Continuous wave Ti sapphire laser power stabilization optimization system and method based on three-mirror mode cleaner

Abstract

The invention discloses a continuous wave Ti sapphire laser power stabilization optimization system and method based on a three-mirror mode cleaner, and the system comprises the steps: a Ti sapphire laser outputs a light beam, the light beam is adjusted through a front-end light path system, at an input mirror of the mode cleaner, a reflection end photoelectric detector receives the fluctuation of light power, the voltage signal is transmitted into an optical power simulation control unit, and the simulation control unit generates a driving voltage of a radio frequency driver according to power fluctuation so as to drive an acousto-optic modulator to perform diffraction efficiency adjustment and further stabilize output power. In the power stabilizing process, the cavity length of the mold cleaner needs to be adjusted through the electro-optical modulator. Compared with a common photoelectric feedback method, the system uses the mode cleaner to replace a common light splitting lens, so that the light current can be reduced under the condition of keeping the same noise level, the noise suppression level of the power stabilization system is further improved, and the output light power stability is improved.

Description

Technical Field

[0001] The invention belongs to the field of continuous wave Ti:Sapphire laser power stabilization system, and in particular relates to a continuous wave Ti:Sapphire laser power stabilization optimization system and method based on a three-mirror mode cleaner. Background Art

[0002] Quantum precision measurements such as precision atomic clocks, quantum extremely weak magnetic field measurements, and atomic spin gyroscopes all require high-power and highly stable lasers as the light source of pumping light. Continuous-wave titanium sapphire lasers are widely used in the above research fields due to their advantages such as high beam quality, low noise, narrow linewidth, and strong tuning capability. Titanium sapphire lasers have a wide radiation spectrum range of 700~1000 nm and excellent transverse mode quality. At the same time, its wavelength can be adjusted to correspond to the transition absorption lines of various alkali metal atoms. As a high-quality laser light source, it plays an important role in quantum precision measurement.

[0003] Taking inertial measurement as an example, in the laser pumping system, the change of the optical power of the pumping light directly affects the polarizability of the subsequent alkali metal atoms, and the change of the polarizability of the alkali metal source will affect the nuclear spin compensation ability and produce magnetic field fluctuation errors. It affects the pumping error and frequency shift error of the longitudinal light, and then affects the accuracy of the inertial measurement scale factor. Therefore, suppressing the laser power fluctuation is of great significance to improve the long-term stability of inertial measurement.

[0004] The current traditional power stabilization method mainly uses a beam splitter to split the laser into two beams. One beam with lower power is detected by a photodetector and used for photoelectric feedback, while the other beam with higher power is used as the output laser. The feedback method can be the current or temperature of the pump source, or an external power suppressor such as an electro-optic modulator or an acousto-optic modulator. This photoelectric feedback method can effectively suppress power fluctuations, but due to the photocurrent threshold limit of the photodetector, there is still room for optimization of power noise. Summary of the invention

[0005] In order to solve the problem that in the traditional Ti:Sapphire laser power stabilization system, the power feedback link is limited by the photocurrent detected by the photodetector, and the power noise still has a certain room for optimization, the present invention provides a continuous wave Ti:Sapphire laser power stabilization optimization system and method based on a three-mirror mode cleaner, which can greatly reduce the feedback photocurrent while further suppressing the frequency domain noise of the laser, greatly optimizing the suppression performance of the power stabilization system.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A continuous wave Ti:sapphire laser power stabilization optimization system based on a three-mirror mode cleaner, comprising an electro-optic modulator, a half-wave plate, a Glan-Taylor prism, an acousto-optic modulator, an aperture stop, a three-mirror mode cleaner, a photodetector, an analog regulation circuit, a reference voltage generation circuit, and a radio frequency driver;

[0008] The electro-optic modulator is used for adjusting the cavity length of the three-mirror mode cleaner;

[0009] The half-wave plate is used to adjust the polarization state of the incident laser;

[0010] The Glan-Taylor prism is used to further purify the polarization state of the incident laser;

[0011] The acousto-optic modulator is used to diffract the incident laser to generate 0th-order diffracted light and 1st-order diffracted light;

[0012] The aperture stop is used to intercept the 1st order diffracted light and pass the 0th order diffracted light;

[0013] The mode cleaner is used to feed back part of the laser for power feedback, thereby further reducing the intensity noise of the laser;

[0014] The electro-optic modulator, half-wave plate, Glan-Taylor prism, acousto-optic modulator, aperture stop, and three-mirror mode cleaner are sequentially passed through the incident laser;

[0015] The photoelectric detector, analog regulation circuit, reference voltage generation circuit and radio frequency driver together constitute a power feedback system, which generates feedback voltage for laser power feedback.

