Laser optical path thermal drift compensation device based on TEC and piezoelectric module

Abstract

The invention relates to the technical field of laser application, and discloses a laser optical path thermal drift compensation device based on a TEC and a piezoelectric module, and the device comprises a negative electrode, a semiconductor laser chip, a positive electrode, a thermoelectric refrigerating unit, a ceramic chip, a lens, a telescopic and deformable piezoelectric module, and a fixed pedestal. The system further comprises a control module, a light path detection sensor, a high-voltage driving circuit, a position sensor and a temperature sensor. A dual active compensation mechanism is adopted, and cooperative control is carried out on two thermal deformation sources of a laser and a lens at the same time: a thermoelectric refrigerating unit is responsible for stabilizing a laser source and fundamentally inhibiting temperature drift; the piezoelectric module dynamically compensates lens side deformation, the comprehensive stability performance of the system is remarkably improved, and the compensation effect is remarkably superior to that of a single means. The temperature control precision of the thermoelectric refrigerating unit can reach + / -0.1 DEG C, the piezoelectric module has nanoscale resolution and millisecond response speed, thermal deformation can be tracked and counteracted in real time, and long-term stability of an optical path is ensured.

Description

Technical Field

[0001] This invention relates to the field of laser application technology, specifically to a laser optical path thermal drift compensation device based on TEC and piezoelectric modules. Background Technology

[0002] Laser emitters (LDs) and their collimating lenses are core components of modern optical systems. However, during operation, thermal effects often arise due to their own heat generation or changes in ambient temperature. Specifically, the laser chip and its packaging materials expand and contract under temperature changes, causing a micrometer-level physical positional shift in the laser emission point. Simultaneously, the lens also undergoes thermal deformation, resulting in changes in the optical center height. These relative positional deviations alter the propagation path of the laser beam, leading to far-field spot drift or focal point shift, severely impacting the accuracy and stability of the optical system.

[0003] Currently, common solutions include passive thermal compensation and single temperature control.

[0004] Passive thermal compensation typically uses materials with low thermal expansion coefficients to manufacture supports and bases, attempting to offset deformation by having the structure "expand and fall together." However, this method is complex to design and cannot fully compensate for inconsistent deformation caused by material differences and asymmetrical heat sources.

[0005] A single temperature control method can control the temperature of a laser, thereby stabilizing its wavelength and output power, and suppressing the laser's own deformation to a certain extent. However, this method cannot solve the problem of thermal drift of the lens and mount caused by heating or changes in ambient temperature.

[0006] In summary, existing technologies still cannot efficiently and comprehensively solve the problem of optical path drift caused by thermal effects in laser optical systems. Therefore, we need to propose a laser optical path thermal drift compensation device based on TEC and piezoelectric modules, which can actively and in real time compensate for the deformation of the laser and lens caused by temperature changes, ensuring the long-term stability of the height and angle of the emitted laser optical path. Summary of the Invention

[0007] The purpose of this invention is to provide a laser optical path thermal drift compensation device based on TEC and piezoelectric modules, which can actively and in real time compensate for the deformation of the laser and lens caused by temperature changes, and ensure the long-term stability of the height and angle of the emitted laser optical path, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a laser optical path thermal drift compensation device based on TEC and a piezoelectric module, comprising: The negative electrode, the semiconductor laser chip, and the positive electrode are located on a common mounting substrate. The semiconductor laser chip serves as a laser emission source and is electrically connected to the positive electrode and the negative electrode, respectively. Thermoelectric coolers are used to absorb or generate heat to precisely stabilize the temperature of semiconductor laser chips at a preset first target temperature value. Ceramic sheets serve as insulation, heat conduction, and structural support; Lenses are used to collimate laser beams; A stretchable and deformable piezoelectric module is used to precisely adjust the vertical height position of the lens; The fixed base provides mechanical support and installation reference for the entire device; The cold end of the thermoelectric cooler is in contact with the bottom of the substrate, the hot end of the thermoelectric cooler is in contact with the ceramic plate, and the ceramic plate is located below the thermoelectric cooler. The ceramic plate and the piezoelectric module are both mounted on a fixed base, and the lens is mounted on a lens mount.

