Nonlinear optical crystal homologous multi-path parallel accelerated aging device

Abstract

The application provides a kind of nonlinear optical crystal isogenous multi-channel parallel accelerated aging device in the field of engineering optics and laser technology.Based on single-link laser oscillation, a one-dimensional high-order Hermite-Gaussian beam is generated, and using the m+1 isogenous lobes naturally split in its cross section, after beam shaping module expansion separation, multiple parallel beams are formed and irradiated to different transverse positions of the same crystal sample or different crystal samples, and synchronous acceleration test is realized under the same and synchronous aging environment conditions.The serial test in time dimension is converted into parallel operation in space dimension, while keeping the single device physical aging mechanism unchanged, the test throughput and data reliability are improved, which is suitable for batch screening and life rapid evaluation of nonlinear optical crystal.Aiming at the technical cognition that high-order Hermite-Gaussian mode is usually suppressed, the natural lobes and isogenous common mode characteristics are reversely utilized, and multiple stress level synchronous test optical path is constructed without replicating multiple solid-state lasers.

Description

Technical Field

[0001] This invention relates to the fields of engineering optics and laser technology, and in particular to a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device. Background Technology

[0002] Nonlinear optical crystals are widely used in high-power laser equipment, but they are prone to performance degradation under high peak laser irradiation, such as decreased transmittance and reduced damage threshold, which severely limits device lifespan. Currently, in industrial applications such as high-power ultraviolet, deep ultraviolet, and mid-infrared lasers, the lifespan of nonlinear crystals has become a major industry concern, necessitating the development of an efficient accelerated aging solution.

[0003] In the field of reliability assessment of semiconductor laser chips, due to the low cost and ease of integration of a single chip, the industry generally adopts a "multi-chip parallel aging" test scheme: by driving multiple chips to run simultaneously, a large amount of failure statistics are accumulated in a short period of time, thereby achieving high-efficiency lifetime assessment. However, the aging test of nonlinear optical crystals cannot directly adopt the above parallel scheme. The fundamental reason is that the aging of nonlinear optical crystals requires a high-power solid-state laser as a front-end pump source. Unlike semiconductor lasers, high-power solid-state laser systems are complex, extremely expensive, bulky, and have stringent thermal management requirements. This makes it difficult to construct a parallel aging optical path by simply replicating multiple independent solid-state lasers, as this presents a dual dilemma in engineering: uncontrolled cost and system scale explosion.

[0004] As a result, current aging assessments of nonlinear optical crystals still heavily rely on the traditional "single laser, single optical path, serial testing" approach: using the same laser to irradiate multiple crystal samples or multiple points on a single sample one by one. While this approach controls hardware costs, its testing efficiency is extremely low, leading to a long-standing lack of sufficient and systematic aging data in the field. This data scarcity, in turn, severely restricts the quantitative evaluation and rapid iteration of nonlinear optical crystal growth processes, coating technologies, and device packaging levels.

[0005] In summary, how to achieve multi-path, homogeneous, and highly consistent laser beam injection based on one (or very few) solid-state laser preamplifiers, while avoiding inconsistent test benchmarks caused by light source fluctuations, has become the core bottleneck restricting the development of accelerated aging technology for nonlinear optical crystals.

[0006] Existing aging assessment technologies mainly rely on single-beam point-by-point irradiation, which is inefficient and cannot meet the needs of rapid screening of batch crystals and production line consistency testing. Some multi-beam testing schemes use mechanical beam splitting or fiber optic splitting to achieve parallel irradiation, but each optical path originates from a different physical path. The power drift and pulse time fluctuation of the laser source act independently on each test point in the form of differential mode interference, resulting in inconsistent experimental benchmarks and limited data reliability.

[0007] In related technologies, higher-order Hermitian-Gaussian modes are usually regarded as non-fundamental modes that need to be suppressed and are suppressed by means of intracavity mode selection, etc. A small number of studies mainly focus on the generation and conversion of higher-order modes, and pay insufficient attention to their high-power lobed characteristics for engineering applications in parallel aging tests. Summary of the Invention

[0008] This invention provides a homogeneous multipath parallel accelerated aging device for nonlinear optical crystals, transforming sequential testing in the time dimension into parallel operations in the spatial dimension. While maintaining the physical aging mechanism of a single device, it improves test throughput and data reliability, making it suitable for batch screening and rapid lifetime assessment of nonlinear optical crystals. Addressing the common understanding that higher-order Hermitian-Gaussian modes are typically suppressed, this invention reverses this understanding by utilizing their natural lobes and homogeneous common-mode characteristics to construct a multi-stress horizontal synchronous test optical path without requiring the replication of multiple solid-state lasers.