[0016] Furthermore, the mold cleaner is an optical cavity composed of three optical lenses with a cavity length of 1m, a fineness of 1000, a line width of 308kHz, and a laser transmittance of 66%. The three lenses are two plane mirrors for input and output and a concave mirror for laser reflection. The input mirror splits the 0th order diffraction light, the incident laser is reflected at the input mirror, and the light in the mold cleaner cavity is transmitted at the input mirror. The two beams of light are directly subtracted. Since the mold cleaner has a certain line width, high-frequency noise is retained, and the feedback photocurrent signal is suppressed, which has the effect of suppressing higher amplitude noise under low photocurrent signal, and outputs laser at the output mirror;

[0017] Furthermore, the analog regulation circuit includes a differential amplifier circuit, an analog PID regulation circuit, and a post-stage amplifier circuit, which are connected in sequence. The differential amplifier circuit is connected to a photodetector and a reference voltage generating circuit. The analog PID regulation circuit adopts analog parallel PID regulation, which is output to a radio frequency driver after post-stage amplification and filtering. The radio frequency driver is connected to an acousto-optic modulator for power modulation.

[0018] Furthermore, the reference voltage generating circuit includes a main control STM32 and a digital-to-analog conversion circuit, and the STM32 controls the digital-to-analog conversion circuit to generate a variable reference voltage with a voltage range of 0-5 V. The reference voltage generating circuit is compared with the voltage obtained by the photodetector to obtain a feedback error.

[0019] The present invention also discloses a method for optimizing the power stability of a continuous wave titanium sapphire laser based on a three-mirror mode cleaner, comprising the following steps:

[0020] Step 1: Adjust the output laser of the continuous wave Ti:sapphire laser to the normal working state. As the input, first adjust the polarization state to the vertical direction through the half-wave plate and Glan-Taylor prism and further purify it. Then input it into the acousto-optic modulator. Without applying the driving voltage, let the laser pass through the aperture diaphragm accurately to ensure that the laser is in the collimated state.

[0021] Step 2: Build a three-mirror mode cleaner. The input mirror and the output mirror are placed at 45°. The laser passes through the center of the input mirror and the output mirror. The distance between the input mirror and the output mirror is 20 cm. Adjust the position and angle of the reflector so that the reflected light of the output mirror and the transmitted light of the input mirror overlap in the cavity to form resonance. The distance between the reflector and the center of the input mirror and the output mirror is 40 cm. Stick piezoelectric ceramics on the back of the reflector and connect it to the electro-optic modulator through the PDH cavity lock system.

[0022] Step 3: Connect the photodetector to the subsequent analog control circuit, reference voltage generation circuit, and RF driver, and adjust the variable resistor to obtain the PID parameters that stabilize the detection voltage at the reference voltage, generate a driving voltage to the RF driver to control the acousto-optic modulator to control the diffraction efficiency and stabilize the laser power.

[0023] The beneficial effects of the present invention are:

[0024] The present invention reduces the photocurrent of the photodetector while maintaining the noise level through a mode cleaner, further suppresses the power noise of the titanium sapphire laser, and optimizes the performance of the titanium sapphire laser power stabilization system; generates a feedback voltage signal of the acousto-optic modulator through an analog circuit, wherein the analog PID regulation adopts a parallel PID method, which can achieve complete decoupling of the three parameters P / I / D. The present invention avoids the quantization error generated by the analog-to-digital conversion circuit and improves the accuracy and speed of the power feedback system. The mode cleaner can reduce the photocurrent of the detector while ensuring that the noise level remains unchanged. Compared with feedback after ordinary splitting, it can suppress more noise, especially high-frequency noise, at the same photocurrent level, and has broad application prospects in laser stabilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a structural schematic diagram of a continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the mold cleaner used in the present invention;

[0027] Figure 3 Schematic diagram for reducing power noise for the die cleaner;

[0028] Figure 4 This is a schematic diagram of the analog control and regulation circuit in the present invention.

