per meter, and 0.2 per meter. The adjustable optical compensation device traverses and filters out candidate compensation lenses with positive optical powers and absolute values ​​less than or equal to 0.153 per meter, namely plano-convex lenses of 0.1 per meter and 0.15 per meter. The plano-convex lens with the largest absolute value is 0.15 per meter, therefore it is determined as the initial compensation lens.

[0078] Assuming a negative compensation requirement of 0.442 per meter, the optical powers of the pre-set compensation lenses (plano-concave lenses) are -0.3 per meter, -0.4 per meter, and -0.5 per meter. The adjustable optical compensation device iterates through the lenses and selects candidate lenses with negative signs and absolute values ​​less than or equal to 0.442 per meter, including -0.3 per meter and -0.4 per meter. The plano-concave lens with the largest absolute value of -0.4 per meter is then selected as the initial compensation lens.

[0079] Step 405: The optical power of the compensation lens based on the preliminary compensation lens is superimposed with the current equivalent total optical power to obtain the first net optical power after compensation. The first net optical power is then verified again against the allowable range of the total optical power of the resonant cavity in the stability margin condition. If it falls within the allowable range, the preliminary compensation lens is determined as the target compensation lens.

[0080] Optionally, the adjustable optical compensation device algebraically superimposes the obtained optical power of the preliminary compensation lens with the current equivalent total optical power obtained in step 401 to obtain the first net optical power after compensation. Then, this first net optical power is re-verified against the allowable range of the total optical power of the resonant cavity in the preset stability margin conditions to determine whether it falls within the allowable range. If the first net optical power is greater than or equal to the lower limit of the allowable range and less than or equal to the upper limit, it indicates that the preliminary compensation lens can enable the resonant cavity to meet the stability requirements; therefore, this preliminary compensation lens is directly determined as the target compensation lens.

[0081] Continuing with the above embodiment, the current equivalent total optical power is 0.36 per meter, the optical power of the initial compensation lens is 0.15 per meter, and the preset allowable range of total optical power is 0.513 per meter to 4.558 per meter. The adjustable optical compensation device calculates the first net optical power after compensation to be 0.36 per meter + 0.15 per meter = 0.51 per meter. Verification shows that 0.51 per meter is close to but not completely within the allowable range; if the optical power of the initial compensation lens is 0.16 per meter, the first net optical power after superposition is 0.36 per meter + 0.16 per meter = 0.52 per meter, which falls within the allowable range. Therefore, the plano-convex lens with an optical power of 0.16 per meter is determined as the target compensation lens.

[0082] Step 406: If the first net optical power does not fall within the allowable range of the total optical power of the resonant cavity under the stable margin condition, then the optical power of the compensation lens corresponding to the multiple preset compensation lenses is re-traversed. For each preset compensation lens, its compensation lens optical power is algebraically added to the current equivalent total optical power to obtain the compensated second net optical power.

[0083] Optionally, if the adjustable optical compensation device finds that the net optical power does not fall within the allowable range of the total optical power, it indicates that the initial compensation lens has failed to meet the stability requirements. Therefore, it re-traverses the optical power of the compensation lens corresponding to all preset compensation lenses, and for each preset compensation lens, it algebraically adds its optical power to the current equivalent total optical power obtained in step 401 (i.e., directly sums them) to obtain the second net optical power after compensation for each preset compensation lens.

[0084] Continuing with the above embodiment, the current equivalent total optical power is 0.36 per meter, and the optical powers of the preset compensation lenses are 0.1 per meter, 0.15 per meter, 0.16 per meter, -0.2 per meter, and -0.3 per meter, respectively. The adjustable optical compensation device calculates the second net optical power one by one to obtain: 0.36 per meter + 0.1 per meter = 0.46 per meter, 0.36 per meter + 0.15 per meter = 0.51 per meter, 0.36 per meter + 0.16 per meter = 0.52 per meter, 0.36 per meter + (-0.2 per meter) = 0.16 per meter, and 0.36 per meter + (-0.3 per meter) = 0.06 per meter, thus obtaining five sets of second net optical powers.

