Laser light intensity stabilizing method and device

Abstract

The invention provides a laser light intensity stabilizing method and device, and relates to the technical field of laser regulation and control. According to the method, high-precision, rapid and stable control over the femtosecond laser light intensity is achieved through cooperation of a polarization optical element combination and a self-adaptive PID control algorithm. The device comprises a light path system and a control system, the light path system is composed of a broadband half-wave plate, a Glan-Taylor prism and a spectroscope, and the control system achieves feedback adjustment based on a photoelectric detector and an upper computer. By dynamically optimizing the gain parameter of the PID algorithm, the control strategy can be adaptively adjusted according to the error signal, and the response speed and the stability are both considered. According to the invention, the technical problems of limited adjustment precision and insufficient response speed in the existing laser light intensity stabilization technology can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser control, in particular to a laser intensity stabilizing method and device. BACKGROUND

[0002] Femtosecond laser has irreplaceable role in the field of atomic and molecular dynamics research, precision spectrum measurement, biomedical imaging and ultrafast processing due to its ultra-short pulse width and extremely high peak power. However, femtosecond laser faces a key challenge in practical application: its light intensity is easily disturbed by environmental factors such as spatial distribution characteristics, air humidity and temperature fluctuation in the propagation process, mechanical vibration and power noise, resulting in significant power jitter. Such jitter will cause experimental data drift or measurement error in long-term experiments, especially in the field of atomic and molecular research which requires extremely high light intensity stability, and will mask high-order nonlinear phenomena, seriously restricting the reliability of experimental results.

[0003] In the prior art, the following methods are usually used to realize laser intensity stabilization: adjusting the output light intensity by rotating a polarizer, adjusting an aperture or a filter, etc. However, such methods mostly rely on manual operation, and the adjustment precision and response speed are limited, which cannot meet the demand of rapid change of femtosecond light pulses. Active adjustment of laser intensity is realized by using an electro-optic modulator or an acousto-optic modulator, which has a certain response speed, but such devices are expensive and complex in structure, and require high optical path stability of the system, and additional dispersion and phase distortion are easily introduced under femtosecond pulses. Therefore, how to develop a technical solution capable of adapting to complex experimental environment and realizing high-precision, rapid self-feedback real-time stable control of femtosecond laser intensity is a technical problem to be solved in the field. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a laser intensity stabilizing method and device, to solve the technical problems of limited adjustment precision and response speed of laser intensity stabilization in the prior art.

[0005] The technical solution adopted by the present application is that high-precision, rapid stable control of femtosecond laser intensity is realized through the cooperation of polarized optical element combination and adaptive PID control algorithm.

[0006] In the first implementation mode, a laser intensity stabilizing method comprises: real-time acquisition of laser intensity; comparing the laser intensity with a target light intensity to generate an error signal; inputting the error signal into a PID controller, the PID controller generating a control quantity according to a current gain coefficient; converting the control quantity into a driving instruction through numerical proportion; According to the error signal and its change, the gain coefficient of the PID controller is adjusted in real time.

[0007] Further, according to the error signal and its change, the gain coefficient of the PID controller is adjusted in real time, including: According to the current error signal and historical error signal, a filtered error change rate is calculated. According to the error signal and the filtered error change rate, a learning rate and a leakage matrix are updated in real time. The filtered error change rate is combined with the learning rate and the leakage matrix at the current time to update a parameter vector containing the gain coefficient according to a gain coefficient adaptive algorithm.

[0008] Further, the gain coefficient adaptive algorithm is specifically: where k represents the current sampling time, represents a parameter vector, represents a learning rate, represents a channel gain estimate value, represents an error change rate, represents a leakage matrix, represents a regression vector, represents a prior parameter vector.

[0009] Further, according to the error signal and the filtered error change rate, a learning rate and a leakage matrix are updated in real time, including: In response to the absolute value of the error signal being greater than a preset fast convergence threshold, the learning rate is increased and the leakage matrix is decreased according to the filtered error change rate; In response to the absolute value of the error signal being less than a preset stable threshold, the learning rate is decreased and the leakage matrix is increased according to the filtered error change rate; In response to the absolute value of the error signal being between the fast convergence threshold and the stable threshold, the learning rate and the leakage matrix remain unchanged.