[0029] Among them, the figure markings are: continuous wave titanium sapphire laser 1, electro-optic modulator 2, half-wave plate 3, Glan-Taylor prism 4, acousto-optic modulator 5, aperture diaphragm 6, input mirror 7, photodetector 8, analog control circuit 9, reference voltage generating circuit 10, RF driver 11, output mirror 12, reflector 13, piezoelectric ceramic 14. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0031] like Figure 1As shown, the power stabilization optimization system of a continuous wave titanium sapphire laser based on a three-mirror mode cleaner of the present invention comprises an electro-optic modulator 2, a half-wave plate 3, a Glan-Taylor prism 4, an acousto-optic modulator 5, an aperture stop 6, an input mirror 7, a photodetector 8, an analog control circuit 9, a reference voltage generation circuit 10, a radio frequency driver 11, an output mirror 12, a reflector 13, and a piezoelectric ceramic 14. The continuous wave titanium sapphire laser 1 generates incident laser light for a subsequent stabilization system, which is incident on the electro-optic modulator 2. The electro-optic modulator 2 is connected to the piezoelectric ceramic 14 through a PDH cavity locking method to control the voltage of the piezoelectric ceramic 14 for adjusting the cavity length of the three-mirror mode cleaner. After the incident laser light passes through the half-wave plate 3 and the Glan-Taylor prism 4, the polarization direction of the incident laser light becomes vertical and the polarization state is further purified, and then enters the acousto-optic modulator 5. The acousto-optic modulator 5 separates the incident laser light into 0th order diffraction light and 1st order diffraction light based on the Bragg diffraction principle. The aperture diaphragm 6 intercepts useless 1st-order diffraction light, and the 0th-order diffraction light enters the input mirror 7 through the central hole; the input mirror 7 is a plane mirror with a reflectivity of 99.6%, and the output mirror 12 is a plane mirror with a reflectivity of 99.6%. The input mirror 7, the output mirror 12, the reflector 13, and the piezoelectric ceramic 14 together constitute a three-mirror mode cleaner. After passing through the three-mirror mode cleaner, the laser is divided into two beams of light. The first beam of light reflected by the input mirror 7 is used as an in-ring beam for power feedback, and the second beam of light transmitted from the output mirror 12 is used for subsequent laser applications. The photodetector 8 detects the reflected light beam and converts the optical power into an electrical signal. The reference voltage generating circuit 10 uses SMT32 as the main control unit to control the high-precision digital-to-analog conversion circuit to generate a reference voltage. The analog control circuit 9 includes a differential amplifier circuit, an analog PID circuit, a post-amplifier and a filter circuit, and differentially amplifies the voltage signal of the photodetector 8 and the reference voltage. The analog PID circuit adopts a parallel PID structure, which can realize the decoupling adjustment of the P / I / D parameters. After the post-amplifier and filter, a feedback voltage signal is generated to the RF driver 11, which controls the acousto-optic driver to control the diffraction efficiency, thereby changing the power of the 0th order diffracted light and realizing stable power control.

[0032] The present invention stabilizes the laser power through the acousto-optic modulator 5, which is mainly composed of a piezoelectric transducer and an acousto-optic medium. When the transducer is driven by an externally generated electrical signal of a specific frequency, the transducer generates an ultrasonic signal of the same frequency, which is transmitted to the acousto-optic medium (transparent crystal), and a refractive index change is formed in the medium. When the laser beam passes through the acousto-optic medium (transparent crystal), an interaction occurs, and the propagation direction of the light is changed, that is, diffraction is generated. Changing the electrical signal can adjust the diffraction efficiency of the light and thus change the power of the laser.

[0033] like Figure 2The structure of the three-mirror mode cleaner is shown. In the laser wavelength range of 770-800nm, the input mirror 7 is a fused quartz lens with a laser reflectivity of 99.6% at an incident angle of 45°, with a high reflection film on the left and an anti-reflection film on the right; the output mirror 12 is a fused quartz lens with a laser reflectivity of 99.6% at an incident angle of 45°, with a high reflection film on the left and an anti-reflection film on the right; the reflector 13 is a fused quartz lens with a curvature radius of 1m and a laser reflectivity of 99.99% at an incident angle of 45°, with a frosted back and a high reflection film. The cavity length of the three-mirror mode cleaner is about 1m, the distance between the plane mirror is 20cm, the distance between the plane mirror and the concave mirror is 40cm, the fineness is 1000, the laser transmittance is 66%, and the line width is 308kHz.

