Laser aiming and positioning system and laser system

Abstract

The invention provides a laser aiming and positioning system and a laser system. According to the laser aiming and positioning system provided by the invention, the core problem of insufficient beam target coupling precision in the traditional sub-aperture target aiming technology is solved through a common-aperture light path design and a full-link dynamic correction mechanism. Specifically, the system realizes unification of space coordinate systems of a target detection light path and a laser emission light path by utilizing the characteristic of coaxial transmission of simulation light and main laser and combining with reverse light path monitoring of target surface diffuse reflection light, and thoroughly eliminates multi-stage coordinate transmission errors; meanwhile, by collecting imaging data of diffuse reflection light and simulation light in real time and based on a wavefront-free sensing self-adaptive correction strategy, light beam pointing drift and wavefront distortion caused by factors such as laser thermal deposition and environment vibration are dynamically compensated, and the beam target coupling precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and in particular to a laser aiming and positioning system and a laser system. Background Art

[0002] High-power lasers, due to their extreme compression in time and space, can form ultra-high power density in an instant. They are widely used to produce extreme physical conditions such as high temperature, high pressure, and high density under laboratory conditions. In this process, the coupling accuracy between the laser and the physical target is one of the key factors affecting the beam-target coupling efficiency, and the coupling accuracy mainly depends on the beam quality and pointing accuracy in the interaction area between the laser and the target.

[0003] Currently, many international and domestic laser devices use split-aperture target aiming and positioning technology, that is, the target aiming optical path and the laser emission optical path are not the same optical path. Although relatively high accuracy can be achieved in the aiming stage, since aiming and main emission cannot be carried out at the same time, there is a certain time interval between the two (generally about 30 minutes). The requirements for the stability of the beam quality and beam pointing within this time are relatively high. However, since the beam quality and pointing deviations output by most lasers are uncertain and random, such as the drift caused by amplifier thermal deposition between shots and the random jitter caused by laboratory environment vibration, these deviations are difficult to accurately correct or compensate without real-time monitoring and feedback, which will directly affect the target shooting accuracy. Therefore, it is necessary to establish a target aiming and positioning method that can monitor and control the beam quality and pointing in real time before the launch "zero".

[0004] In addition, during the aiming and positioning process of the sub-aperture target, it is necessary to use the telephoto microscope deployed on the vertical coordinate axis of the vacuum target sphere as a reference to determine the spatial position of the target, and calibrate the coordinate transfer relationship between the target monitoring sensor, target adjustment mechanism, and main optical path adjustment mechanism one by one, resulting in a complicated process and low efficiency.

[0005] In the split-aperture target aiming technology, there is a technical problem that the accuracy of beam-target coupling is not high enough. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies and provide a laser aiming and positioning system and a laser system to solve the technical problem that the beam-target coupling accuracy is not high enough in the split-aperture target aiming technology.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a laser aiming and positioning system, comprising: A main laser emitting unit, which is used to emit a main laser; A simulated light emitting unit, configured to emit simulated light; wherein the wavelength of the simulated light is different from that of the main laser, the simulated light is coaxial with the main laser, and forms a laser emission optical path and is emitted into the target chamber; A target chamber, which is used to generate diffusely reflected light from a target surface; wherein the diffusely reflected light is transmitted in reverse through the laser emission optical path to form a target detection optical path that is coaxial with the laser emission optical path and in the same spatial coordinate system; a monitoring module configured to collect imaging data of diffusely reflected light and simulated light from a target surface, and generate a first control signal based on at least the imaging data of the diffusely reflected light and simulated light from the target surface and a preset control strategy; A correction module is used to optimize the coaxiality and beam quality of the laser emission light path and the target detection light path by adjusting the direction and wavefront shape of the laser emission light path based on at least the first control signal.

[0008] Furthermore, the monitoring module at least includes: A line of sight monitoring unit is used to collect imaging data of diffusely reflected light and simulated light from the target surface, and then generate a first control signal based on the imaging data and a preset image quality evaluation function; wherein the first control signal is used to enable the correction module to optimize the tilt aberration and wavefront distortion of the laser emission optical path.

[0009] Furthermore, the image quality evaluation function is a gradient square sum function, an image information entropy minimization function, or a frequency domain contrast function.

[0010] Furthermore, the monitoring module also includes A coaxial monitoring unit is used to monitor the optical axis consistency of the main laser and the simulated light in real time and generate a second control signal based on the optical axis deviation; wherein the second control signal is used to adjust the beam combining parameters of the correction module to optimize the coaxial transmission state of the main laser and the simulated light.

[0011] Furthermore, the correction module includes: a fast reflecting mirror, configured to adjust the tilt aberration of the laser emission optical path based on the first control signal, and fine-tune the coaxiality of the main laser and the simulation light through the second control signal; A deformable mirror is used to adjust the wavefront distortion of the laser emission optical path based on the first control signal.

[0012] Furthermore, the correction module further includes: A beam combining device is used to make the simulated light coaxial with the main laser, and optimize the coaxial transmission state of the main laser and the simulated light based on the second control signal.

[0013] Furthermore, the target chamber is a vacuum target chamber, which has a built-in target illumination light source. The light of the target illumination light source is diffusely reflected on the experimental target to form diffusely reflected light on the target surface.

[0014] Furthermore, the simulated light emitting unit is continuously turned on and continuously emits simulated light during the aiming stage and the generating stage.

[0015] In a second aspect, the present invention provides a laser system, comprising: a laser aiming and positioning system as described in any one of the above, and a laser; wherein the laser is arranged between the main laser emitting unit and the target chamber.