[0085] Step 407: Calculate the absolute distance based on the second net optical power and the nearest boundary of the allowable range of total optical power, and determine the preset compensation lens with the smallest calculated absolute distance as the target compensation lens. If multiple preset compensation lenses correspond to the same minimum absolute distance, select the preset compensation lens with the smallest index number as the final target compensation lens.

[0086] Optionally, the adjustable optical compensation device calculates the absolute distance based on each obtained second net optical power, combined with the nearest boundary of the allowable range of total optical power. The rules for calculating the absolute distance are as follows: if the second net optical power is less than the lower limit of the allowable range, the nearest boundary is the lower limit, and the absolute distance is the absolute value of the difference between the lower limit and the second net optical power; if the second net optical power is greater than the upper limit of the allowable range, the nearest boundary is the upper limit, and the absolute distance is the absolute value of the difference between the second net optical power and the upper limit; if the second net optical power is within the allowable range, the absolute distance is zero. Then, the adjustable optical compensation device compares all absolute distances and identifies the preset compensation lens corresponding to the second net optical power with the smallest absolute distance, determining it as the target compensation lens. If multiple preset compensation lenses have the same minimum absolute distance, they are sorted according to their index number (the index number is a fixed number for each lens station on the mirror wheel, increasing sequentially from the beginning), and the preset compensation lens with the smallest index number is selected as the final target compensation lens.

[0087] Continuing with the above embodiments, the allowable range of total optical power is 0.513 per meter to 4.558 per meter. The second net optical power obtained in step 406 is 0.46 per meter, 0.51 per meter, 0.52 per meter, 0.16 per meter, and 0.06 per meter, respectively. The adjustable optical compensation device calculates the absolute distances of each value as follows: 0.513 per meter - 0.46 per meter = 0.053 per meter, 0.513 per meter - 0.51 per meter = 0.003 per meter, 0.52 per meter - 0.513 per meter = 0.007 per meter, 0.513 per meter - 0.16 per meter = 0.353 per meter, and 0.513 per meter - 0.06 per meter = 0.453 per meter. The absolute distance corresponding to 0.51 per meter is the smallest, which is 0.003 per meter. The corresponding compensation lens power is 0.15 per meter, so this lens is determined as the target compensation lens. If there are two second net power corresponding to an absolute distance of 0.003 per meter, and the corresponding compensation lens index numbers are three and four respectively, then the compensation lens with index number three is selected as the final target compensation lens.

[0088] This invention accurately obtains the equivalent optical power state of the current resonant cavity by superimposing the optical power of the target thermal lens with the fixed optical power. It then determines whether compensation is needed based on a preset allowable range, thus clarifying the necessity of compensation. Based on the determination result, it flexibly selects vacant lenses or calculates the compensation requirement, achieving adaptation to different scenarios. Candidate lenses are screened according to compensation requirements, and the optimal preliminary compensation lens is selected to maximize the fit to the compensation requirements. Subsequently, secondary verification ensures the effectiveness of the preliminary compensation lens. Finally, when the preliminary compensation fails to meet the standard, the optimal compensation lens is selected through traversal calculations and distance comparisons, ensuring the reliability of the compensation. This accurately determines the target compensation lens that enables the resonant cavity to meet the stability margin requirements, effectively avoiding the limitations of a fixed concave crystal adapting to a single working condition.

[0089] Furthermore, the adjustable optical compensation device for a laser resonator provided by the present invention will be described below. The adjustable optical compensation device for a laser resonator described below and the adjustable optical compensation method for a laser resonator described above can be referred to in correspondence with each other.