[0034] like Figure 3 The figure shows the principle of the method of reducing power noise by the mode cleaner. The mode cleaner can be combined with the ordinary photoelectric feedback method to further reduce the power noise. This method can be called optical AC coupling (OAC). The OAC cavity in the figure represents the three-mirror mode cleaner used, and the PD (Photoelectric detector) is a photoelectric detector. The principle of the mode cleaner to reduce power noise is: the mode cleaner can reduce the photocurrent of the inner ring detector without reducing the sensitivity to power fluctuations. It is specifically manifested as a low-pass filter for transmitted light and a high-pass filter for reflected light. The transfer function can be used to study the changes in the laser after passing through the mode cleaner.

[0035] The input laser consists of the carrier laser and the power fluctuation of the laser. The power fluctuation can be approximately regarded as white noise, which constitutes the noise sideband. Within the line width of the resonant cavity, the carrier and the noise sideband are transmitted. Part of the field in the cavity leaks into the transmission field, and the other part enters the reflection field. The reflection field is composed of two laser beams at this time, which are the light directly reflected on the input mirror and the light leaked from the cavity into the reflection field. The combination of the two laser beams causes the carrier laser within the line width of the resonant cavity to be attenuated, and the noise sideband outside the line width maintains its original height. Therefore, the DC power detected on the detector at the reflection end is reduced, which can be equivalent to the detection of the full optical power incident on the resonator, and the actual optical power on the detector is significantly reduced. While maintaining the power noise level, the average power of the photodetector can be reduced. Of course, if the same average power of the photodetector is maintained, the noise sensitivity outside and inside the line width of the resonant cavity increases by about an order of magnitude, especially outside the line width.

[0036] Preferably, the reference voltage generating circuit 10 includes a main control STM32 and a digital-to-analog conversion circuit, and the STM32 controls the digital-to-analog conversion circuit to generate a variable reference voltage with a voltage range of 0-5V.

[0037] An important factor affecting the intensity of the reflected light leakage field is called the impedance factor. The magnitude of the impedance factor is called impedance matching. Impedance matching can be used to represent the degree of reduction of the incident optical carrier in the reflection field and is an important parameter of the mode cleaner. By calculating the impedance matching factor a at the resonant frequency:

[0038] ;

[0039] where, represents the voltage value of the reflected laser at the input mirror, represents the voltage value of the incident laser at the input mirror, R1 and R2 represent the reflectivities of the input mirror and the output mirror, and R L represents the internal cavity loss affected by the three cavity mirrors.

[0040] The effects of different impedance matching factors on the mode cleaner are different. According to the positive and negative of the impedance matching, the mode cleaner can be divided into three states: over-coupling, under-coupling, and impedance matching.

[0041] In the case of over-coupling, that is, -1 < a < 0, the carriers leaked by the mode cleaner are less than the directly reflected carriers. In the case of under-coupling, 0 < a < 1, the carriers leaked by the mode cleaner are greater than the directly reflected carriers. When the impedance is matched, a = 0.

[0042] To construct a high-finesse mode cleaner, it is required that the cavity mirrors have low loss. Since the impedance matching factor a has a strong correlation with the cavity mirror loss, the cavity mirror parameters must be precisely controlled. The impedance matching factor should be kept close to 0 to ensure that the carriers in the reflection field are greatly attenuated.

[0043] The mode cleaner needs to use the PDH cavity locking method to precisely match with the laser. The working principle of PDH cavity locking can be divided into the following steps: First, determine the mode cleaner as the reference cavity. When the laser frequency exactly matches the resonance frequency of the cavity, a resonance-enhanced signal will be generated in the cavity; then, apply a phase modulation signal to the laser. This modulation is usually carried out with a triangular wave or other waveforms with a frequency of dozens of kilohertz; place a photodetector at the reflection end of the resonant cavity. The detected reflected light and the phase modulation frequency of the laser are phase-demodulated through a mixer. The function of the mixer is to multiply the two input signals on both sides. The purpose is to select and eliminate the redundant cosine or sine terms in the frequency domain according to specific applications, analyze the phase change of the reflected light, combine the modulation signal, and then filter out all the high frequencies and direct currents through a low-pass filter. The specific phase difference information can be extracted. This phase difference is proportional to the frequency offset of the cavity; electro-optic modulator 2 is modulated, and finally, a feedback system is constructed using the phase difference information to transmit the feedback voltage to the piezoelectric ceramic 14 located on the resonant cavity, forming a closed loop. The cavity length control element adjusts based on this signal until the error approaches zero to maintain the resonance of the resonant cavity.