[0016] Furthermore, the laser includes a transmission and focusing unit, a compressor unit, an AMP main laser unit and a stretcher unit which are connected in series.

[0017] Beneficial effects: The laser aiming and positioning system provided by the present invention solves the core problem of insufficient beam-target coupling accuracy in traditional sub-aperture target aiming technology through co-aperture optical path design and full-link dynamic correction mechanism. Specifically, the system utilizes the characteristics of coaxial transmission of analog light and main laser, combined with reverse optical path monitoring of diffusely reflected light from the target surface, to realize the spatial coordinate system of the target detection optical path and the laser emission optical path, completely eliminating the multi-level coordinate transmission error; at the same time, through real-time acquisition of imaging data of diffusely reflected light and analog light and based on an adaptive correction strategy without wavefront sensing, dynamic compensation is made for the beam pointing drift and wavefront distortion caused by factors such as laser thermal deposition and environmental vibration, thereby achieving an improvement in beam-target coupling accuracy. This technical solution effectively eliminates the multi-level coordinate transmission error, drift caused by time delay and manual operation error in the traditional sub-aperture design, improves the beam-target coupling accuracy, and significantly improves the accuracy and stability of the laser aiming and positioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a multi-aperture target aiming and positioning system provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a laser system provided by an embodiment of the present invention; Figure 3 Schematic diagram of a common-aperture target aiming and positioning system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention 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, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0020] A high-power laser device typically consists of a laser source unit, a beam transmission and shaping unit (including a stretcher, amplifier, compressor, and reflectors), a vacuum target chamber, and a target aiming and positioning system. The core task of the target aiming and positioning system is to ensure precise three-dimensional coupling between the laser beam and the target.

[0021] In the existing technology, the target aiming and positioning system can adopt a divided aperture design: Target monitoring optical path: Telephoto microscopes, CCD cameras and other equipment are deployed outside the vacuum target chamber to obtain target position information through independent optical paths; Laser emission optical path: The main laser enters the target chamber through the transmission and focusing unit and acts on the target point; Coordinate transfer link: It is necessary to calibrate the target room coordinate system → target monitoring sensor coordinate system → target adjustment mechanism coordinate system → laser emission optical path coordinate system in sequence to form a multi-level coordinate transfer chain.

[0022] In the sub-caliber target aiming technology, the system operation process is as follows: Target aiming stage: obtain the target posture through the target monitoring optical path and adjust the target position to the preset coordinates; Coordinate transfer and calibration: Manually switch to the laser emission optical path and calibrate the spatial relationship between the target adjustment mechanism and the laser emission optical path step by step; Launch phase: turn off the target monitoring system and start laser emission.

[0023] like Figure 1As shown, the related art provides a split-aperture target aiming and positioning system. Traditional split-aperture target aiming and positioning technology requires placing telephoto microscopes at different axial positions on the vacuum target chamber to acquire target pose data under the vacuum target chamber's coordinate conditions. The spatial relationship between the target pose acquired by each telephoto microscope and the target monitoring sensor, the target monitoring sensor and the target adjustment mechanism, and the main laser (simulated light) on the target monitoring sensor and the main optical path adjustment mechanism (the reflector and focusing mirror frame adjustment mechanism) is then calibrated. Based on this, the target is adjusted to the desired pose using the target adjustment mechanism. The target monitoring sensor simultaneously acquires the relationship between the target image (when illuminated) and the main laser (or simulated light), controls the main optical path adjustment mechanism, and spatially couples the main laser (or simulated light) to the target. After the mission is completed, the target sensor, main laser (or simulated light), target monitoring sensor, and main optical path adjustment mechanism are powered off, maintaining this state and entering launch preparation. This process takes about 30 minutes. All laser systems are in launch preparation state. If the target aiming status needs to be reviewed, the status of multiple systems needs to be switched, resulting in complex operation process and low efficiency.

[0024] The above technical solution has at least the following defects: 1. It is impossible to monitor and control factors such as the dynamic changes in beam quality and beam pointing between the end of the target and the actual launch, and they can only be regarded as random errors. In actual lasers, due to factors such as dynamic heat deposition, the beam quality and beam pointing will have obvious systematic drift and random drift over time. If the error cannot be corrected according to these changes, it will have a significant impact on the beam-target coupling accuracy. 2. The time from the end of aiming to the actual launch is long, which requires the target support structure to be very stable and not undergo any structural changes during the period. Once changes occur, it will have a negative impact on the beam-target coupling accuracy. 3. Since the target monitoring optical path and the emission optical path are not coaxial, the transmission path of the spatial coordinate relationship starts from the target posture, and then the spatial transmission relationship between the target monitoring sensor, target adjustment mechanism, and main optical path adjustment mechanism is calibrated one by one, resulting in cumbersome calculations, high technical difficulty, complex operation procedures, and low operating efficiency.

[0025] Understandably, in a split-aperture design, the target aiming optical path and the laser emission optical path reside in different coordinate systems. To achieve high-precision laser beam-target coupling, the system requires multiple coordinate transformations, often from target chamber coordinates to sensor coordinates, then to adjustment mechanism coordinates, and finally to laser optical path coordinates. This transformation not only increases system complexity but also inevitably introduces errors. Furthermore, each coordinate transformation may introduce errors, typically on the order of ±3-5μm. Sources of these errors include mechanical assembly tolerances and sensor calibration errors. These errors are propagated through multiple transformations, limiting the final beam-target coupling accuracy to the order of ±15-20μm. The accumulation of these errors limits the system's accuracy, preventing it from achieving the lower error levels required for high-precision applications. This means that each component in the laser system requires high-precision mechanical assembly to maintain a stable optical path. If assembly tolerances are large or there are slight misalignments between components, these errors will gradually accumulate during the optical path transmission. Furthermore, the sensors in the target monitoring system must be precisely calibrated to accurately detect target offsets. If the calibration is inaccurate, the signal output by the sensor will be affected by the error, thereby affecting the positioning accuracy of the entire system.