[0009] Preferably, it also includes a control module, which is electrically connected to the thermoelectric cooler and the piezoelectric module respectively. The control module drives the thermoelectric cooler to work through a built-in temperature control algorithm to keep the temperature of the semiconductor laser chip constant. The control module generates a high-voltage drive signal through a built-in displacement control algorithm and applies it to the piezoelectric module to dynamically adjust the lens height.

[0010] Preferably, it also includes an optical path detection sensor to collect the coordinate data of the laser spot on the detection surface in real time. The optical path detection sensor is electrically connected to the control module and the piezoelectric module respectively.

[0011] Preferably, the optical path detection sensor is a four-quadrant photodetector with an effective detection surface size of 4mm×4mm, a response wavelength range of 400-1100nm, a position resolution of 0.1μm, and a response time of ≤1μs.

[0012] Preferably, it also includes a high-voltage drive circuit for amplifying the low-voltage analog signal output by the control module and converting it into a high-precision high-voltage drive voltage required for the piezoelectric module to operate. The high-voltage drive circuit is electrically connected to both the control module and the piezoelectric module.

[0013] Preferably, it also includes a position sensor, which collects the actual height data of the lens in real time and feeds it back to the control module. The fixed end of the position sensor is installed on the side of the fixed base, and the detection end of the position sensor is connected to the side of the lens mount through an elastic clamp.

[0014] Preferably, the position sensor is a miniature grating ruler displacement sensor, the signal output terminal of the position sensor is connected to the communication interface of the control module through an RS485 interface, and the power supply terminal of the position sensor is connected to a 5V DC power supply provided by the control module.

[0015] Preferably, it also includes a temperature sensor for real-time acquisition of temperature data of the semiconductor laser chip. The temperature sensor is attached to the surface of the substrate by thermally conductive silicone and is adjacent to the cold end of the thermoelectric cooler. The leads of the temperature sensor are connected to the ADC acquisition channel of the control module through shielded wires. The temperature sensor is selected as a platinum resistance temperature sensor.

[0016] Preferably, the temperature control accuracy of the thermoelectric cooler is ±0.1℃, the piezoelectric module is a stacked piezoelectric ceramic actuator, the displacement resolution of the piezoelectric module is greater than 10 nanometers, and the maximum displacement stroke is greater than or equal to 30 micrometers.

[0017] Preferably, the ceramic sheet is an alumina ceramic sheet, and the fixing base is made of Invar alloy with a low coefficient of thermal expansion.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a dual active compensation mechanism, simultaneously coordinating the control of the two major thermal deformation sources: the thermoelectric cooler is responsible for stabilizing the laser source and fundamentally suppressing temperature drift; the piezoelectric module dynamically compensates for lens-side deformation, significantly improving the overall stability of the system, with a compensation effect significantly superior to a single method.

[0019] 2. This invention features high precision and fast response: the temperature control accuracy of the thermoelectric cooler can reach ±0.1°C, and the piezoelectric module has nanometer-level resolution and millisecond-level response speed, which can track and offset thermal deformation in real time, ensuring long-term stability of the optical path.

[0020] 3. This invention integrates an intelligent closed-loop feedback control system, which can automatically detect optical path deviations and achieve adaptive correction without manual intervention. It adapts to complex and ever-changing working environments, greatly improving the system's autonomy and reliability.

[0021] 4. The thermoelectric cooler and piezoelectric ceramic used in this invention are both miniaturized devices with compact structure and easy integration. They can be widely used in existing optical modules with low modification cost and strong applicability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is an exploded view of the negative electrode, semiconductor laser chip, positive electrode, thermoelectric cooler, and ceramic sheet of the present invention. Figure 3 This is a schematic diagram of the lens and piezoelectric module of the present invention.