[0044] The mode cleaner is essentially an optical resonant cavity with specific impedance matching, and the relationship between the impedance matching and the transfer function of the mode cleaner can be studied through the transfer function.

[0045] The transfer function of the optical resonant cavity can be expressed as:

[0046] ;

[0047] in, represents the transfer function of the resonant cavity, f represents the frequency, i is the imaginary unit, The bandwidth of the mode cleaner is called the bandwidth, which represents the frequency value when the amplitude is attenuated to 3dB.

[0048] Transfer function of the mode cleaner from incident field to reflected field It can be expressed as follows:

[0049] ;

[0050] ;

[0051] Where g is called the optical AC coupling gain factor. Without considering mode matching, g is inversely proportional to the impedance matching factor a. At low frequencies, the transfer function gain is 1. / |g|, the transfer function gain increases, indicating that the sensitivity of the detection begins to increase. At high frequencies, the gain is close to |g|, and the phase depends on the sign of g. The power noise limit after passing through the resonant cavity can be expressed as:

[0052] ;

[0053] Where e represents the electron charge, represents the photocurrent, Represents the power noise of the spectrum.

[0054] like Figure 4 The figure shows the analog control adjustment process. The AIN signal is the voltage signal of laser detection, and DEMP_V is the reference voltage generated by the reference voltage circuit 10. After being isolated by the voltage follower, it is connected to the input end of the differential amplifier circuit. The output end is the error signal ERR. The parallel PID includes proportional, integral, and differential circuits from top to bottom. The differential circuit adopts RC differential, and the gain can be adjusted. After a post-amplification and filtering circuit, the PID_OUT signal is generated and output to the RF driver to modulate the acousto-optic modulator.

[0055] The adjustment process of the present invention comprises the following steps:

[0056] Step 1: Adjust the output laser of the continuous wave titanium sapphire laser 1 to the normal working state. As the input laser, it first passes through the half-wave plate 3 and the Glan-Taylor prism 4 to adjust the polarization state to the vertical direction and further purify it, and then input it into the acousto-optic modulator 5. Without applying a driving voltage, let the laser pass through the aperture diaphragm 6 accurately to ensure that the laser is in a collimated state.

[0057] Step 2: Build a three-mirror mode cleaner, with the input mirror 7 and the output mirror 12 placed at 45°. The laser passes through the center of the input mirror 7 and the output mirror 12. The distance between the input mirror 7 and the output mirror 12 is 20 cm. Adjust the position and angle of the reflector 13 so that the reflected light of the output mirror 12 and the transmitted light of the input mirror 7 overlap in the cavity to form resonance. The distance between the reflector 13 and the center of the input mirror 7 and the output mirror 12 is 40 cm. Paste the piezoelectric ceramic 14 on the back of the reflector 13 and connect it to the electro-optic modulator 2 through the PDH cavity lock system.

[0058] Step 3: Connect the photodetector 8 and the subsequent analog control circuit 9, reference voltage generating circuit 10, and RF driver 11, and obtain the PID parameters that stabilize the detection voltage at the reference voltage by adjusting the variable resistor, and generate a driving voltage to the RF driver to control the acousto-optic modulator to control the diffraction efficiency and stabilize the laser power.

[0059] Through the above three steps, automatic stabilization of laser power is achieved.

[0060] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is easy for the technical personnel in the field to understand that the above description is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A continuous wave Ti:sapphire laser power stabilization optimization system based on a three-mirror mode cleaner, characterized in that: Including electro-optic modulator, half-wave plate, Glan-Taylor prism, acousto-optic modulator, aperture diaphragm, three-mirror mode cleaner, photodetector, analog regulation circuit, reference voltage generation circuit, and RF driver; The electro-optic modulator is used for adjusting the cavity length of the three-mirror mode cleaner; The half-wave plate is used to adjust the polarization state of the incident laser; The Glan-Taylor prism is used to further purify the polarization state of the incident laser; The acousto-optic modulator is used to diffract the incident laser to generate 0th-order diffracted light and 1st-order diffracted light; The aperture stop is used to intercept the 1st order diffracted light and pass the 0th order diffracted light; The mode cleaner is used to feed back part of the laser for power feedback, thereby further reducing the power noise of the laser; The electro-optic modulator, half-wave plate, Glan-Taylor prism, acousto-optic modulator, aperture stop, and three-mirror mode cleaner are sequentially passed through the incident laser; The photoelectric detector, analog regulation circuit, reference voltage generation circuit and radio frequency driver together constitute a power feedback system, which generates feedback voltage for laser power feedback.