[0026] It's also understandable that existing laser aiming and positioning technologies utilize a time-sharing approach, resulting in a long time interval between the aiming phase and the laser emission phase, typically exceeding 30 minutes. This time interval makes the system susceptible to interference from various external factors, leading to error accumulation and offset, which in turn affects beam-target coupling accuracy. During the laser amplification process, especially in high-power lasers, the heat deposition effect of the amplifier can cause thermal deformation of the optical path. This can cause systematic deviation in the beam's direction over a period of time. Without a real-time monitoring and adjustment mechanism, this offset cannot be corrected promptly under time-sharing operation, thus affecting the final laser beam-target coupling accuracy. It's understandable that the physical deformation of optical components such as the amplifier and mirrors in the laser caused by heat can cause beam drift. If the system cannot monitor and correct the beam's direction in real time within a short period of time, the beam deviation will continue to affect subsequent laser emissions, resulting in reduced beam-target coupling accuracy. Furthermore, in addition to laser beam drift, the target's position may also shift, typically due to factors such as environmental vibration or temperature fluctuations. Even slight changes in the target support structure can cause target position shift. This offset cannot be corrected in real time during time-sharing operations, which further exacerbates the error.

[0027] It is also understandable that in the prior art, because the optical paths of the target monitoring system and the laser emission system are not coaxial, repeated system switching is required during system debugging, such as shutting down the simulated light and switching the sensor power supply. These operations not only increase the complexity of the workflow but are also prone to introducing human error.

[0028] Therefore, the shortcomings of existing technologies are primarily manifested in three aspects: error accumulation in the spatial dimension, uncontrollable errors in the temporal dimension, and human error in the process dimension. These issues not only limit the precise coupling between the laser beam and the target but also significantly reduce the efficiency and reliability of the system. Therefore, to improve the accuracy of beam-target coupling and address the shortcomings of existing technologies, new technical solutions are urgently needed to address these issues, particularly in the areas of real-time monitoring and correction of beam quality and beam pointing, thereby achieving higher-precision laser aiming and positioning.

[0029] This embodiment provides a laser aiming and positioning system, including: The main laser emitting unit is used to emit the main laser.

[0030] In this embodiment, the main laser emitting unit may be a seed light source of a laser, for example, an ultrashort pulse oscillator, a fiber laser, or a semiconductor laser.

[0031] The simulated light emitting unit is used to emit simulated light; wherein the wavelength of the simulated light is different from the wavelength of the main laser, the simulated light is coaxial with the main laser, and forms a laser emission optical path and is emitted into the target chamber.

[0032] In this embodiment, the analog light emitting unit may be a semiconductor laser or a fiber-coupled laser, etc.

[0033] It is understandable that the wavelength of the simulated light must be different from the main laser wavelength and be in the non-gain band of the laser amplification medium to avoid accidental amplification of the simulated light.

[0034] In this embodiment, the main laser emitted by the main laser emitting unit can be coaxially combined with the simulated light by a beam combining device. Specifically, the beam combining device can be a dichroic mirror or a polarization beam splitter prism.

[0035] In this embodiment, the difference between the wavelength of the simulation light and the wavelength of the main laser light may be greater than 100 nm.

[0036] A target chamber is used to generate diffusely reflected light from a target surface; wherein the diffusely reflected light is transmitted in reverse through the laser emission light path to form a target detection light path that is coaxial with the laser emission light path and is in the same spatial coordinate system.

[0037] In this embodiment, the target chamber is a vacuum target chamber, which houses a target illumination light source. Light from the target illumination light source is diffusely reflected from the experimental target, forming diffusely reflected light from the target surface. The vacuum target chamber can be a spherical vacuum target chamber. Specifically, the experimental target can be placed at the center of the spherical vacuum target chamber. A zero-position monitoring unit establishes a coordinate system, calibrates the target's initial position, and adjusts the experimental target's position.

[0038] Specifically, the vacuum target chamber can be constructed of stainless steel or aluminum alloy, with the inner surface coated with a high-reflectivity film (such as gold or dielectric film) to reduce stray light interference. The experimental target can be fixed to the geometric center of the spherical cavity using a six-dimensional target adjustment mechanism, ensuring controllable laser incident angle. The target surface can be microstructured (with a sanded surface or micropore array) to enhance the intensity and directional uniformity of diffusely reflected light. The wavelength of the target illumination light source can be separated from the main laser wavelength (for example, 1064nm main laser and 532nm target illumination light) to avoid spectral crosstalk. Furthermore, the target illumination light source can be evenly distributed along the inner wall of the spherical cavity, ensuring omnidirectional illumination of the target surface.

[0039] The monitoring module is at least used to collect imaging data of the target surface diffusely reflected light and the simulated light, and generate a first control signal based at least on the imaging data of the target surface diffusely reflected light and the simulated light and a preset control strategy.

[0040] In this embodiment, the monitoring module can be used to collect imaging data of diffusely reflected light and simulated light from the target surface, and generate a first control signal based at least on the imaging data of the diffusely reflected light and simulated light from the target surface and a preset control strategy. Specifically, the monitoring module can include a line of sight monitoring unit, which can be used to collect imaging data of diffusely reflected light and simulated light from the target surface, and then generate a first control signal based on the imaging data and a preset image quality evaluation function; wherein the first control signal is used to cause the correction module to optimize the tilt aberration and wavefront distortion of the laser emission optical path.