[0023] In the diagram: 1. Negative electrode; 2. Semiconductor laser chip; 3. Positive electrode; 4. Thermoelectric cooler; 5. Ceramic plate; 6. Lens; 7. Piezoelectric module; 8. Fixing base. Detailed Implementation

[0024] 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.

[0025] Please see Figure 1-3 The present invention provides a technical solution: a laser optical path thermal drift compensation device based on TEC and piezoelectric module, including a negative electrode, a semiconductor laser chip, a positive electrode, a thermoelectric cooler, a ceramic sheet, a lens, a stretchable and deformable piezoelectric module, and a fixed base; it also includes a control module, an optical path detection sensor, a high voltage drive circuit, a position sensor, and a temperature sensor.

[0026] The negative electrode, the semiconductor laser chip, and the positive electrode are located on a common mounting substrate. The semiconductor laser chip serves as a laser emission source and is electrically connected to the positive electrode and the negative electrode, respectively. Thermoelectric coolers are used to absorb or generate heat to precisely stabilize the temperature of semiconductor laser chips at a preset first target temperature value. The thermoelectric cooler model is TEC1-12706. The specific implementation method is as follows: the temperature sensor collects the substrate temperature data of the semiconductor laser chip in real time and feeds the data back to the control module in real time. The control module has a built-in PID temperature control algorithm, which dynamically adjusts the direction and magnitude of the current applied to the thermoelectric cooler according to the deviation between the target temperature and the actual temperature. When the actual temperature is higher than the target temperature, the control module outputs a positive current to cool the cold end of the thermoelectric cooler; when the actual temperature is lower than the target temperature, it outputs a reverse current to switch the thermoelectric cooler to heating mode. Through this closed-loop control, precise temperature control of ±0.1℃ is achieved.

[0027] The ceramic sheet serves as insulation, thermal conductivity, and structural support; Lenses are used to collimate laser beams; The piezoelectric module is used to precisely adjust the vertical height of the lens; The specific adjustment process is as follows: The control module calculates the required compensation displacement of the lens based on the spot offset data fed back by the optical path detection sensor, and then converts it into the corresponding driving voltage value, which is output to the piezoelectric module through the high voltage driving circuit. The piezoelectric module generates expansion and contraction deformation under the action of voltage, which drives the lens mount to move in the vertical direction. At the same time, the position sensor collects the actual height data of the lens in real time and feeds it back to the control module. The control module compares the deviation between the actual displacement and the target displacement, and fine-tunes the driving voltage to form a closed-loop adjustment to ensure that the height adjustment accuracy reaches the nanometer level.

[0028] Specifically, the piezoelectric module is used to receive control signals and generate precise micro-displacements. The signal input terminal of the piezoelectric module is electrically connected to the high-voltage drive interface of the control module, receiving an adjustable high-voltage drive signal of 0-150V output from the control module. Based on the piezoelectric effect, the expansion and contraction of the piezoelectric ceramic in the piezoelectric module is linearly related to the input voltage. By adjusting the voltage amplitude of the drive signal, the control module can precisely control the expansion and contraction of the piezoelectric module, thereby achieving micro-displacement output with nanometer-level precision. The linear response range of the piezoelectric module's expansion and contraction with voltage is 0-120V, corresponding to an expansion and contraction range of 0-25μm. Within this range, the linearity error is ≤±0.5%. Above 120V, it enters the saturation region, and the linear response characteristics decay. Therefore, this application limits the drive voltage to operate within the 0-120V range to ensure the accuracy of displacement control.

[0029] The fixed base provides mechanical support and installation reference for the entire device; The cold end of the thermoelectric cooler is in contact with the bottom of the substrate, and the hot end of the thermoelectric cooler is in contact with the ceramic plate, thereby establishing an effective heat conduction path and realizing rapid temperature control of the laser chip. The ceramic plate is located below the thermoelectric cooler. Both the ceramic plate and the piezoelectric module are mounted on a fixed base, and the lens is mounted on a lens mount.

[0030] The control module supports closed-loop regulation using PID algorithm, which can simultaneously achieve temperature stabilization and optical path compensation, and has multi-parameter adaptive control capabilities.