[0009] This invention provides a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device, including a beam generation module that generates a Hermitian-Gaussian beam based on a single laser oscillation / amplification link. The Hermitian-Gaussian beam employs a one-dimensional higher-order mode. The order m is not less than 3; wherein the Hermit-Gaussian beam has multiple lobes with gradient intensity distribution and spatial separation. For distribution along the y-axis The normalized amplitude distribution of the optical field. It can be represented as: ; Where A is the normalized optical field amplitude coefficient. , w o and w ( z ) are respectively z = 0 and z Positional fundamental model ( HG 00 Waist radius, molecule Normalization coefficient (make) ), defined as: ; Let x and y be the transverse Gaussian distribution envelope of the light field amplitude, and z be the transverse coordinates of the light field. for Hermitian polynomial of order 1 It is a Hermitian polynomial of order 0. The total phase can be expressed as: For phase factor; k is the wave number ,in Let be the radius of curvature of the equiphase surface. ; The Gouy phase is defined as: ; Rayleigh length is defined as: ;because Hermitian polynomials have The beam has a real root and naturally splits into m+1 independent lobes in the cross-section; the Hermit-Gaussian beam has m+1 lobes originating from the same resonant cavity mode oscillation, the intensity of each lobe is gradient-distributed and spatially separated, and the power drift and pulse time fluctuation of the laser source are proportionally and synchronously superimposed on all lobes in a common-mode form. A beam shaping module is located downstream of the Hermit-Gaussian beam and is used to separate each lobe into m+1 parallel beams, with each beam having the same spot size and uniform intensity distribution. A nonlinear crystal aging module includes one or more sample testing units for placing nonlinear optical crystal samples to be tested. The module provides multiple simultaneously frequency-converted laser environments, converting the input fundamental frequency infrared laser to a visible or ultraviolet band, and providing identical and synchronized aging environment conditions for all nonlinear optical crystal samples. When there are multiple nonlinear optical crystal samples, multiple parallel beams illuminate the corresponding nonlinear optical crystal sample. When there is only one nonlinear optical crystal sample, and the sample is a large-aperture nonlinear optical crystal, multiple parallel beams illuminate at most m+1 different lateral positions of the sample. The detection and analysis module is used to simultaneously detect the output power and spectral characteristics of each beam, and to evaluate the aging characteristics and lifetime distribution of the nonlinear optical crystal sample based on the cancellation effect of common-mode interference in data processing.

[0010] According to the present invention, a nonlinear optical crystal homogeneous multipath parallel accelerated aging device is provided. The detection and analysis module performs perturbation cancellation based on the common-mode characteristics of homogeneous lasers. The specific data processing procedure is as follows: Let P be the output power of the k-th beam at time t. k (t), the initial incident power is I k(0), since all lobes share the same common mode origin, the light source wave is applied to all lobes in the same proportion δ(t): P k (t) = η k (t) · δ(t) · I k (0); Where, η k (t) represents the actual transmittance of the k-th crystal, and δ(t) represents the light source fluctuation factor. For any two beams i and j, calculate their power ratio: R ij (t) = P i (t) / P j (t) = [η i (t)·I i (0)] / [η j (t)·I j (0)]; Since δ(t) is canceled out, the ratio R ij (t) only reflects the relative aging state of the crystal and is not affected by fluctuations in the light source; If the initial intensity ratio α of each lobe is known... k And the initial incident power of each lobe satisfies I k (0)=α k ·I0, where I0 is the reference power, then the normalized transmittance can be calculated: T k (t) = P k (t) / (α k · P1(t) / α1) = η k (t) / η1(t); The parameters n and C of the inverse power law model are fitted using multi-point data.