[0010] Further, the learning rate is increased according to the following formula: where, represents a learning rate, represents an initial learning rate, and α represents a fast convergence adjustment coefficient, represents a filtered error change rate, represents a fast convergence value. The learning rate is decreased according to the following formula: wherein, represents a learning rate, represents an initial learning rate, represents a stable adjustment coefficient, represents a filter error change rate, represents a stable threshold.

[0011] Further, the leakage matrix is reduced according to the formula as follows: wherein, represents a leakage matrix, represents a basic leakage matrix, represents a fast convergence adjustment coefficient adjustment coefficient, represents a filter error change rate, represents a fast convergence value; The leakage matrix is increased according to the formula as follows: wherein, represents a leakage matrix, represents a basic leakage matrix, represents a stable adjustment coefficient, represents a filter error change rate, represents a stable threshold.

[0012] In combination with the first implementation manner, in the second implementation manner, a laser intensity stabilizing device includes an optical path system and a control system. The optical path system is configured to stabilize laser intensity. The control system is configured to control the optical path system by using the above method.

[0013] Further, the optical path system includes a wideband half-wave plate, a Glan-Taylor prism, a beam splitter, and a stepping motor rotating table. The stepping motor rotating table is connected with the wideband half-wave plate and adjusts the rotating angular velocity and rotating angle of the wideband half-wave plate according to the driving instruction of the control system. The wideband half-wave plate, the Glan-Taylor prism, and the beam splitter are located on the same optical axis, and the laser passes through the wideband half-wave plate, the Glan-Taylor prism, and the beam splitter in sequence. The laser passes through the beam splitter to divide into transmitted main light and reflected monitoring light, the reflected monitoring light is output to the control system as feedback laser, and the transmitted main light is used as a stable laser source for subsequent experiments.

[0014] Further, the control system includes a photodetector and an upper computer. The photodetector acquires the feedback laser and converts it into an electrical signal, which is then output to the host computer. The host computer converts the electrical signal into a drive command and outputs it to the optical path system.

[0015] Furthermore, the host computer includes: The acquisition module is used to acquire laser light intensity in real time; An error calculation module is used to compare the laser intensity with the target intensity and generate an error signal. The PID control module is used to input the error signal into the PID controller, which generates a control quantity based on the current gain coefficient. The drive module is used to convert the control quantity into drive instructions through numerical scaling. The dynamic adjustment module is used to adjust the gain coefficient of the PID controller in real time based on the error signal and its changes.

[0016] As can be seen from the above technical solution, the beneficial technical effects of the present invention are as follows: 1. The laser intensity stabilization method employed in this invention introduces a dynamic adjustment mechanism for the learning rate and leakage matrix. When a sudden change in light intensity is detected, it automatically enters a fast recovery mode to prioritize response speed; when the light intensity tends to stabilize, it switches to a fine adjustment mode to prioritize stability. This intelligent adaptive capability enables it to cope with the inherent rapid jitter of femtosecond lasers, thereby improving the stability of laser intensity.

[0017] 2. Compared with traditional light intensity stabilization schemes, the laser light intensity stabilization device used in this invention avoids the adverse effects that complex modulators may have on the quality of femtosecond laser pulses, making the device more universal and operable in laboratory environments. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0019] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention; Figure 2 This is a structural diagram of the device according to Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the program front panel of Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the program back panel of Embodiment 2 of the present invention; Figure 5 This is a graph showing the experimental measurement data of laser light intensity changing over time in Embodiment 2 of the present invention. Detailed Implementation

[0020] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0021] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0022] Example 1 This embodiment provides a method for stabilizing laser light intensity. The working principle of Embodiment 1 is explained in detail below: The method flowchart of this embodiment is as follows: Figure 1 As shown, it includes: Real-time acquisition of laser light intensity.

[0023] The laser intensity is compared with the target intensity to obtain the error signal: in, Indicates the error signal. Indicates the target light intensity. Indicates the intensity of the laser light.

[0024] The error signal is input to the PID controller, which generates a control quantity based on the current gain coefficient.

[0025] The control quantity is converted into a driving command through numerical scaling. The stepper motor rotary table adjusts the angle of the broadband half-wave plate according to the driving command, changes the angle between the polarization direction of the incident laser and the Glan Taylor prism, and thus adjusts the output light intensity.

[0026] The gain coefficient of the PID controller is adjusted in real time based on the error signal and its changes.