[0041] In this embodiment, the preset control strategy may include: Data preprocessing, such as Gaussian filtering, background subtraction, and grayscale normalization of the spot image to extract the effective signal area.

[0042] Error extraction, for example, can calculate the tilt aberration based on the center of mass offset of the spot (center of mass coordinate difference); extract the wavefront Zernike coefficient based on the spot shape distortion (ellipticity, annular fringes).

[0043] Control signal generation, for example, can map tilt aberration to FSM tilt adjustment and wavefront distortion to DM surface shape adjustment, and avoid parameter conflicts through decoupling algorithms. Stochastic Parallel Gradient Descent (SPGD) or hill climbing algorithms can be used, using the image quality evaluation function as feedback to iteratively approximate the optimal correction parameter combination.

[0044] In this embodiment, the monitoring module can also be used to monitor the optical axis alignment of the master laser and the simulated light in real time and generate a second control signal based on the optical axis deviation. The second control signal is used to adjust the beam combining parameters of the correction module to optimize the coaxial transmission state of the master laser and the simulated light. Specifically, the monitoring module can also include a coaxial monitoring unit.

[0045] A correction module is used to optimize the coaxiality and beam quality of the laser emission light path and the target detection light path by adjusting the direction and wavefront shape of the laser emission light path based on at least the first control signal.

[0046] In this embodiment, the correction module can be used to optimize the coaxiality and beam quality of the laser emission optical path and the target detection optical path by adjusting the direction and wavefront shape of the laser emission optical path based on the first control signal. For example, the correction module can include a fast reflector and a deformable mirror.

[0047] In this embodiment, the correction module can also be used to make the simulated light coaxial with the main laser, and optimize the coaxial transmission state of the main laser and the simulated light based on the second control signal. For example, the correction module can also include a beam combining device.

[0048] In this embodiment, the correction module can also be used to fine-tune the coaxiality of the main laser and the simulation light through the second control signal, for example, by using a fast reflection mirror.

[0049] The laser aiming and positioning system provided in this embodiment solves the core problem of insufficient beam-target coupling accuracy in traditional split-aperture target aiming technology through co-aperture optical path design and full-link dynamic correction mechanism. Specifically, the system utilizes the characteristics of coaxial transmission of simulated light and main laser, combined with reverse optical path monitoring of diffusely reflected light on the target surface, to realize the spatial coordinate system of target detection optical path and laser emission optical path, and completely eliminates multi-level coordinate transmission errors; at the same time, through real-time acquisition of imaging data of diffusely reflected light and simulated light and based on an adaptive correction strategy without wavefront sensing, it dynamically compensates for the beam pointing drift and wavefront distortion caused by factors such as laser thermal deposition and environmental vibration, thereby achieving an improvement in beam-target coupling accuracy. This technical solution effectively eliminates the multi-level coordinate transmission error, drift caused by time delay and manual operation error in the traditional split-aperture design, improves the beam-target coupling accuracy, and significantly improves the accuracy and stability of the laser aiming and positioning system.

[0050] In some embodiments, the monitoring module includes at least: A line of sight monitoring unit is used to collect imaging data of diffusely reflected light and simulated light from the target surface, and then generate a first control signal based on the imaging data and a preset image quality evaluation function; wherein the first control signal is used to enable the correction module to optimize the tilt aberration and wavefront distortion of the laser emission optical path.

[0051] In this embodiment, the line of sight monitoring unit may include an optical acquisition subsystem. Specifically, the signal sources of the optical acquisition subsystem are the diffusely reflected light from the target surface and the transmitted portion of the simulated light. The diffusely reflected light from the target surface is the Lambertian diffusely reflected light generated by the experimental target being illuminated by the target illumination light source, and it carries information about the tilt and wavefront errors of the subsequent optical path (target chamber → beam splitter). The simulated light, after being transmitted through the beam splitter, returns along the original path via the conic reflector (CR), carrying information about the alignment errors of the preceding optical path (simulated light source → beam splitter). The imaging sensor used in this optical acquisition subsystem can be a high-resolution CCD or CMOS camera, which can capture the intensity distribution and morphological characteristics of the light spot.

[0052] In this embodiment, the line of sight monitoring unit may include a data processing and evaluation subsystem. This data processing and evaluation subsystem may further include an image quality evaluation function and an adaptive optimization algorithm. The adaptive optimization algorithm may employ a stochastic parallel gradient descent (SPGD) or hill climbing algorithm to iteratively approximate the optimal image quality score by randomly perturbing correction module parameters (FSM tilt angle, DM surface shape).

[0053] In this embodiment, the line of sight monitoring unit may include a control signal generation and feedback subsystem. Specifically, this control signal generation and feedback subsystem first performs noise reduction, normalization, and background subtraction on the captured spot image to extract the effective signal area. It then calculates the current spot score based on a preset image quality evaluation function (sum of squared gradients). Next, it slightly adjusts the FSM tilt angle or DM surface shape, recaptures the image, and calculates the score to determine the optimization direction. Finally, iterates continuously until the score reaches a threshold, generating a steady-state control signal.