[0011] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the peak intensity ratio of the m+1 lobes of the Hermitian-Gaussian beam is determined by the Hermitian polynomial, no attenuation optical elements are set between the lobes, and the proportional relationship of the peak intensity of each lobe constitutes the stress gradient of each parallel beam.

[0012] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the beam shaping module includes a collimating lens, a beam expander group and an aperture arranged sequentially; wherein, the collimating lens is used to convert the Hermit-Gaussian beam into collimated light; the beam expander group allows the individual independent lobes in the Hermit-Gaussian beam to naturally separate when propagating in space; and the aperture is used to limit the separated beams so that the spot size of each parallel beam is consistent and the light intensity is uniformly distributed.

[0013] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein each sample testing unit includes a testing chamber and an environmental control module. The nonlinear optical crystal sample is placed in the testing chamber, and the environmental control modules of each testing chamber operate synchronously to provide the same and synchronous aging environmental conditions for all sample areas. The environmental control module includes at least one of a temperature control unit, a humidity control unit, an atmosphere control unit, a stress control unit, and an auxiliary laser control unit.

[0014] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the temperature control unit is configured to control the temperature of the sample area to be adjustable within the range of -20℃ to 150℃; the humidity control unit is configured to control the relative humidity of the sample area to be adjustable within the range of 10% RH to 90% RH; the atmosphere control unit is configured to introduce nitrogen, oxygen, inert gas or mixed gas into the sample area; the stress control unit is configured to apply static or dynamic mechanical stress of 0~50 MPa to a specific crystal direction of the nonlinear optical crystal sample; the auxiliary laser control unit is configured to provide an ultraviolet laser source other than the main beam; and the environmental control modules of each sample testing unit are linked to ensure that all nonlinear optical crystal samples are under the same aging environment conditions.

[0015] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the detection and analysis module includes a beam splitter and functional devices. The beam splitter is disposed downstream of the optical path of the nonlinear crystal aging module, and the light reflected by the beam splitter enters the functional devices. The functional devices include at least one of a spectrometer, a power meter, or an image sensor.

[0016] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the detection and analysis module further includes a detection light source, which is used to generate three-dimensional structured light and apply it to the nonlinear optical crystal sample, and to determine whether there are defects inside the nonlinear optical crystal sample based on the received backlight signal.

[0017] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the detection and analysis module further includes an infrared thermal imager and an imaging module; wherein the infrared thermal imager is used to determine the potential damage location of the nonlinear optical crystal sample, and the imaging module is used to record the surface morphology changes of the nonlinear optical crystal sample.

[0018] According to the present invention, a nonlinear optical crystal homogeneous multi-path parallel accelerated aging device is provided, wherein the beam generation module includes a laser gain module, a cavity mirror element of the resonant cavity, a laser cavity mode selection element and a laser mode detection module; The laser gain module is used to achieve stable laser gain; the cavity mirror elements of the resonant cavity are selected with appropriate radii of curvature and output coupling rates to cooperate with the laser gain module to achieve efficient laser output; the laser cavity mode selection element selects the transverse mode within the laser resonant cavity in two directions, so that the fundamental transverse mode is output in one direction and the HGO mode is output in the other direction. m Transverse mode output; the laser mode detection module is used to observe the envelope of the output beam and adjust the angle of the cavity mirror element to introduce the detuning of the resonant cavity according to the observation results, while adjusting the position of the laser mode selection element until a high-purity Hermitian-Gaussian laser mode appears; the cavity mirror element and the laser cavity mode selection element realize differentiated control of the loss of different orders of cavity modes, thereby ensuring the high-purity output of one-dimensional high-order Hermitian-Gaussian laser beams of different orders.

[0019] This invention utilizes m+1 spatially separated lobes of the same high-order Hermitian-Gaussian eigenmode to form a multi-beam structure. Each lobe maintains synchronized power drift and pulse fluctuations, thus making the light source disturbance in the detection results appear as a common-mode term that can be eliminated through ratio calculations. The inherent peak intensity ratios of each lobe simultaneously constitute multiple stress level gradients, allowing the acquisition of multiple sets of degradation data under identical and synchronized aging conditions. Therefore, without altering the physical aging mechanism of individual devices, the device can reduce the benchmark deviation caused by repeatedly building independent laser links, improve batch screening efficiency, and enhance the comparability and reliability of lifetime model parameter fitting. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is one of the structural schematic diagrams of the nonlinear optical crystal homogeneous multi-path parallel accelerated aging device provided by the present invention.