[0027] In this embodiment, the PID algorithm is further defined as follows: in, Indicates the control quantity. Indicates proportional gain. Indicates integral gain. Represents differential gain. This indicates an error signal.

[0028] In this embodiment, the PID algorithm is further dynamically optimized, including: Calculate the error rate of change based on the error signal: The learning rate and leakage matrix are introduced to discretize and update the gain coefficients of the PID algorithm: Where k represents the current sampling time, Represents a parameter vector. Indicates the learning rate. This represents the estimated channel gain. Indicates the rate of change of error. Represents the leakage matrix. Represents the regression vector. This represents the prior parameter vector.

[0029] In response to the absolute value of the error signal being greater than a preset fast convergence threshold At the same time, the learning rate is increased and the leakage matrix is ​​decreased according to the rate of change of the filtering error, so as to accelerate the update speed of the PID gain coefficients, wherein the learning rate is increased according to the following formula: in, Indicates the learning rate. This represents the initial learning rate, and α represents the fast convergence adjustment coefficient, used to amplify the learning rate in fast convergence mode. The larger α is, the greater the increase in the learning rate and the faster the parameters are updated. Indicates the rate of change of filtering error. Indicates the value of fast convergence; The leakage matrix is ​​reduced according to the following formula: in, Represents the leakage matrix. Represents the basic leakage matrix. This represents the fast convergence adjustment coefficient, used to reduce the leakage matrix. The larger the value, the greater the reduction in the leakage matrix, and the greater the degree of freedom in parameter updates. Indicates the rate of change of filtering error. This represents the value of rapid convergence.

[0030] In response to the absolute value of the error signal being less than a preset stability threshold At the same time, the learning rate is decreased and the leakage matrix is ​​increased according to the change in the filtering error, so that the PID gain coefficient tends to stabilize, wherein the learning rate is decreased according to the following formula: in, Indicates the learning rate. This represents the initial learning rate. This represents the stabilization adjustment coefficient, used to reduce the learning rate. The larger η is, the greater the reduction in the learning rate, and the slower the parameter updates. Indicates the rate of change of filtering error. This represents the stability threshold.

[0031] Increase the leakage matrix according to the following formula: in, Represents the leakage matrix. Represents the basic leakage matrix. This represents the stability adjustment coefficient, used to increase the leakage matrix. The larger the value, the greater the increase in the leakage matrix, and the higher the stability of parameter updates. Indicates the rate of change of filtering error. This represents the stability threshold.

[0032] When the absolute value of the error signal is between the fast convergence threshold and the stability threshold, the learning rate and the leakage matrix are kept unchanged to prevent frequent mode switching caused by error fluctuations.

[0033] To avoid amplifying noise through the derivative term, this embodiment employs a filtered derivative. When the stepper motor's angular velocity changes rapidly, the integral term tends to decrease, preventing overshoot due to integral accumulation. Simultaneously, the control output value u(k) is proportionally converted and sent to the stepper motor controller, transforming it into micro-step drive pulses to adjust the half-wave plate angle. The angle change is then detected by the photodetector through optical feedback loop and enters the parameter update for the next cycle. Ultimately, this achieves the PID parameter setting resulting from the algorithm.

[0034] Example 2 In conjunction with Embodiment 1, Embodiment 2 includes a laser intensity stabilization device, the structure of which is shown in the figure below. Figure 2 As shown, it includes an optical path system and a control system.

[0035] The optical path system is used to stabilize the laser intensity; the control system is used to control the optical path system by executing the laser intensity stabilization method in Example 1.

[0036] The optical path system includes a self-feedback loop consisting of a broadband half-wave plate, a Glan Taylor prism, and a beam splitter. The broadband half-wave plate, the GlanTeller prism, and the beam splitter are located on the same optical axis, and the laser passes through the broadband half-wave plate, the GlanTeller prism, and the beam splitter in sequence. The laser beam is split into a transmitted main beam and a reflected monitoring beam by a beam splitter. The reflected monitoring beam is output as a feedback laser to the control system, while the transmitted main beam is linearly polarized light with a fixed polarization direction, which is required for subsequent experiments.

[0037] The control system includes a photoelectric detector, a stepper motor rotary table, and a host computer. The photodetector converts the feedback laser into an electrical signal, which is then digitized by the data acquisition card and output to the host computer. The host computer converts the electrical signal into a drive command and outputs it to the stepper motor rotary table.