[0054] This embodiment realizes dynamic closed-loop correction of laser emission optical path errors through the wavefront sensor-free optimization mechanism of the line of sight monitoring unit: based on the reverse coaxial imaging data of the diffusely reflected light and the simulated light on the target surface, the control signal is generated in real time using the image quality evaluation function to drive the correction module to synchronously optimize the tilt aberration and wavefront distortion of the light beam. This design eliminates the accumulation of coordinate transfer errors caused by optical path separation in traditional aperture-split technology, and directly links the spatial consistency of the emission and monitoring optical paths through the principle of optical path reversibility, significantly improving the beam-target coupling accuracy; at the same time, the dynamic correction mechanism can suppress drift caused by laser thermal deposition, environmental vibration, etc. in real time, avoiding the error amplification caused by time delay in traditional methods. In addition, the adaptive optimization process without the need for a wavefront sensor greatly simplifies the system complexity and operating steps, significantly shortens the launch preparation cycle, and provides a new high-precision and high-efficiency solution for high-power laser applications.

[0055] In some embodiments, the image quality evaluation function is a gradient square sum function, an image information entropy minimization function, or a frequency domain contrast function.

[0056] In this embodiment, the gradient square sum function quantifies the sharpness and edge definition of the light spot by calculating the square sum of the brightness gradients of adjacent pixels in the image.

[0057] In this embodiment, the image information entropy minimization function can optimize the energy concentration. The information entropy measures the randomness of the image grayscale distribution. The lower the entropy value, the more concentrated the energy.

[0058] In this embodiment, the frequency domain contrast function can convert the spot image into the frequency domain through Fourier transform, and calculate the energy ratio of the high-frequency component to evaluate the contrast.

[0059] This embodiment can accurately evaluate the quality of the laser beam by introducing image quality evaluation functions such as the gradient sum of squares function, image information entropy minimization function, or frequency domain contrast function. These functions quantitatively analyze the tilt aberration, wavefront distortion, and image clarity of the beam from different angles. The gradient sum of squares function can effectively identify changes in the slope of the beam, the image information entropy minimization function can optimize the clarity of the beam, and the frequency domain contrast function helps to improve the contrast and spatial resolution of the beam. Through these image quality evaluation functions, the system can analyze and optimize the quality of the laser beam in real time, ensure high-precision coupling between the laser beam and the target, improve the stability and accuracy of the system, reduce errors and the manual intervention required for correction, and thus improve the efficiency and reliability of the entire laser aiming and positioning system.

[0060] In some embodiments, the monitoring module further comprises: A coaxial monitoring unit is used to monitor the optical axis consistency of the main laser and the simulated light in real time and generate a second control signal based on the optical axis deviation; wherein the second control signal is used to adjust the beam combining parameters of the correction module to optimize the coaxial transmission state of the main laser and the simulated light.

[0061] In this embodiment, the coaxial monitoring unit may include an optical detection subsystem and an optical axis deviation quantification and signal generation subsystem. Specifically, the optical detection subsystem may include a spectroscopic sampling device (dichroic beam splitter) that can embed a beam splitter with high transmittance (main laser wavelength) and high reflectivity (simulated light wavelength) in the main light path, separating a portion of the energy (approximately 5%) from the dual light paths to the monitoring channel. The optical detection subsystem may also include a light spot position detection device (four-quadrant detector) that can calculate the center of mass offset based on the energy difference between the light spot in the four quadrants. The optical axis deviation quantification and signal generation subsystem converts the pixel-level coordinate difference between the center of mass of the main laser and simulated light spots into an angular deviation, which is then input into a proportional-integral-differential controller to output a second control signal (voltage or stepper motor pulse).

[0062] In this embodiment, the second control signal can adjust the beam combining parameters of the correction module (beam combining device).

[0063] This embodiment introduces a coaxial monitoring unit that monitors the optical axis consistency of the main laser and the simulated light in real time, ensuring that they maintain a coaxial transmission state. By detecting optical axis deviation, the second control signal generated by the coaxial monitoring unit can instantly adjust the beam combining parameters of the correction module to optimize the beam combining accuracy of the main laser and the simulated light. This technical solution effectively eliminates errors caused by optical axis deviation, ensures the stability and high-precision coupling of the laser beam, and avoids degradation of beam quality or pointing errors. Through automated adjustment, the need for human intervention is reduced, the system's accuracy, stability, and work efficiency are improved, and the performance and reliability of the laser aiming system are significantly enhanced.

[0064] In some embodiments, the correction module includes: a fast reflecting mirror, configured to adjust the tilt aberration of the laser emission optical path based on the first control signal, and fine-tune the coaxiality of the main laser and the simulation light through the second control signal; A deformable mirror is used to adjust the wavefront distortion of the laser emission optical path based on the first control signal.

[0065] In this embodiment, a fast steering mirror (FSM) compensates for the tilt aberration (beam pointing deviation) of the laser emission optical path and fine-tunes the coaxiality of the main laser and the simulated light by quickly adjusting the inclination angle of the mirror.

[0066] In this embodiment, a deformable mirror (DM) corrects the wavefront distortion (defocus, astigmatism) of the laser emission optical path by locally deforming the curvature of the mirror surface, thereby improving the beam quality.

[0067] This embodiment achieves multi-dimensional precision correction of optical path errors through the division of labor and cooperation between a fast reflector (FSM) and a deformable mirror (DM). The FSM compensates for beam tilt aberration (pointing deviation caused by vibration or thermal drift) at high speed based on the first control signal, and fine-tunes the coaxiality of the main laser and the simulated light through the second control signal to eliminate residual errors in the assembly of the beam combiner. The DM dynamically adjusts the wavefront phase distribution based on the first control signal to correct high-order wavefront distortions such as defocus and astigmatism, thereby improving the beam quality. This design solves the problems of error coupling and insufficient response bandwidth in traditional single-device correction through spatially separated correction and dynamic priority control (tilt correction is faster than wavefront correction), significantly improving the beam-target coupling accuracy and long-term stability.