[0022] Figure 2 This is the second schematic diagram of the nonlinear optical crystal homogeneous multi-path parallel accelerated aging device provided by the present invention.

[0023] Figure label: 1. Beam generation module; 2. Beam shaping module; 3. Nonlinear crystal aging module; 4. Detection and analysis module. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] like Figure 1 As shown, the nonlinear optical crystal homogeneous multi-path parallel accelerated aging device of this invention includes: Beam generation module 1 generates a Hermitian-Gaussian beam based on a single laser oscillation / amplification link. The Hermitian-Gaussian beam adopts a one-dimensional higher-order mode. The order m is not less than 3; among them, the Hermit-Gaussian beam has multiple lobes with gradient intensity distribution and spatial separation. For distribution along the y-axis The normalized amplitude distribution of the optical field. It can be represented as: ; Where A is the normalized optical field amplitude coefficient. , w o and w ( z ) are respectively z = 0 and z Positional fundamental model ( HG 00 Waist radius, molecule Normalization coefficient (make) ), defined as: ; Let x and y be the transverse Gaussian distribution envelope of the light field amplitude, and z be the transverse coordinates of the light field. for Hermitian polynomial of order 1 It is a Hermitian polynomial of order 0. The total phase can be expressed as: For phase factor; k is the wave number ,in Let be the radius of curvature of the equiphase surface. ; The Gouy phase is defined as: ; Rayleigh length is defined as: ;because Hermitian polynomials have The beam has a real root and naturally splits into m+1 independent lobes in the cross-section; the Hermit-Gaussian beam has m+1 lobes originating from the same resonant cavity mode oscillation, the intensity of each lobe is gradient-distributed and spatially separated, and the power drift and pulse time fluctuation of the laser source are proportionally and synchronously superimposed on all lobes in a common-mode form. The beam shaping module 2 is located downstream of the Hermit-Gaussian beam and is used to separate each lobe into m+1 parallel beams. The beam spot size of each beam is consistent and the intensity distribution is uniform. The nonlinear crystal aging module 3 includes one or more sample testing units, which are used to place the nonlinear optical crystal sample to be tested. The nonlinear crystal aging module provides multiple simultaneously frequency-converted laser irradiation environments, converting the input fundamental frequency infrared laser to change its wavelength from the infrared band to the visible or ultraviolet band, and providing the same and synchronous aging environment conditions for all nonlinear optical crystal samples. When there are multiple nonlinear optical crystal samples, multiple parallel beams are respectively irradiated to the corresponding nonlinear optical crystal samples. When there is only one nonlinear optical crystal sample, the nonlinear optical crystal sample is a large-aperture nonlinear optical crystal sample, and multiple parallel beams are respectively irradiated to at most m+1 different lateral positions of the nonlinear optical crystal sample. The detection and analysis module 4 is used to simultaneously detect the output power and spectral characteristics of each beam, and to evaluate the aging characteristics and lifetime distribution of the nonlinear optical crystal sample based on the cancellation effect of common-mode interference in data processing.

[0026] The nonlinear optical crystals used as test samples mainly include borate crystals (such as LBO, BBO, and CLBO) and potassium dihydrogen phosphate crystals (such as KDP and DKDP). Furthermore, this device has good versatility and can be adapted to other types of nonlinear optical materials according to experimental requirements, specifically including: deep ultraviolet crystals, such as potassium fluoroborate (KBBF) and rubidium fluoroborate (RBBF); near-infrared and mid-far-infrared crystals, such as lithium niobate (LiNbO3), zinc germanium phosphate (ZGP), and gallium selenide (GaSe); and quasi-phase-matched devices, such as periodically polarized lithium niobate (PPLN) and periodically polarized lithium tantalate (PPLT).

[0027] In this embodiment, four co-source lobes are formed using the HG0,3 mode. After being expanded fivefold by the beam shaping module 2 and trimmed by a 3 mm aperture, four parallel beams with identical spot sizes are formed. These four beams illuminate the nonlinear optical crystal samples in four sample testing units, or illuminate four lateral positions of the same large-aperture sample. The environmental control modules of each testing unit operate in tandem, synchronously conducting aging tests under the example conditions of 25°C and 30% RH. The detection and analysis module 4 collects the output power and spectral data of each beam at the same time reference and cancels common-mode fluctuations of the co-source light source by normalizing the ratio.