2. The continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner according to claim 1, characterized in that: The electro-optic modulator controls the piezoelectric ceramic voltage of the mode cleaner through the PDH cavity lock mode to adjust the cavity length of the three-mirror mode cleaner.

3. The continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner according to claim 1, characterized in that: The half-wave plate adjusts the polarization direction of the incident laser to a vertical direction.

4. The continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner according to claim 1, characterized in that: The acousto-optic modulator is connected to the radio frequency driver, and modulates the input laser according to the driving voltage of the radio frequency driver to control the relative power of the 0th order diffracted light and the 1st order diffracted light.

5. The continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner according to claim 1, characterized in that: The three-mirror mold cleaner is an optical cavity composed of three optical lenses, wherein the three lenses are two plane mirrors for input and output and one concave mirror for laser reflection, wherein the concave mirror is pasted with piezoelectric ceramics for cavity length locking, and within the laser wavelength range of 770-800nm, the input mirror is a fused quartz lens with a laser reflectivity of 99.6% at an incident angle of 45°, the output mirror is a fused quartz lens with a laser reflectivity of 99.6% at an incident angle of 45°, the reflector is a fused quartz lens with a curvature radius of 1m and a laser reflectivity of 99.99% at an incident angle of 45°, the cavity length of the mold cleaner is about 1m, the distance between the plane mirrors is 20cm, the distance between the plane mirror and the concave mirror is 40cm, the fineness is 1000, the laser transmittance is 66%, and the line width is 308kHz.

6. The continuous wave Ti:Sapphire laser power stabilization optimization system based on a three-mirror mode cleaner according to claim 1, characterized in that: The analog regulation circuit comprises a differential amplifier circuit, an analog PID regulation circuit, and a post-stage amplifier circuit which are connected in sequence. The differential amplifier circuit is connected to a photodetector and a reference voltage generating circuit. The analog PID regulation circuit adopts analog parallel PID regulation and is output to a radio frequency driver after post-stage amplification and filtering. The radio frequency driver is connected to an acousto-optic modulator.

7. The continuous wave Ti:Sapphire laser power stabilization optimization system based on three-mirror mode cleaner according to claim 1, characterized in that: The reference voltage generating circuit comprises a main control STM32 and a digital-to-analog conversion circuit. The STM32 controls the digital-to-analog conversion circuit to generate a variable reference voltage with a voltage range of 0-5V.

8. A method for optimizing the power stability of a continuous wave Ti:sapphire laser based on a three-mirror mode cleaner, characterized in that: The steps include: Step 1: Adjust the output laser of the continuous wave Ti:sapphire laser to the normal working state. As the input, first adjust the polarization state to the vertical direction through the half-wave plate and Glan-Taylor prism and further purify it. Then input it into the acousto-optic modulator. Without applying the driving voltage, let the laser pass through the aperture diaphragm accurately to ensure that the laser is in the collimated state. Step 2: Build a three-mirror mode cleaner. The input mirror and the output mirror are placed at 45°. The laser passes through the center of the input mirror and the output mirror. The distance between the input mirror and the output mirror is 20 cm. Adjust the position and angle of the reflector so that the reflected light of the output mirror and the transmitted light of the input mirror overlap in the cavity to form resonance. The distance between the reflector and the center of the input mirror and the output mirror is 40 cm. Stick piezoelectric ceramics on the back of the reflector and connect it to the electro-optic modulator through the PDH cavity lock system. Step 3: Connect the photodetector to the subsequent analog control circuit, reference voltage generation circuit, and RF driver, and adjust the variable resistor to obtain the PID parameters that stabilize the detection voltage at the reference voltage, generate a driving voltage to the RF driver to control the acousto-optic modulator to control the diffraction efficiency and stabilize the laser power.

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