[0031] The main control chip of the control module is the STM32H743VIT6. This chip is based on the ARM Cortex-M7 core, with a main frequency of up to 480MHz. It has powerful computing and processing capabilities and can meet the real-time requirements of multi-sensor data acquisition and complex algorithm calculation (PID-PWM composite control, three-dimensional mapping model calculation).

[0032] The control module is electrically connected to the thermoelectric cooler and the piezoelectric module respectively. The control module drives the thermoelectric cooler to work through a built-in temperature control algorithm to keep the temperature of the semiconductor laser chip constant. Meanwhile, the control module receives feedback signals from external optical path detection sensors. The control module generates a high-voltage drive signal through a built-in displacement control algorithm and applies it to the piezoelectric module to dynamically adjust the lens height, forming a closed-loop control system.

[0033] The optical path detection sensor collects the coordinate data of the laser spot on the detection surface in real time. The optical path detection sensor is electrically connected to the control module and the piezoelectric module respectively.

[0034] The feedback relationship between the optical path detection sensor and the piezoelectric module is as follows: the optical path detection sensor acquires the coordinate data of the laser spot on the detection surface in real time. When the spot position deviates from the preset reference position, it outputs the corresponding offset signals Δx and Δy. These signals are transmitted to the control module after analog-to-digital conversion. The displacement control algorithm adopts a PID-PWM composite control algorithm, where the PID parameter values ​​range from: proportional coefficient... Integral coefficient Differential coefficients The parameters can be adaptively adjusted according to the spot offset characteristics of the actual application scenario. The PWM frequency is set to 1kHz-10kHz. This frequency range can match the millisecond-level response speed of the piezoelectric module and avoid electromagnetic interference from high-frequency signals affecting the operation of other components. The displacement control algorithm dynamically corrects the duty cycle of the PWM signal by receiving the offset feedback from the four-quadrant photodetector and the displacement feedback from the piezoelectric module in real time. This ensures that the expansion and contraction of the piezoelectric module are precisely matched with the spot offset, realizes real-time compensation for optical path deviation, and ensures that the spot position is stable within the preset error range (≤±1μm), thus ensuring the long-term stability of the emitted laser optical path.

[0035] The optical path detection sensor is a four-quadrant photodetector of model PSD400-8. The effective detection surface size of the four-quadrant photodetector is 4mm×4mm, the response wavelength range is 400-1100nm, the position resolution is 0.1μm, the response time is ≤1μs, and it has an analog signal output interface that can be directly connected to the ADC acquisition channel of the control module.

[0036] The calculation logic of the optical path detection sensor is as follows: When thermal deformation of the lens causes optical path shift, the light spot will deviate from the detector's central reference position. The four-quadrant photodetector calculates the actual offset coordinates of the light spot by the difference in photocurrent signals between the four quadrants. , The specific calculation method is as follows: Let the photocurrents in the four quadrants be respectively... , , , Then the offset in the x direction (D is the quadrant spacing of the detector), offset in the y direction .

[0037] Combining the principles of geometric optics, the optical path offset angle (where f is the distance between the four-quadrant photodetector and the laser source, and is the focal length of the optical system), while the lens's compensation displacement... Must meet )( (where α is the focal length of the lens). At small angles, arctanα≈α, so we can obtain... The control module incorporates this calculation model, which will output the data from the four-quadrant photodetector. By substituting the signal into the formula, the precise compensation displacement required by the lens can be calculated in real time, ensuring that the light spot returns to the reference position.

[0038] The high-voltage drive circuit is used to amplify the low-voltage analog signal output by the control module and convert it into the high-precision high-voltage drive voltage required for the piezoelectric module to work. At the same time, it realizes voltage signal stabilization, filtering and power amplification, ensuring the linear response and control accuracy of the piezoelectric module's expansion and contraction, and avoiding displacement errors caused by voltage fluctuations. The high-voltage drive circuit is electrically connected to both the control module and the piezoelectric module.