[0038] The stepper motor rotary table adjusts the rotational angular velocity and rotational angle of the broadband half-wave plate according to the drive command.

[0039] In this embodiment, the host computer further includes: The acquisition module is used to acquire laser light intensity in real time.

[0040] The error calculation module is used to compare the laser intensity with the target intensity to obtain an error signal.

[0041] The PID control module is used to input the error signal into a discretized positional PID algorithm to generate a control quantity.

[0042] The driving module is used to convert the control quantity into a numerical ratio to generate a driving command for adjusting the output light intensity.

[0043] In this embodiment, the specific implementation process of the device is as follows: The femtosecond pulsed laser enters the self-feedback loop through a broadband half-wave plate. The combined action of the broadband half-wave plate and the Glan Taylor prism polarizer is used to adjust the intensity of the laser light incident into the system and ensure that the intensity of the laser light emitted after passing through the beam splitter is linearly polarized light with a fixed polarization direction, which meets the requirements of subsequent experiments.

[0044] By placing the broadband half-wave plate in the rotation position of the stepper motor rotary table, the long axis angle of the half-wave plate can be adjusted manually and electrically, respectively, and the laser obtains accurate laser intensity after passing through the half-wave plate and polarizer.

[0045] In this example, the broadband half-wave plate is applicable to wavelengths of 600~2700nm, and the polarizer is applicable to wavelengths of 350~2300nm, covering most of the optical wavelengths required by the laboratory.

[0046] A beam splitter is used to separate a small portion of the laser light in the laser path and introduce it into a photodetector. After passing through the beam splitter, the transmitted light is output to the experimental setup, and the reflected light is output to the photodetector.

[0047] In this example, the beam splitter uses a transmission-to-reflection ratio of 9:1, and the reflected laser light is sufficient to induce a light intensity response when it shines on the photodetector.

[0048] The photodetector is a free-space bias detector. The detector is used to receive part of the laser light reflected by the beam splitter. An adjustable center density filter is installed in front of the detector. The transmittance is adjustable from 1% to 50% to adjust the intensity of the laser light entering the photodetector. This ensures that when the incident light intensity is adjusted according to different experimental needs, the photodetector can receive the laser intensity of the center part of the detection response range, obtain a complete laser pulse, and conform to the voltage response curve of the photodetector.

[0049] In this example, different photodetectors are selected according to the laser wavelength required for the experiment. When detecting lower wavelength lasers, a silicon detector is selected, which is suitable for wavelength ranges of 200~1100nm, rise time of 35ns, bandwidth of 10MHz, and detection is performed using a 50Ω load resistor.

[0050] When detecting higher wavelength lasers, an indium gallium arsenide detector is selected, which is suitable for wavelength ranges of 900~2600nm, rise time of 25ns, and bandwidth of 20.6MHz.

[0051] The stepper motor rotary table is fixed in the optical path with a 1-inch center hole for placing a 1-inch diameter broadband half-wave plate. Depending on the experimental needs, the angle of the half-wave plate can be adjusted by manually rotating the adjuster. The rotary table is connected to the corresponding stepper motor controller via a dedicated serial port. The rotational speed and rotation angle of the stepper motor can be manually adjusted by adjusting the parameters on the controller.

[0052] In this example, the stepper motor controller used has a maximum rotation speed of 20° / second, a repeatability of 0.005°, and a drive structure consisting of a turbine and worm gear, making it suitable for experimental optical environments.

[0053] The stepper motor controller is connected to the host computer via a serial port. The secondary development program is imported into LabVIEW, the program running parameters are optimized, and the target parameters are input to control the stepper motor to run in the direction and angular velocity required by the experiment, and to obtain the accurate angle value of the broadband half-wave plate.

[0054] The photodetector converts the laser signal detected by the probe into an electrical signal. The detector also has a BNC female connector, which is connected to the data acquisition card using a dedicated data cable. The electrical signal from the detector is transmitted to the acquisition card, which is then inserted into the PCIe slot of the host computer and connects the data to the LabVIEW program.

[0055] The program's front and back panels are as follows Figure 3 and Figure 4As shown, the photodetector is set to acquire a maximum voltage of 1V, uses DC coupling for transmission, has an input impedance of 50Ω, a minimum sampling rate of 100M, a trigger level of 0.2V, and records are made every 2000 data points acquired. The acquired voltage copy signal is then saved to the corresponding database.

