Self-adaptive laser high-power stable device

Abstract

The utility model relates to a self-adaptive laser high-power stable device, which is characterized by comprising an optical platform, a laser is horizontally fixed on the leftmost side of the top end of the optical platform, and a rotary displacement table, a polarization beam splitter prism, a sampling mirror and a photoelectric detector PD are sequentially and vertically fixed on the rear side of the laser from front to back. A single-chip microcomputer is arranged on the rear side of the photoelectric detector PD, a half-wave plate is embedded in the rotary displacement table, a reflecting mirror is vertically fixed to the right side of the sampling mirror, and a power meter is arranged on the rear side of the reflecting mirror. The device can realize self-adaptive adjustment of the laser power, and meets the requirements of different application scenes on the laser power; and meanwhile, all used optical devices are plated with high-transmittance films with corresponding laser wavelengths, so that the influence of a high-power laser heat effect is avoided, and the stability and the precision of laser power adjustment can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high-power lasers, in particular to a device for adaptively stabilizing high-power lasers. Background Art

[0002] With the continuous development of laser technology, laser devices are being used more and more widely in various fields. Stable laser regulation is a very important technology in the laser application process. However, due to the high power output of high-power lasers, a very large heating effect will be generated, which will cause significant thermal expansion of related devices, thus affecting the regulation effect and the stability of laser power. For example, in a laser regulation device based on an acousto-optic modulator, the acousto-optic modulator in the device will be affected by the thermal effect and the temperature will rise, which will affect its modulation effect and the output laser quality, thereby affecting the stability and accuracy of high-power lasers. Utility Model Content

[0003] 1. Technical issues to be resolved

[0004] In view of the limitations of existing laser stabilization devices, the purpose of the utility model is to provide an adaptive laser high-power stabilization device that can realize adaptive adjustment of laser power to meet the laser power requirements of different application scenarios; at the same time, it is not affected by the thermal effect of high-power lasers, thereby improving the stability and accuracy of laser power adjustment.

[0005] (II) Technical solution

[0006] To achieve the above purpose, the utility model provides the following technical solutions: an adaptive laser high-power stabilization device, characterized in that it includes: an optical platform, a laser is horizontally fixed on the leftmost side of the top of the optical platform, a rotating displacement stage, a polarization beam splitter prism, a sampling mirror and a photodetector PD are vertically fixed to the rear side of the laser from front to back, a single-chip microcomputer is arranged on the rear side of the photodetector PD, a half-wave plate is embedded inside the rotating displacement stage, a reflector is vertically fixed on the right side of the sampling mirror, and a power meter is arranged on the rear side of the reflector; the bottom ends of the laser, the rotating displacement stage, the polarization beam splitter prism, the sampling mirror, the photodetector PD, the reflector, the power meter and the single-chip microcomputer are all fixedly connected to the top of the optical platform. The optical platform is the foundation of the entire device, and all components are fixed on the top of the optical platform; the laser is the source of light, which can release high-power laser. After passing through the center of the half-wave plate embedded in the rotating stage, the laser will pass through the center of the polarization beam splitter prism. After being sampled by the sampling mirror, the transmitted light of the polarization beam splitter prism will realize the transmission sampling of a small part of the laser power and then be input to the center of the photodetector PD. The photodetector PD will monitor and sample the laser beam after the transmission sampling, and transmit the signal to the single-chip microcomputer for subsequent processing; the single-chip microcomputer mainly receives the signal from the photodetector PD, processes the photoelectric signal, and then controls the rotating stage to adjust the angle of the half-wave plate, so as to adjust the laser power adaptively and maintain the stable power of the laser output; at the same time, a reflector is set behind the sampling mirror, and most of the reflected light in the sampling mirror will be reflected to the center of the probe of the power meter through the reflector, so that the power meter can monitor the size and stability of the laser power in real time.