[0090] Optional, refer to Figure 2 , Figure 2 This is a schematic diagram of the adjustable optical compensation device for a laser resonator provided by the present invention. The adjustable optical compensation device for a laser resonator includes: The data acquisition module 210 is used to acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; The thermal lens optical power determination module 220 is used to determine the first thermal lens optical power under the current operating condition based on the operating condition parameters and a preset parameter optical power mapping table, and to determine the second thermal lens optical power under the current operating condition based on the current thermal state data and a preset thermo-optical conversion mapping table. Deviation correction module 230 is used to perform deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens to obtain the corrected target optical power of the thermal lens. The compensation lens screening module 240 is used to determine the target compensation lens based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses. The lens switching and interlocking control module 250 is used to switch the target compensation lens to the working position in the optical path of the resonant cavity based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, and release the interlocking restriction on the laser's operating state based on the target compensation lens's positioning signal, so that the laser operates according to the current operating parameters.

[0091] This invention provides an embodiment of the invention that obtains the first thermal lens optical power by combining acquired operating condition parameters with a preset parameter focal power mapping table, and obtains the second thermal lens optical power by combining acquired current thermal state data with a preset thermo-optical conversion mapping table. This achieves preliminary quantification of the thermal lens optical power from different dimensions, and corrects for deviations between the first and second thermal lens optical powers to obtain a target thermal lens optical power that more closely matches the actual operating conditions. This solves the problem of optical power calculation deviations that may occur due to a single data source. Furthermore, by combining the target thermal lens optical power, the fixed optical power of the concave end face of the gain crystal, and preset stability margin conditions and the optical power of multiple compensation lenses, the invention accurately selects the lenses that can harmonize the optical power of the target thermal lens. The target compensation lens, which meets the stability requirements of the resonant cavity, avoids the limitation of fixed concave crystals that are only suitable for a single working condition. Finally, the target compensation lens is automatically switched to the working position by rotating the mirror wheel assembly. After it is in position, the interlock restriction is released, allowing the laser to operate according to the current working condition. This replaces manual operation and improves switching efficiency and repeatability. In summary, it not only solves the problem of resonant cavity instability caused by over-compensation under low power / low frequency conditions, but also optimizes the mode volume utilization rate under high power / high frequency conditions. At the same time, it adapts to the need for frequent switching of working parameters, achieving the technical effect of stable laser output power, good beam quality, and efficient and reliable switching, thus meeting the high precision requirements of laser output.

[0092] Please see Figure 3 , Figure 3 An embodiment diagram of an electronic device provided in accordance with the present invention. For example... Figure 3As shown, this embodiment of the invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it performs the following steps: Acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; Based on the operating condition parameters and a preset parameter focal length mapping table, the first thermal lens optical focal length under the current operating condition is determined, and based on the current thermal state data and a preset thermo-optical conversion mapping table, the second thermal lens optical focal length under the current operating condition is determined. The target thermal lens optical power is obtained by performing deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses, the target compensation lens is determined. Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

[0093] Please see Figure 4 , Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with an embodiment of the present invention is shown. Figure 4 As shown, this embodiment provides a computer-readable storage medium 400 on which a computer program 311 is stored. When the computer program 311 is executed by a processor, it performs the following steps: Acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; Based on the operating condition parameters and a preset parameter focal length mapping table, the first thermal lens optical focal length under the current operating condition is determined, and based on the current thermal state data and a preset thermo-optical conversion mapping table, the second thermal lens optical focal length under the current operating condition is determined. The target thermal lens optical power is obtained by performing deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses, the target compensation lens is determined. Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

[0094] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to perform the adjustable optical compensation method for a laser resonator provided by the above methods, the method comprising: Acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; Based on the operating condition parameters and a preset parameter focal length mapping table, the first thermal lens optical focal length under the current operating condition is determined, and based on the current thermal state data and a preset thermo-optical conversion mapping table, the second thermal lens optical focal length under the current operating condition is determined. The target thermal lens optical power is obtained by performing deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses, the target compensation lens is determined. Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

[0095] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0096] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for adjustable optical compensation of a laser resonator, characterized in that, include: Acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; Based on the operating condition parameters and a preset parameter focal length mapping table, the first thermal lens optical focal length under the current operating condition is determined, and based on the current thermal state data and a preset thermo-optical conversion mapping table, the second thermal lens optical focal length under the current operating condition is determined. The target thermal lens optical power is obtained by performing deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens. Based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lens corresponding to multiple preset compensation lenses, the target compensation lens is determined. Based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, the target compensation lens is switched to the working position in the optical path of the resonant cavity, and based on the positioning signal of the target compensation lens, the interlocking restriction on the laser's operating state is released, so that the laser operates according to the current operating parameters.