[0068] In some embodiments, the correction module further includes: A beam combining device is used to make the simulated light coaxial with the main laser, and optimize the coaxial transmission state of the main laser and the simulated light based on the second control signal.

[0069] This embodiment introduces a beam combining device to ensure that the simulated light and the main laser remain coaxial during transmission, thereby ensuring the stability and accuracy of the laser beam. The beam combining device receives a second control signal generated by the coaxial monitoring unit and adjusts the beam combining parameters of the optical path in real time to optimize the coaxial transmission state of the simulated light and the main laser. In this way, the system can dynamically correct errors caused by optical axis deviation, ensuring that the two beams always maintain the same optical axis, thereby improving the accuracy and stability of the laser beam. This technical solution effectively eliminates deviations caused by inconsistent beam pointing, improves the coupling accuracy between the laser and the target, enhances the reliability and efficiency of the system, and reduces errors caused by human intervention or environmental factors.

[0070] In some embodiments, the target chamber is a vacuum target chamber having a built-in target illumination light source. Light from the target illumination light source is diffusely reflected on the experimental target to form diffusely reflected light on the target surface.

[0071] This embodiment significantly improves the signal quality and monitoring reliability of the diffusely reflected light from the target surface through the collaborative design of the vacuum target chamber and the multi-angle target illumination light source. The vacuum environment effectively eliminates air scattering and oxidation interference, ensuring the stability of the surface characteristics of the experimental target. The built-in wide-spectrum target illumination light source (wavelength separated from the main laser) illuminates the target surface at uniform multiple angles, which can trigger isotropic Lambertian diffuse reflection and generate a high signal-to-noise ratio diffuse reflection light signal. When this signal is transmitted in reverse through the laser emission optical path, it fully carries the optical path tilt and wavefront distortion information, enabling the line of sight monitoring unit to accurately analyze the beam pointing deviation and phase error. At the same time, the reversibility of the optical path enables seamless switching between the "emission-monitoring" state, significantly shortening the system calibration cycle and providing a stable and efficient experimental environment for high-power laser applications.

[0072] In some embodiments, the simulated light emitting unit is continuously turned on and continuously emits simulated light during the aiming phase and the generating phase.

[0073] This embodiment achieves real-time closed-loop error correction throughout the entire process by simulating a continuous light-on mechanism during the aiming and generation phases. This continuous-on design simplifies the operational process and significantly reduces launch preparation time. Furthermore, through continuous optical path feedback, it enhances the system's dynamic adaptability to complex operating conditions (such as transient target surface deformation and laser power fluctuations), providing continuous and robust correction for the reliable operation of high-power lasers.

[0074] This embodiment provides a laser system, comprising: a laser aiming and positioning system as described in any one of the above embodiments and a laser; wherein the laser is arranged between the main laser emitting unit and the target chamber.

[0075] In this embodiment, the laser includes a transmission and focusing unit, a compressor unit, an AMP main laser unit, and a stretcher unit connected in series.

[0076] like Figure 3 As shown, in a specific embodiment, a laser system is provided, which may include: a simulation light and a main laser starting point, an adjustment optical path module and a main laser module. The simulation light and the main laser starting point are used to emit a main laser and a simulation light of different wavelengths. The main laser and the simulation light of different wavelengths are combined and made coaxial by a beam combiner in the adjustment optical path module. The adjustment optical path module may also include supporting components, a line of sight monitoring unit, a coaxial monitoring unit, and an FSM and DM unit. The main optical path module may include a laser and a target chamber. The laser includes a transmission and focusing unit, a compressor unit, an AMP main laser unit, and a stretcher unit connected in series in sequence. The target chamber is used to generate diffusely reflected light from the target surface; wherein, the diffusely reflected light is transmitted in reverse through the laser emission optical path to form a target detection optical path that is coaxial with the laser emission optical path and is in the same spatial coordinate system.

[0077] In a specific embodiment, a common aperture target aiming and positioning system is provided. The technical problems to be solved by the system are: The common aperture target aiming technology is used to make the target monitoring optical path and the laser emission optical path coaxial, and the two are in the same coordinate relationship. The target aiming process only requires adjusting the relative posture relationship between the target and the laser; By introducing simulated light with a wavelength different from the main laser, the emission and target monitoring optical paths can be connected in series in real time. Combined with technologies such as beam pointing control and wavefront correction, real-time monitoring and control of the entire link and process can be achieved. By configuring a coaxial monitoring unit, the deviation between the simulated light and the main laser can be monitored and corrected in real time; By configuring the line of sight monitoring unit, the coaxial deviation between the emission light path and the target monitoring light path can be monitored and corrected in real time.

[0078] The common aperture target aiming and positioning system may include: The target for aiming and positioning is called the experimental target. The experimental target is placed in the center of the spherical vacuum target chamber. The zero position monitoring unit establishes a coordinate system, calibrates the initial state of the target position, and adjusts the experimental target position.

[0079] During the target alignment process, the simulated light unit (shown in the figure) emits simulated light. The simulated light differs in wavelength from the laser emitted by the front-end unit and is not amplified by the laser assembly (composed of the transmission and focusing unit, compressor unit, amplifier AMP, and stretcher unit shown in the figure), nor does it need to be shut down during target practice. The simulated light and laser beam are combined in the assembly and aligned on the same axis, so the simulated light used to correct errors in the emission optical path is also effective for the front-end unit laser.