[0007] Preferably, the single-chip microcomputer includes an analog-to-digital conversion port AD and a serial port USB. The photodetector PD and the rotary translation stage are connected to the single-chip microcomputer through the analog-to-digital conversion port AD and the serial port USB respectively. The single-chip microcomputer serves as the control center of the entire system and is responsible for signal conversion, data processing and execution control. On the one hand, it is connected to the photodetector PD through the analog-to-digital conversion port AD, that is, the photodetector PD inputs the detected laser signal into the single-chip microcomputer through the analog-to-digital conversion port AD. The analog-to-digital conversion port AD has a signal conversion function. Since the photodetector PD outputs an analog signal indicating the light intensity, and the single-chip microcomputer needs a digital signal for processing, the photodetector PD and the single-chip microcomputer must be connected through the analog-to-digital conversion port AD so that the analog signal of the photodetector PD can be converted into a digital signal and enter the single-chip microcomputer; after the single-chip microcomputer processes the digital signal, the laser power needs to be adjusted, and the adjustment is achieved by controlling the rotation angle of the rotary stage equipped with a half-wave plate. When the half-wave plate is rotated to different angles, the laser power passing through the polarization beam splitter prism will be different, which can achieve adaptive adjustment of the laser power; and the rotation of the rotary stage is mainly electronically controlled by the single-chip microcomputer, that is, digital communication is achieved between the single-chip microcomputer and the rotary stage through the serial port USB, and the control signal and feedback data of the rotary stage are transmitted through the serial port USB, so that the single-chip microcomputer can accurately control the rotation angle of the half-wave plate.

[0008] Preferably, the single-chip microcomputer realizes the control of the rotation angle of the rotary translation stage through the PID algorithm. The single-chip microcomputer calculates a control signal according to the PID algorithm, and the signal is used to adjust the angle of the rotary translation stage. The control signal is sent to the drive system of the rotary translation stage through the serial port USB to adjust the angle of the half wave plate and the laser power. The adjusted laser power will be detected again by the photodetector PD and fed back to the single-chip microcomputer to form a closed-loop control system. The single-chip microcomputer continuously collects new power data, updates the error value, and repeats the PID calculation and adjustment process to ensure that the laser power remains at the preset power value.

[0009] Specifically, the PID algorithm consists of three main parts: (1) Proportional (P); (2) Integral (I); (3) Differential (D). Proportional (P) means that the control output is proportional to the error. The error refers to the difference between the current detection value and the target value, that is, the difference between the photoelectric signal detected by the photodetector PD and the reference signal set by the microcontroller. The proportional coefficient Kp determines the controller's response to the current error; Integral (I) means that the control output is proportional to the accumulated value of the error. It eliminates the steady-state error of the system by accumulating the error. The integral coefficient Ki determines the controller's response to the accumulated error; Differential (D) means that the control output is proportional to the error change rate. It reduces the error fluctuation by predicting the error change trend. The differential coefficient Kd determines the controller's response to the error change rate.

[0010] PID control process:

[0011] (1) Proportional control (P): Directly adjust the angle of the rotation stage according to the current error. The larger the error, the greater the adjustment.

[0012] (2) Integral control (I): Adjust according to the accumulated value of the error to eliminate the long-term accumulated error and stabilize the laser power.

[0013] (3) Differential control (D): Adjust according to the changing trend of the error to prevent and reduce the oscillation and fluctuation of the error.

[0014] Preferably, the light beam output by the laser passes through the center positions of the half wave plate, polarization beam splitter prism and sampling mirror in sequence and reaches the center position of the photodetector PD, and the reflected light beam of the sampling mirror passes through the center position of the reflector and reaches the center position of the power meter.

[0015] Preferably, the rotary stage is coaxial and concentric with the half wave plate, so that each angle adjustment of the rotary stage can accurately change the polarization direction of the laser beam after passing through the half wave plate, thereby realizing the adjustment of the transmission and reflected laser power distribution of the laser beam after passing through the polarization beam splitter prism. The transmitted light of the polarization beam splitter prism passes through the sampling mirror to realize the transmission sampling of a small part of the laser power, which is input into the photodetector PD. The photodetector PD feeds back the detected photoelectric signal to the single-chip microcomputer, and the single-chip microcomputer adjusts the rotary stage according to the feedback signal given by the PID algorithm to ensure the stability of the laser power transmitted by the polarization beam splitter prism.