[0056] In this example, when the self-feedback loop is activated and the initial voltage value and jitter range of the photodetector are set, the system uses a PID algorithm to adjust the output signal value, further controlling the angle of the stepper motor to obtain a stable laser light intensity.

[0057] The data acquisition card obtains the light intensity electrical signal collected by the photodetector and displays it on the front panel in the form of a waveform graph. Simultaneously, it calculates the difference between this electrical signal data and a set standard light intensity value, compares it with the jitter range value, and inputs the output value to the input port of LabVIEW's PID toolkit. In this invention, the control flow is further refined into the following stages: First, the photodetector monitors the laser reflected light power in real time and converts it into an analog electrical signal. This signal is then converted into a digital signal by a high-sampling-rate data acquisition card and input to the host computer. In the host computer, a LabVIEW program calculates the difference between the acquired real-time light intensity signal and the set target light intensity value to obtain the light intensity error signal. Subsequently, the program automatically determines whether the error amplitude exceeds the set jitter threshold. If the error is within the allowable range, the current output state is maintained; if it exceeds the threshold, the PID control module is triggered to enter dynamic adjustment mode.

[0058] Furthermore, the PID algorithm module sets three parameters: proportional, integral, and derivative, and dynamically outputs correction values ​​based on the error signal. In this embodiment, based on an adaptive gain adjustment-based PID control strategy, when a rapid rate of change in light intensity or a system response lag is detected, the proportional term is increased and the integral time constant is shortened to improve the response speed; when the system tends to a steady state, the proportional term is decreased and the integral term is increased to prevent oscillations. The algorithm optimization part is implemented using LabVIEW user-defined functions, forming a PID control framework that can self-tune in real time.

[0059] Finally, the PID output is converted into a stepper motor control signal by a numerical proportional converter module. This signal is then recognized by the stepper motor controller and converted into drive pulses. The stepper motor rotary table adjusts the angle of the broadband half-wave plate according to the input signal, thereby changing the angle between the incident polarized light and the polarization direction of the Glan-Taylor prism, achieving precise and continuous adjustment of the laser intensity. After each rotation, the system re-acquires the feedback signal, forming a closed-loop cycle update, achieving real-time self-calibration and stabilization of the laser intensity.

[0060] This dynamic parameter adjustment is driven by the numerical logic module of the LabVIEW program and real-time sampling results, enabling the controller to maintain optimal response under different operating conditions. Compared with fixed-parameter PID, self-tuning PID can automatically optimize control parameters according to environmental changes and feedback trends, achieving a balance between fast response and high stability.

[0061] When testing system stability, after the laser is introduced into the photodetector, an accurate initial light intensity value is measured, and a standard light intensity value of a corresponding magnitude is set. The intensity of the incident laser is manually changed. First, the proportional parameter is adjusted to make the input and output parameters of the control module proportional, and the response speed is accelerated by adjusting the response time. When the output light intensity can initially change with the set value, the integral parameter is adjusted to eliminate steady-state error. This step will lengthen the response time. Finally, the differential parameter is fine-tuned to improve the dynamic stability of the entire feedback loop.

[0062] After adjusting the PID parameters of the entire system, a stable light intensity can be obtained simply by turning on the feedback button during subsequent experiments. Depending on the experimental requirements for different laser light intensities, the center density filter placed in front of the photodetector can be adjusted to ensure that the laser intensity entering the detector remains constant under different light intensities. This eliminates the need to adjust the PID control module parameters every time experimental conditions change.

[0063] When measuring a femtosecond laser with a wavelength of 800 nm, a pulse width of 30 fs, and an intensity of 1 × 10¹⁴ W / cm², the intensity fluctuation can be maintained within 2%, meeting the requirements for stable laser intensity in the laboratory. Specific experimental measurement data of laser intensity changes over time are as follows: Figure 5 As shown.

[0064] 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for stabilizing laser intensity, characterized in that, include: Real-time acquisition of laser light intensity; The laser intensity is compared with the target intensity to generate an error signal; The error signal is input to the PID controller, which generates a control quantity based on the current gain coefficient. The control quantity is converted into a drive command using a numerical ratio; The gain coefficient of the PID controller is adjusted in real time based on the error signal and its changes.