2. The adjustable optical compensation method for a laser resonator according to claim 1, characterized in that, The operating parameters include repetition frequency, average power, duty cycle, and cooling temperature; The determination of the first thermal lens optical power under the current operating condition based on operating condition parameters and a preset parameter focal length mapping table includes: Based on the repetition frequency, average power, duty cycle and cooling temperature as a joint index, a search and matching is performed with the parameter focal value mapping table to obtain the first matching result; If the first matching result is that there is a completely consistent calibration record, then the thermal lens power value corresponding to the calibration record is determined as the first thermal lens power. If the first matching result is that there is no completely consistent calibration record, then multiple calibrated working points adjacent to the working condition parameters are identified in the parameter power mapping table to obtain the interpolation reference point set. Based on the repetition frequency, average power, duty cycle, and cooling temperature corresponding to each calibrated operating point in the interpolation reference point set, and their associated stored thermal lens power values, multiple sets of corresponding data pairs of four-dimensional operating parameters and one-dimensional thermal lens power are constructed. Multilinear interpolation is performed on the operating parameters in the corresponding data pairs to obtain continuous optical power estimates. Based on the estimated optical power value and the physical reasonable range of the preset thermal lens optical power, the first thermal lens optical power under the current operating condition is determined.

3. The adjustable optical compensation method for a laser resonator according to claim 2, characterized in that, The step of determining the first thermal lens power under the current operating condition based on the estimated power value and a preset physically reasonable range of thermal lens power includes: Based on the optical power estimate and the physical reasonable range, a matching judgment is made. If the optical power estimate is within the physical reasonable range, the value is determined as the first thermal lens optical power. If the optical power estimate is not within the physical reasonable range, all thermal lens optical power values ​​corresponding to the interpolation reference point set are matched with the physical reasonable range to obtain all calibrated working points within the physical reasonable range. Based on the thermal lens power values ​​corresponding to all calibrated operating points within the physically reasonable range, the calibrated operating point corresponding to the thermal lens power value closest to the estimated power value is selected, and the thermal lens power value associated with and stored at this calibrated operating point is determined as the first thermal lens power.

4. The adjustable optical compensation method for a laser resonator according to claim 1, characterized in that, The deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens to obtain the corrected target optical power includes: The absolute difference between the optical power of the first thermal lens and the optical power of the second thermal lens is calculated to obtain the optical power deviation of the thermal lens. Based on the comparison and judgment of the optical power deviation of the thermal lens with the preset deviation tolerance threshold, if the optical power deviation of the thermal lens is less than or equal to the deviation tolerance threshold, then the optical power of the second thermal lens is determined as the target optical power of the thermal lens. If the optical power deviation of the thermal lens is greater than the deviation tolerance threshold, the deviation direction is determined based on the relative magnitude relationship between the optical power of the first thermal lens and the optical power of the second thermal lens; the deviation direction includes positive deviation or negative deviation. Based on the deviation direction, the optical power of the second thermal lens is used as a basic reference value, and the deviation of the optical power of the thermal lens is combined with the deviation amount to perform deviation correction, so as to obtain the corrected target optical power of the thermal lens.

5. The adjustable optical compensation method for a laser resonator according to claim 4, characterized in that, The step of performing deviation correction based on the deviation direction, using the second thermal lens optical power as a basic reference value and combining it with the thermal lens optical power deviation amount, to obtain the corrected target thermal lens optical power includes: If the deviation direction is positive, the thermal lens optical power deviation is marked as an upward correction deviation; if the deviation direction is negative, the thermal lens optical power deviation is marked as a downward correction deviation. Using the optical power of the second thermal lens as the basic reference value, and based on the upward or downward correction deviation amount, a query and match are performed in conjunction with a preset deviation correction rule table to obtain the correction increment value. The optical power of the second thermal lens is corrected based on the correction increment value to obtain the optical power of the target thermal lens.