[0016] It should be further explained that the sampling rate of the sampling mirror here is pre-set and fixed during the design and manufacturing process. Here, our sampling mirror adopts transmission sampling, that is, most of the light is reflected after passing through the sampling mirror, and only a small part of the light is transmitted and sampled. For example, if the sampling rate of the sampling mirror is 1‰ (one thousandth), it means that when a 1 watt (W) beam is incident on the sampling mirror, 99.9% of the light (that is, 0.999 watts) is reflected and 0.1% of the light (that is, 0.001 watts or 1 milliwatt) is transmitted. The sampling mirror samples the transmitted light and inputs it into the photodetector PD, so that the single-chip microcomputer can adjust the angle of the half-wave plate in real time according to the received photoelectric signal, and then can accurately control the polarization direction of the laser beam after passing through the half-wave plate, thereby realizing the adjustment of the power distribution of the reflected beam and the transmitted beam of the polarization beam splitter prism. Changes in the transmitted light power of the polarization beam splitter prism will directly lead to changes in the transmitted light power of the sampling mirror, which will then be detected by the photodetector PD and input into the microcontroller for analysis and processing, thereby achieving stable control and adjustment of the transmitted light of the sampling mirror, and further achieving stable control and adjustment of the high-power laser.

[0017] Furthermore, both the half wave plate and the polarization beam splitter prism are made of high-quality optical crystal materials with low absorption and high laser damage threshold; and the optical devices used are coated with high-transmittance films of the corresponding laser wavelength to ensure that most of the laser beam passes through the wave plate and prism without unnecessary reflection and loss; making the beam transmission more efficient, reducing the energy loss due to reflection, and improving the overall performance and stability of the system; at the same time, thermal management is taken into consideration in the design of the polarization beam splitter prism, and materials and structures with good thermal stability are used.

[0018] (III) Beneficial effects

[0019] (1) By real-time monitoring and precise control of the angle of the half-wave plate, adaptive adjustment can be made as needed to meet the laser power requirements of different application scenarios, while ensuring stable output of laser power, thereby ensuring the stability and accuracy of laser power.

[0020] (2) High-power laser beam guidance through half-wave plates and polarization beam splitters can effectively reduce the impact of thermal effects and improve the stability and accuracy of laser power adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0022] Figure 2 It is a connection diagram of the single chip microcomputer in the utility model.

[0023] In the figure: 1-optical platform 2-laser 3-rotation translation stage 30-half wave plate 4-polarization beam splitter prism 5-sampling mirror 6-photodetector PD 7-reflector 8-power meter 9-single chip microcomputer 91-analog-to-digital conversion port AD 92-serial port USB. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] Embodiment 1: Figure 1As shown, the first specific embodiment of the utility model provides an adaptive laser high-power stabilization device, comprising: an optical platform 1, a laser 2 is horizontally fixed on the leftmost side of the top of the optical platform 1, a rotating displacement stage 3, a polarization beam splitter prism 4, a sampling mirror 5 and a photodetector PD6 are vertically fixed on the rear side of the laser 2 from front to back, a single-chip microcomputer 9 is arranged on the rear side of the photodetector PD6, a half-wave plate 30 is embedded inside the rotating displacement stage 3, a reflector 7 is vertically fixed on the right side of the sampling mirror 5, and a power meter 8 is arranged on the rear side of the reflector 7;. The bottom ends of the laser 2, the rotating displacement stage 3, the polarization beam splitter prism 4, the sampling mirror 5, the photodetector PD6, the reflector 7, the power meter 8 and the single-chip microcomputer 9 are all fixedly connected to the top of the optical platform 1. The laser 2 is horizontally mounted on the optical platform 1; the half-wave plate 30 is embedded on the rotating displacement stage 3; the polarization beam splitter prism 4, the sampling mirror 5, the photodetector PD6, and the reflector 7 are vertically mounted on the optical platform, forming the basic framework of the device. The reflected light from the reflector 7 enters the power meter 8, which can monitor the laser power in real time; the photodetector PD6 detects the photoelectric signal and inputs it into the single-chip microcomputer 9, which processes the signal through the PID algorithm and controls the rotation of the half-wave plate on the rotary translation stage. The laser power passing through the polarization beam splitter prism will be different at different angles, thereby realizing adaptive adjustment of the high-power laser device to meet the laser power requirements of different application scenarios.