[0039] The main components of a high-voltage drive circuit include a boost unit, an amplification unit (operational amplifier, power amplifier), a filtering unit, and a protection unit.

[0040] Boost unit: Uses MAX1771 DC-DC boost controller, with an input voltage of 12V and adjustable output from 0-150V; Operational amplifier: A high-voltage operational amplifier of model OPA445 is selected to preamplify the low-voltage signal of the control module to ensure signal driving capability; Power amplification components: The N-channel MOSFET of model IRF840 is used as a power switching device to amplify the power of the boosted voltage signal and meet the drive current requirements of the piezoelectric module (maximum drive current ≤500mA). Filtering unit: includes a 10μF electrolytic capacitor and a 0.1μF ceramic capacitor, forming a π-type filter circuit to filter out high-frequency noise in high-voltage signals; Protection unit: Includes a 120V Zener diode and a 2A fast-acting fuse, which respectively provide overvoltage protection and overcurrent protection to prevent the piezoelectric module from being damaged due to excessive voltage or current.

[0041] The main control chip of the drive voltage output process control module outputs a PWM signal corresponding to the compensation displacement. This signal is input to the OPA445 operational amplifier for amplification and then transmitted to the feedback input terminal of the MAX1771 boost controller. The MAX1771 adjusts the duty cycle of its internal switching transistor according to the amplitude of the input signal to boost the 12V input voltage to the target voltage value. The boosted high-voltage signal is filtered for noise by a π-type filter circuit and then amplified by the IRF840 MOSFET. Finally, a stable 0-120V drive voltage is output to the signal input terminal of the piezoelectric module to drive the piezoelectric module to achieve precise extension and retraction.

[0042] The position sensor collects the actual height data of the lens in real time and feeds it back to the control module. The fixed end of the position sensor is installed on the side of the fixed base, and the detection end (grating reading head) of the position sensor is connected to the side of the lens mount through an elastic clamp to ensure that the detection end moves synchronously with the lens.

[0043] The position sensor is a miniature grating ruler displacement sensor of model LK-G80. The signal output terminal of the position sensor is connected to the communication interface of the control module through an RS485 interface, and the power supply terminal of the position sensor is connected to a 5V DC power supply provided by the control module.

[0044] Height data acquisition principle: The miniature grating ruler displacement sensor consists of a scale grating and a reading head. The scale grating has equally spaced grating stripes. During operation, light emitted from the LED light source inside the reading head illuminates the scale grating and forms moiré fringes after diffraction. When the lens moves the reading head vertically, the position of the moiré fringes changes periodically. The photodetector inside the reading head converts this optical signal into an electrical pulse signal. The control module counts the number of pulse signals and, combined with the grating pitch and subdivision factor, calculates the actual height displacement of the lens (displacement = number of pulses × grating pitch / subdivision factor), achieving real-time height data acquisition at a frequency of 1kHz to ensure the real-time performance of closed-loop adjustment.

[0045] The temperature sensor is used to collect temperature data of the semiconductor laser chip in real time. The temperature sensor is attached to the surface of the substrate with thermally conductive silicone and is adjacent to the cold end of the thermoelectric cooler to ensure tight contact with the chip substrate and improve the accuracy of temperature acquisition. The lead of the temperature sensor is connected to the ADC acquisition channel of the control module through a shielded wire. The temperature sensor is a PT1000 platinum resistance temperature sensor.

[0046] The temperature control accuracy of the thermoelectric cooler is within ±0.1℃, effectively suppressing thermal drift. The piezoelectric module uses a stacked piezoelectric ceramic actuator, and the displacement resolution of the piezoelectric module is greater than 10 nanometers, with a maximum displacement stroke greater than or equal to 30 micrometers.

[0047] The ceramic sheet is made of alumina ceramic, which has good insulation, thermal conductivity and mechanical strength. The fixing base is made of Invar alloy with low thermal expansion coefficient to passively reduce the impact of ambient temperature changes on the system's basic structure.