[0080] The simulated light is split into reflected and transmitted light by a plane mirror. The transmitted light is then reversed 180 degrees by a corner reflector (CR) unit and ultimately enters the boresight monitoring unit. The reflected light then passes through the fast steering mirror (FSM) unit and the deformable mirror (DM) unit, is monitored by the coaxial monitoring unit, and finally enters the spherical vacuum target chamber.

[0081] The coaxial monitoring device monitors and corrects the deviation between the simulated light and the main laser in real time, so that the simulated light and the laser light have optical axis consistency.

[0082] The spherical vacuum target chamber is equipped with a target illumination light source. The light from the target illumination light source is diffusely reflected on the rough surface of the experimental target. Part of the weak light passes through the laser in reverse, passes through the DM unit and the FSM unit, and finally enters the line of sight monitoring unit.

[0083] The line of sight detection unit selects a suitable image quality evaluation function as a standard for the collected image, adopts a correction method without a wavefront sensor, and corrects the laser emission optical path in real time through the DM unit and FSM unit, and performs image clarification processing on the image of the emission optical path, so as to complete real-time monitoring and correct the deviation between the emission optical path and the target monitoring optical path.

[0084] The FSM unit primarily consists of a reflective mirror, an actuator, a support structure, an angle sensor, a drive circuit, and a control system. FSM units include piezoelectric ceramic FSMs, voice coil motor FSMs, and MEMS (Micro Electro Mechanical System) FSMs. The FSM unit is a critical component of the target positioning and aiming system. Driven by the drive elements, the FSM controls the rapid, high-frequency rotation of the reflective mirror, achieving high-speed, precise pointing, stabilization, and tracking of the light beam. It precisely controls the beam's direction and corrects for tilt errors in the optical path. With its fast response and high accuracy, the FSM unit is ideal for correcting drift and tilt aberrations in the laser's pointing direction within the system's optical path, improving beam-to-target coupling accuracy.

[0085] Specifically, the core principle of a fast mirror is to change the direction of incident light by precisely controlling the mirror's tilt angle. Signals collected by a coaxial monitor are used to adjust the FSM's tilt angle, ensuring the two beams are coaxial and on the same optical path. Essentially, it's a controlled, active mirror. The deformation of the actuator changes the mirror's tilt angle, thereby altering the beam's direction. The only difference lies in the choice of actuator, such as piezoelectric ceramics (which deform under high voltage), mechanical structure, or voice coil motor.

[0086] A DM unit consists of a reflective mirror, discrete actuators, a high-voltage loading device, and a control system. Types include discrete surface deformable mirrors, continuous surface deformable mirrors, liquid crystal light modulators, and acousto-optic modulators. Each actuator corresponds to a response function (i.e., the mapping between the voltage applied to it and its degree of deformation). By applying different drive voltages to each actuator, the optical path length of the light wavefront is altered, thereby changing the phase structure of the incident light wavefront. This phase shapes the light wavefront and eliminates wavefront aberrations (such as defocus and astigmatism) in the optical path. DM units offer advantages such as a short drive stroke, fast response speed, minimal adaptation error, low light energy loss, high spatial resolution, and consistent control of absolute phase. They are suitable for beam shaping and improving beam quality.

[0087] Specifically, the core principle of the deformable mirror is to control the shape of the mirror so that it can dynamically change the wavefront of the reflected light, thereby correcting the beam distortion caused by atmospheric disturbances, mirror errors or other factors.

[0088] Specifically, the joint correction of FSM and DM is that FSM adjusts the pointing direction of light and corrects tilt aberration, while DM corrects other wavefront distortions caused by optical path errors. This is the correction process. In the process of correcting aberrations, DM improves the quality of the main laser beam and makes the beam energy more concentrated. The positions of DM and FSM are interchangeable, and the order of priority is not limited in the optical path design of this embodiment. In control, DM and FSM also have a coupling relationship because they are in the same system. That is, adjusting any one of them may affect the existing correction effect of the other unit, so that the other unit needs to be corrected again, and vice versa. Therefore, this can be solved by a decoupling algorithm.

[0089] This embodiment adopts a co-aperture target aiming optical path design, and the target monitoring optical path is coaxial with the laser emission optical path. In the prior art, the target monitoring optical path and the laser emission optical path are not coaxial, resulting in a lengthy transmission path for the spatial coordinate relationship from the target to each adjustment mechanism during the aiming process. The coupling transformation calculation between multiple spatial coordinate systems is complex, and coordinate system conversion errors, numerical calculation errors, and transmission errors are prone to occur. In this embodiment, the two optical paths are coaxial and in the same spatial coordinate system, so there is no coordinate coupling transformation process of the old method. The aiming process only needs to adjust the relative posture relationship between the target and the laser, which can reduce the calculation complexity and improve the correction efficiency. At the same time, because the two optical paths of aiming and emission are not coaxial in space in the prior art, the two stages of aiming and emission need to be separated in time. It takes a long time from the completion of aiming to emission, and it is impossible to correct the beam drift and target support mechanism errors that occur over time, affecting the beam-target coupling accuracy. If the target aiming status is to be reviewed, the system status needs to be switched back and forth, which is time-consuming and labor-intensive and reduces efficiency. However, in this method, the optical paths of the target monitoring and launching systems are coaxial in space, and therefore synchronized in time. The target aiming monitoring system corrects the system aiming error in real time, and launch can be carried out as soon as the aiming is completed without switching the system. This method can correct errors that cannot be handled by existing methods, simplifies the launch process, and improves aiming accuracy and system operation efficiency.