2. The laser intensity stabilization method according to claim 1, characterized in that, Based on the error signal and its changes, the gain coefficient of the PID controller is adjusted in real time, including: Calculate the rate of change of the filtered error based on the current error signal and the historical error signal; The learning rate and leakage matrix are updated in real time based on the error signal and the rate of change of the filtering error. The filter error change rate is combined with the learning rate and leakage matrix at the current moment, and the parameter vector containing the gain coefficient is updated according to the gain coefficient adaptive algorithm.

3. The laser intensity stabilization method according to claim 2, characterized in that, The adaptive gain coefficient algorithm is specifically as follows: Where k represents the current sampling time, Represents a parameter vector. Indicates the learning rate. This represents the channel gain estimate. Indicates the rate of change of error. Represents the leakage matrix. Represents the regression vector. This represents the prior parameter vector.

4. The laser intensity stabilization method according to claim 2, characterized in that, The learning rate and leakage matrix are updated in real time based on the error signal and the rate of change of the filtering error, including: When the absolute value of the error signal is greater than a preset fast convergence threshold, the learning rate is increased and the leakage matrix is ​​decreased according to the rate of change of the filtering error; When the absolute value of the error signal is less than a preset stability threshold, the learning rate is reduced and the leakage matrix is ​​increased according to the change in the filtering error; When the absolute value of the error signal is between the fast convergence threshold and the stability threshold, the learning rate and the leakage matrix remain unchanged.

5. The laser intensity stabilization method according to claim 4, characterized in that, Increase the learning rate according to the following formula: in, Indicates the learning rate. This represents the initial learning rate, and α represents the fast convergence adjustment coefficient (used to amplify the learning rate in fast convergence mode. The larger α is, the greater the increase in the learning rate and the faster the parameters are updated). Indicates the rate of change of filtering error. Indicates the value of fast convergence; The learning rate is reduced according to the following formula: in, Indicates the learning rate. This represents the initial learning rate. This represents the stability adjustment coefficient. Indicates the rate of change of filtering error. This represents the stability threshold.

6. The laser intensity stabilization method according to claim 4, characterized in that, The leakage matrix is ​​reduced according to the following formula: in, Represents the leakage matrix. Represents the basic leakage matrix. This represents the fast convergence adjustment coefficient. Indicates the rate of change of filtering error. Indicates the value of fast convergence; Increase the leakage matrix according to the following formula: in, Represents the leakage matrix. Represents the basic leakage matrix. This represents the stability adjustment coefficient. Indicates the rate of change of filtering error. This represents the stability threshold.

7. A laser intensity stabilization device, characterized in that, Including optical path systems and control systems; The optical path system is used to stabilize the laser beam intensity; The control system is configured to control the optical path system using the method described in any one of claims 1-6.

8. A laser intensity stabilizing device according to claim 7, characterized in that, The optical path system includes a broadband half-wave plate, a Glan Taylor prism, a beam splitter, and a stepper motor rotary table; The stepper motor rotary table is connected to the half-wave plate, and adjusts the rotational angular velocity and rotational angle of the broadband half-wave plate according to the drive command of the control system. The broadband half-wave plate, the GlanTeller prism, and the beam splitter are located on the same optical axis, and the laser passes through the broadband half-wave plate, the GlanTeller prism, and the beam splitter in sequence. The laser beam is split into a transmitted main beam and a reflected monitoring beam by the beam splitter. The reflected monitoring beam is output as a feedback laser to the control system, while the transmitted main beam serves as a stable laser source for subsequent experiments.

9. A laser intensity stabilizing device according to claim 7, characterized in that, The control system includes a photoelectric detector and a host computer; The photodetector acquires the feedback laser and converts it into an electrical signal, which is then output to the host computer. The host computer converts the electrical signal into a drive command and outputs it to the optical path system.

10. A laser intensity stabilizing device according to claim 6, characterized in that, The host computer includes: The acquisition module is used to acquire laser light intensity in real time; An error calculation module is used to compare the laser intensity with the target intensity and generate an error signal. The PID control module is used to input the error signal into the PID controller, which generates a control quantity based on the current gain coefficient. The drive module is used to convert the control quantity into drive instructions through numerical scaling. The dynamic adjustment module is used to adjust the gain coefficient of the PID controller in real time based on the error signal and its changes.

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