[0048] There is a specific material synergy between the ceramic sheet, the mounting base, and the piezoelectric module. A comparison of their specific thermal expansion coefficients is as follows: Invar alloy thermal expansion coefficient... The coefficient of thermal expansion of alumina ceramics The coefficient of thermal expansion of piezoelectric ceramics The difference in thermal expansion coefficients between the alumina ceramic sheet and the ceramic substrate of the piezoelectric module. This can minimize the thermal stress deformation at the interface between the two when the temperature changes, thus avoiding affecting the installation accuracy of the piezoelectric module; The Invar alloy used in the fixed base has a much lower coefficient of thermal expansion than the previous two, which can provide a stable mounting reference for the piezoelectric module and ceramic sheet, effectively suppressing the impact of environmental temperature changes on the overall structure. At the same time, the high thermal conductivity of the alumina ceramic sheet can quickly conduct the heat generated by the thermoelectric cooling module to the Invar alloy base, and then dissipate it into the environment through the base, avoiding heat accumulation that affects the working stability of each component. The material properties of the three are matched with each other to jointly ensure the structural stability and compensation accuracy of the system.

[0049] During operation, the control module first drives the thermoelectric cooling module to quickly stabilize the temperature of the semiconductor laser chip at the set value, fundamentally suppressing the thermal drift of the laser source itself. Subsequently, the system monitors the position of the output beam. When it detects an optical path deviation caused by lens thermal deformation, the control module immediately calculates the compensation amount and drives the piezoelectric module to generate a corresponding precise displacement, raising or lowering the lens to compensate for the optical path deviation and return the beam position to the initial set position. Through the coordinated operation of the temperature control of the thermoelectric cooling module 4 and the displacement compensation of the piezoelectric module, high-precision, active compensation for thermal drift of the laser optical path is achieved. The control module's coordinated timing control method for the thermoelectric cooler and piezoelectric module is as follows: During system startup, the control module first drives the TEC into a rapid temperature control mode, setting the heating / cooling rate to 5℃ / s, while the temperature sensor simultaneously collects the temperature data of the semiconductor laser chip.

[0050] The specific triggering conditions and response delays for the timing switching threshold are as follows: First, the trigger condition for the thermoelectric cooler to switch from rapid temperature control mode to constant temperature regulation mode is "the error between the actual chip temperature and the target temperature is ≤0.5℃", the response delay is ≤10ms, and after switching, the PID parameters are adjusted to a low gain (Kp=0.5, Ki=0.01, Kd=0.1) and slow response state to reduce temperature fluctuations. Second, the trigger condition for the piezoelectric module to switch from the preheating program to the dynamic compensation mode is "0.2s before TEC enters the constant temperature regulation mode", with a response delay of ≤3ms. The preheating program mainly completes the zero-point calibration of the high-voltage drive circuit. Third, the trigger condition for emergency switching due to sudden temperature changes is "the chip temperature change is ≥0.3℃ within 1 second" and the response delay is ≤5ms. At this time, the control module temporarily enhances the adjustment gain of TEC (Kp=2.0, Ki=0.1, Kd=0.5), and the piezoelectric module performs predictive compensation based on the three-dimensional mapping model.