[0090] This method introduces simulated light that can be emitted in tandem with the laser in real time. Due to the difference in wavelength between the simulated light and the laser, the simulated light is not amplified by the laser and can remain on continuously. Existing methods require the relationship between the simulated light and the target image to adjust the target position, and the simulated light is turned off during the emission phase. In this method, the simulated light corrects for errors in the optical path of the laser and simulated photosynthesis link. The evaluation function only focuses on the quality of the target image under the target illumination source, rather than the relationship between the simulated light and the target image. The simulated light participates in real-time target aiming and monitoring throughout the entire process.

[0091] This implementation combines a DM and FSM to dynamically correct laser targeting errors in real time. The FSM precisely controls the beam direction, corrects for tilt aberrations, and eliminates laser pointing drift caused by dynamic heat deposition. The DM corrects for higher-order aberrations in the light wavefront, ensuring beam quality. The FSM boasts a large travel range and fast response, while the DM has a small drive range, resulting in high spatial resolution and precision. The combination of these two simulates light to correct errors that are unresolvable using existing methods.

[0092] This implementation utilizes a co-aperture target aiming optical path design. The target monitoring optical path and the laser emission optical path are coaxial and share the same spatial coordinate relationship. The target monitoring system's illumination source is located inside the spherical vacuum target chamber, while the monitoring system is located outside. Calibration of the target monitoring optical path calibrates the laser emission optical path, correcting errors in real time and eliminating the complex process of switching systems. Laser emission can be performed immediately after calibration.

[0093] This embodiment uses continuously on simulated light. The simulated light remains on all the time, eliminating the need to shut it down during laser emission. There's no need to switch between laser and simulated light as with existing methods. The simulated light participates in the correction process in real time, eliminating the need to consider the relationship between the target image and the simulated light during the correction process.

[0094] This embodiment uses CR to transmit the transmitted light of the simulated light to the line-of-sight monitoring system to correct the error of the beam combiner. The coaxial monitoring system monitors and corrects the error between the simulated light and the laser, so that the laser and simulated light maintain optical axis consistency.

[0095] This implementation uses a combination of FSM and DM to correct errors in the target-aiming optical path. The FSM and DM adjust the image entering the boresight monitoring system. The process of image sharpening is the process of correcting the targeting error. The FSM adjusts the beam's direction, while the DM eliminates wavefronts to ensure beam quality.

[0096] This embodiment can incorporate a wavefront sensor or far-field camera into the boresight monitoring system. The DM unit uses a wavefront correction method with a wavefront detector to more accurately correct aberrations. The DM unit can also house a liquid crystal spatial light modulator (SLM), which modulates the phase and amplitude of light, allowing for precise correction of laser aberrations on a smaller scale.

[0097] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0098] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0099] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0100] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0101] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A laser aiming and positioning system, characterized in that: include: A main laser emitting unit, which is used to emit a main laser; A simulated light emitting unit, configured to emit simulated light; wherein the wavelength of the simulated light is different from that of the main laser, the simulated light is coaxial with the main laser, and forms a laser emission optical path and is emitted into the target chamber; A target chamber, which is used to generate diffusely reflected light from a target surface; wherein the diffusely reflected light is transmitted in reverse through the laser emission optical path to form a target detection optical path that is coaxial with the laser emission optical path and in the same spatial coordinate system; a monitoring module configured to collect imaging data of diffusely reflected light and simulated light from a target surface, and generate a first control signal based on at least the imaging data of the diffusely reflected light and simulated light from the target surface and a preset control strategy; A correction module is used to optimize the coaxiality and beam quality of the laser emission light path and the target detection light path by adjusting the direction and wavefront shape of the laser emission light path based on at least the first control signal.

2. The system according to claim 1, wherein: The monitoring module at least includes: A line of sight monitoring unit is used to collect imaging data of diffusely reflected light and simulated light from the target surface, and then generate a first control signal based on the imaging data and a preset image quality evaluation function; wherein the first control signal is used to enable the correction module to optimize the tilt aberration and wavefront distortion of the laser emission optical path.

3. The system according to claim 2, characterized in that The image quality evaluation function is a gradient square sum function, an image information entropy minimization function or a frequency domain contrast function.

4. The system according to claim 2, wherein: The monitoring module also includes A coaxial monitoring unit is used to monitor the optical axis consistency of the main laser and the simulated light in real time and generate a second control signal based on the optical axis deviation; wherein the second control signal is used to adjust the beam combining parameters of the correction module to optimize the coaxial transmission state of the main laser and the simulated light.

5. The system according to claim 4, characterized in that The correction module includes: a fast reflecting mirror, configured to adjust the tilt aberration of the laser emission optical path based on the first control signal, and fine-tune the coaxiality of the main laser and the simulation light through the second control signal; A deformable mirror is used to adjust the wavefront distortion of the laser emission optical path based on the first control signal.

6. The system according to claim 5, characterized in that The correction module also includes: A beam combining device is used to make the simulated light coaxial with the main laser, and optimize the coaxial transmission state of the main laser and the simulated light based on the second control signal.

7. The system according to claim 1, wherein: The target chamber is a vacuum target chamber, which is equipped with a target illumination light source. The light from the target illumination light source is diffusely reflected on the experimental target to form diffusely reflected light on the target surface.

8. The system according to claim 1, wherein: The simulated light emitting unit is continuously turned on and continuously emits simulated light during the aiming stage and the generating stage.

9. A laser system, characterized in that: include: The laser aiming and positioning system and laser according to any one of claims 1 to 8; wherein the laser is arranged between the main laser emitting unit and the target chamber.

10. The system according to claim 9, characterized in that The laser comprises a transmission and focusing unit, a compressor unit, an AMP main laser unit and a stretcher unit which are connected in series in sequence.

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