[0026] The single-chip microcomputer 9 includes an analog-to-digital conversion port AD91 and a serial port USB92. The photodetector PD6 and the rotary displacement stage 3 are connected to the single-chip microcomputer 9 through the analog-to-digital conversion port AD91 and the serial port USB92 respectively. The photodetector PD6 converts the detected laser power signal into an analog signal, and the analog-to-digital conversion port AD91 can convert the analog signal detected by the photodetector PD6 into a high-resolution digital signal, which is convenient for the single-chip microcomputer 9 to accurately process and analyze; at the same time, the analog-to-digital conversion port AD91 can realize real-time signal acquisition, ensure that the laser power change is quickly captured, and improve the system response speed and control accuracy. The serial port USB92 establishes a connection with the rotary displacement stage 3 to achieve fast and reliable data transmission and control signal sending. The USB interface has a high data transmission rate and can update the angle of the rotary displacement stage in time to ensure the dynamic adjustment ability of the system; the single-chip microcomputer acts as a central control unit, uniformly manages data acquisition and equipment control, reduces the complexity of wiring inside the system, and improves the reliability and neatness of the system; at the same time, the analog-to-digital conversion port AD91 and the serial port USB92 work independently, avoiding signal interference, and improving the reliability and accuracy of data acquisition and control signal transmission.

[0027] In other words, the single chip microcomputer establishes connections with the photodetector and the rotary translation stage respectively through the analog-to-digital conversion port AD and the serial port USB. This design not only improves the performance and reliability of the system, but also improves the flexibility and maintainability of the system, and adapts to complex and changing application requirements.

[0028] The single chip computer 9 controls the rotation angle of the rotary displacement stage 3 through the PID algorithm. The rotation of the rotary displacement stage is controlled by the PID algorithm, and then the angle of the half wave plate is changed, so that the precise control of the laser power can be achieved. At the same time, the dynamic response capability is strong. The PID algorithm can process the feedback signal in real time, respond quickly to the change of laser power, adjust the angle of the rotary displacement stage, and realize the dynamic regulation of the laser power. The PID control can adjust the system faster and more accurately by comprehensively considering the current error, historical error and error change rate, thereby reducing the response time and system lag. The PID algorithm effectively adjusts the movement of the rotary displacement stage to avoid excessive adjustment range, thereby reducing system oscillation and overshoot, and maintaining the stability of the laser output.

[0029] By using the PID algorithm to control the rotation angle of the rotary translation stage, the accuracy, response speed and stability of the laser power stabilization device can be significantly improved, and the degree of automation and work efficiency of the system can be improved. The wide adaptability and easy implementation of PID control make it an ideal choice for optimizing laser power control, providing a strong guarantee for the long-term stable operation of the system.

[0030] The light beam output by the laser 2 passes through the center positions of the half wave plate 30, the polarization beam splitter prism 4 and the sampling mirror 5 in sequence and then reaches the center position of the photodetector PD6; the reflected light beam of the sampling mirror 5 passes through the center position of the reflector 7 and then reaches the center position of the power meter 8; when the light beam passes through the center position of the optical element, the geometric and material properties of the optical element have the least effect on the light beam, reducing the distortion and the change of the spot shape, and maintaining the quality of the light beam. The center position is usually the most symmetrical position of the optical element. The light beam passing through the center position can ensure the symmetry of the optical path and avoid the divergence or unevenness of the light beam caused by eccentricity. The light beam is concentrated at the center position of the detector and the power meter, ensuring that the photodetector and the power meter are evenly irradiated, and improving the accuracy and consistency of the measurement.

[0031] At the same time, the light beam is concentrated at the center of the power meter, ensuring that the light energy measured by the power meter is accurate and reflects the actual laser output power. In addition, the light beam passes through the central area of ​​the optical element, and the light energy is evenly distributed, which reduces the thermal effect caused by local high temperature, is conducive to the uniform heat dissipation of the optical element, reduces the risk of thermal damage to the optical element due to heat accumulation, and improves the long-term stability of the system.