[0051] In addition, the control module also established a three-dimensional mapping model of temperature-displacement-spot offset. The polynomial coefficients a, b, and c of the model were obtained by least squares calibration. The specific calibration process is as follows: construct an experimental dataset of ambient temperature-lens thermal deformation displacement-spot offset. The ambient temperature range is -20℃ to 60℃. A sampling point is set every 5℃. At each temperature point, 10 different thermal deformation displacements and corresponding spot offsets are obtained by changing the initial height of the lens. The total size of the dataset is 16 temperature points × 10 data sets = 160 valid samples. Constructing the objective function based on the least squares method The objective function J is minimized through iterative calculation, and the optimal coefficients a, b, and c are obtained. After calibration, the model prediction error is ≤ ±0.2μm. During operation, the control module first calculates the data collected by the temperature sensor. Perform feedforward compensation, and then combine it with the beam offset. Feedback correction is performed to form a feedforward-feedback composite control, which improves the compensation response speed by more than 30% and reduces the compensation error to the nanometer level.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules, characterized in that, include: The negative electrode, the semiconductor laser chip, and the positive electrode are located on a common mounting substrate. The semiconductor laser chip serves as a laser emission source and is electrically connected to the positive electrode and the negative electrode, respectively. Thermoelectric coolers are used to absorb or generate heat to precisely stabilize the temperature of semiconductor laser chips at a preset first target temperature value. Ceramic sheets serve as insulation, heat conduction, and structural support; Lenses are used to collimate laser beams; A stretchable and deformable piezoelectric module is used to precisely adjust the vertical height position of the lens; The fixed base provides mechanical support and installation reference for the entire device; The cold end of the thermoelectric cooler is in contact with the bottom of the substrate, the hot end of the thermoelectric cooler is in contact with the ceramic plate, and the ceramic plate is located below the thermoelectric cooler. The ceramic plate and the piezoelectric module are both mounted on a fixed base, and the lens is mounted on a lens mount.

2. The laser optical path thermal drift compensation device based on TEC and piezoelectric module according to claim 1, characterized in that: It also includes a control module, which is electrically connected to the thermoelectric cooler and the piezoelectric module respectively. The control module drives the thermoelectric cooler to work through a built-in temperature control algorithm to keep the temperature of the semiconductor laser chip constant. The control module generates a high-voltage drive signal through a built-in displacement control algorithm and applies it to the piezoelectric module to dynamically adjust the lens height.

3. The laser optical path thermal drift compensation device based on TEC and piezoelectric module according to claim 2, characterized in that: It also includes an optical path detection sensor, which collects the coordinate data of the laser spot on the detection surface in real time. The optical path detection sensor is electrically connected to the control module and the piezoelectric module respectively.

4. The laser optical path thermal drift compensation device based on TEC and piezoelectric module according to claim 3, characterized in that: The optical path detection sensor is a four-quadrant photodetector with an effective detection surface size of 4mm×4mm, a response wavelength range of 400-1100nm, a position resolution of 0.1μm, and a response time of ≤1μs.

5. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 1, characterized in that: It also includes a high-voltage drive circuit, which amplifies the low-voltage analog signal output by the control module and converts it into a high-precision high-voltage drive voltage required for the piezoelectric module to operate. The high-voltage drive circuit is electrically connected to both the control module and the piezoelectric module.

6. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 5, characterized in that: It also includes a position sensor, which collects the actual height data of the lens in real time and feeds it back to the control module. The fixed end of the position sensor is installed on the side of the fixed base, and the detection end of the position sensor is connected to the side of the lens mount through an elastic clamp.

7. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 6, characterized in that: The position sensor is a miniature optical grating ruler displacement sensor. The signal output terminal of the position sensor is connected to the communication interface of the control module through an RS485 interface, and the power supply terminal of the position sensor is connected to a 5V DC power supply provided by the control module.

8. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 7, characterized in that: It also includes a temperature sensor for real-time acquisition of temperature data of the semiconductor laser chip. The temperature sensor is attached to the surface of the substrate with thermally conductive silicone and is adjacent to the cold end of the thermoelectric cooler. The leads of the temperature sensor are connected to the ADC acquisition channel of the control module through shielded wires. The temperature sensor is a platinum resistance temperature sensor.

9. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 1, characterized in that: The temperature control accuracy of the thermoelectric cooler is ±0.1℃. The piezoelectric module uses a stacked piezoelectric ceramic actuator. The displacement resolution of the piezoelectric module is greater than 10 nanometers, and the maximum displacement stroke is greater than or equal to 30 micrometers.

10. A laser optical path thermal drift compensation device based on TEC and piezoelectric modules according to claim 1, characterized in that: The ceramic sheet is made of alumina ceramic, and the fixing base is made of Invar alloy with a low coefficient of thermal expansion.

Images