6. The adjustable optical compensation method for a laser resonator according to claim 1, characterized in that, The determination of the target compensation lens, based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with preset stability margin conditions and the optical power of the compensation lenses corresponding to multiple preset compensation lenses, includes: The current equivalent total optical power of the resonant cavity is obtained by superimposing the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity. Based on the current equivalent total optical power and the allowable range of the total optical power of the resonant cavity under the preset stability margin conditions, it is determined whether the current equivalent total optical power is within the allowable range, and the determination result is obtained. If the judgment result is within the allowable range of total optical power, then the empty compensation lens with zero optical power is determined as the target compensation lens; if the judgment result is not within the allowable range, then the excess between the current equivalent total optical power and the upper limit of the allowable range or the deficiency between the current equivalent total optical power and the lower limit of the allowable range is calculated to obtain the negative compensation requirement or the positive compensation requirement, respectively. Based on the negative compensation demand or the positive compensation demand, and combined with the optical power of the compensation lens corresponding to multiple preset compensation lenses, the candidate compensation lenses with the same optical power sign as the compensation demand direction and whose absolute value is less than or equal to the compensation demand are selected. The candidate compensation lens with the largest absolute value of optical power is determined as the preliminary compensation lens. The optical power of the compensated lens based on the preliminary compensation lens is superimposed with the current equivalent total optical power to obtain the compensated net optical power. The net optical power is then verified again against the allowable range of the total optical power of the resonant cavity in the stability margin condition. If it falls within the allowable range, the preliminary compensation lens is determined as the target compensation lens.

7. The adjustable optical compensation method for a laser resonator according to claim 6, characterized in that, If the net optical power does not fall within the allowable range of the total optical power of the resonant cavity under the stability margin condition, the optical power of the compensation lens corresponding to the multiple preset compensation lenses is re-traversed. For each preset compensation lens, its compensation lens optical power is algebraically added to the current equivalent total optical power to obtain the compensated second net optical power. The absolute distance is calculated based on the second net optical power and the nearest boundary of the total optical power allowable range, and the preset compensation lens with the smallest calculated absolute distance is determined as the target compensation lens.

8. An adjustable optical compensation device for a laser resonator, characterized in that, The method for adjustable optical compensation of a laser resonator as described in any one of claims 1 to 7; the adjustable optical compensation device for the laser resonator comprises: The data acquisition module is used to acquire the operating parameters of the target laser and the current thermal state data of the gain crystal; The thermal lens optical power determination module is used to determine the first thermal lens optical power under the current operating condition based on the operating condition parameters and a preset parameter optical power mapping table, and to determine the second thermal lens optical power under the current operating condition based on the current thermal state data and a preset thermo-optical conversion mapping table. The deviation correction module is used to perform deviation correction based on the optical power of the first thermal lens and the optical power of the second thermal lens to obtain the corrected target optical power of the thermal lens. The compensation lens selection module is used to determine the target compensation lens based on the optical power of the target thermal lens and the fixed optical power of the concave end face of the gain crystal in the resonant cavity, combined with the preset stability margin conditions and the optical power of the compensation lenses corresponding to multiple preset compensation lenses. The lens switching and interlocking control module is used to switch the target compensation lens to the working position in the optical path of the resonant cavity based on the target compensation lens combined with the rotating mirror wheel assembly in the resonant cavity, and release the interlocking restriction on the laser's operating state based on the target compensation lens's positioning signal, so that the laser can operate according to the current operating parameters.

9. An electronic device, characterized in that, include: Memory, used to store computer software programs; A processor for reading and executing the computer software program, wherein when the processor executes the computer software program, it implements the adjustable optical compensation method for a laser resonator as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, characterized in that, The storage medium stores a computer software program, which, when executed by a processor, implements the adjustable optical compensation method for a laser resonator as described in any one of claims 1 to 7.

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