[0032] The rotation stage 3 is coaxial and concentric with the half wave plate 30. The coaxial and concentric design ensures that the rotation axes of the rotation stage and the half wave plate are on the same straight line, making the optical path adjustment more intuitive and simple; at the same time, it ensures that the movement axes of the rotation stage and the half wave plate are consistent, reducing the possibility of mechanical vibration and looseness, which is conducive to maintaining the stability of the optical path.

[0033] In addition, keeping the rotation axis coaxial and concentric can reduce the optical path drift and wave plate position offset caused by mechanical factors, thereby improving the long-term stability of the optical system.

[0034] Working principle: When working, turn on the laser 2, and the laser emitted by the laser 2 passes through the half wave plate 30 of the rotating stage 3, and then passes through the polarization beam splitter prism 4. The light passing through the polarization beam splitter prism 4 will enter the sampling mirror 5 and be sampled by the sampling mirror 5. Most of the reflected light beams of the sampling mirror 5 will enter the power meter 8 after passing through the reflector 7. The power meter 8 detects and feeds back the real-time power of the laser; at the same time, a small part of the transmitted light of the sampling mirror 5 enters the photodetector PD6. The photodetector PD6 detects the photoelectric signal and inputs it to the single-chip microcomputer 9 through the analog-to-digital conversion port AD91. The single-chip microcomputer 9 calculates the actual laser power through the PID algorithm according to the detected signal and compares it with the set power value. If a deviation is detected, the single-chip microcomputer 9 will output a control instruction through the serial port USB92 to control the rotation of the rotating stage to change the angle of the half wave plate 30, thereby adjusting the ratio of the transmitted light and the reflected light, and finally achieving the purpose of stabilizing the laser output power. In this process, the power meter 8 will detect the power of the laser beam in real time and feed back to verify whether the adjusted laser output power reaches the expected value, so as to adjust the control strategy in time.

[0035] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adaptive laser high power stabilization device, characterized in that: include: An optical platform (1) is provided, wherein a laser (2) is horizontally fixed on the leftmost side of the top of the optical platform (1), a rotational displacement stage (3), a polarization beam splitter prism (4), a sampling mirror (5) and a photodetector PD (6) are vertically fixed to the rear side of the laser (2) in order from front to back, a single-chip microcomputer (9) is arranged on the rear side of the photodetector PD (6), a half-wave plate (30) is embedded inside the rotational displacement stage (3), a reflector (7) is vertically fixed to the right side of the sampling mirror (5), and a power meter (8) is arranged on the rear side of the reflector (7).

2. According to the adaptive laser high-power stabilization device described in claim 1, the bottom ends of the laser (2), the rotation stage (3), the polarization beam splitter prism (4), the sampling mirror (5), the photodetector PD (6), the reflector (7), the power meter (8) and the single-chip microcomputer (9) are all fixedly connected to the top of the optical platform (1).

3. According to the adaptive laser high-power stabilization device described in claim 2, the single-chip microcomputer (9) includes an analog-to-digital conversion port AD (91) and a serial port USB (92), and the photodetector PD (6) and the rotational translation stage (3) are connected to the single-chip microcomputer (9) through the analog-to-digital conversion port AD (91) and the serial port USB (92) respectively.

4. According to the adaptive laser high-power stabilization device described in claim 3, the single-chip microcomputer (9) controls the rotation angle of the rotary translation stage (3) through a PID algorithm.

5. According to the adaptive laser high-power stabilization device described in claim 1, the light beam output by the laser (2) passes through the center positions of the half-wave plate (30), the polarization beam splitter prism (4) and the sampling mirror (5) in sequence and then reaches the center position of the photodetector PD (6), and the reflected light beam of the sampling mirror (5) passes through the center position of the reflector (7) and then reaches the center position of the power meter (8).

6. According to the adaptive laser high-power stabilization device described in claim 1, the rotational translation stage (3) is coaxial and concentric with the half-wave plate (30).

Images