[0028] In an optional embodiment, the detection and analysis module performs perturbation cancellation based on the common-mode characteristics of the same-source lasers. The specific data processing procedure is as follows: Let P be the output power of the k-th beam at time t. k (t), the initial incident power is I k (0), since all lobes share the same common mode origin, the light source wave is applied to all lobes in the same proportion δ(t): P k (t) = η k (t) · δ(t) · I k (0); Where, η k (t) represents the actual transmittance of the k-th crystal (including aging effect), and δ(t) represents the light source fluctuation factor. For any two beams i and j, calculate their power ratio: R ij (t) = P i (t) / P j (t) = [η i (t)·I i (0)] / [η j (t)·I j (0)]; Since δ(t) is canceled out, the ratio R ij (t) only reflects the relative aging state of the crystal and is not affected by fluctuations in the light source; If the initial intensity ratio α of each lobe is known... k (Determined by Hermitian polynomials), and the initial incident power of each lobe satisfies I k (0)=α k ·I0, where I0 is the reference power, then the normalized transmittance can be calculated: T k (t) = P k (t) / (α k · P1(t) / α1) = η k(t) / η1(t); The parameters n and C of the inverse power law model are fitted using multi-point data.

[0029] In this embodiment, the peak intensity ratio of the m+1 lobes of the Hermitian-Gaussian beam is determined by the Hermitian polynomial. No attenuation optical elements are set between the lobes, and the ratio of the peak intensity of each lobe constitutes the stress gradient of each parallel beam.

[0030] In optional embodiments, such as Figure 1 As shown, the beam shaping module 2 includes a collimating lens, a beam expander group, and an aperture arranged in sequence; wherein, the collimating lens is used to convert the Hermetic-Gaussian beam into collimated light; the beam expander group allows the individual lobes in the Hermetic-Gaussian beam to naturally separate when propagating in space; the aperture is used to limit the individual beams after separation so that the spot size of each parallel beam is consistent and the light intensity is uniformly distributed.

[0031] In this embodiment, the beam shaping module 2 is located downstream of the beam generation module 1 in the optical path, and mainly consists of a collimating lens, a beam expander group, and an aperture arranged sequentially along the optical path. The high-order Hermitian-Gaussian beam from the front-end beam generation module 1 often has a certain divergence angle. The collimating lens converts this diverging fundamental frequency beam into a collimated beam that propagates in parallel, ensuring the controllability of the subsequent beam spot size. Although the individual laser lobes of the high-order Hermitian-Gaussian beam are separated in cross-section, their spacing is relatively small. By amplifying the beam through the beam expander group, the center-to-center distance between the individual laser lobes is proportionally increased, thereby achieving natural separation of the lobes during spatial propagation and avoiding diffraction effects or losses caused by physically cutting the lenses. The aperture is located at the output end of the beam expander group. Since the edges of the individual lobes of the high-order HG beam may have low-intensity diffraction rings or transition regions, the aperture is used to trim the separated beam. By adjusting the aperture, stray light and non-uniform parts at the edges of each beam are filtered out, ensuring that each parallel beam in the final output (corresponding to each lobe of the original HG beam) has a consistent spot diameter and a relatively flat and uniform light intensity distribution. Subsequently, these high-quality parallel beams are incident on the corresponding nonlinear optical crystal sample or at most m+1 different lateral positions of the nonlinear optical crystal sample in the subsequent nonlinear crystal aging module 3.

[0032] In optional embodiments, such as Figure 1 As shown, each sample testing unit includes a testing chamber and an environmental control module. The nonlinear optical crystal sample is placed in the testing chamber. The environmental control modules of each testing chamber operate synchronously to provide the same and synchronized aging environment conditions for all sample areas. The environmental control module includes at least one of a temperature control unit, a humidity control unit, an atmosphere control unit, a stress control unit, and an auxiliary laser control unit.

[0033] It is understandable that when there is only one nonlinear optical crystal sample, there is only one sample testing unit; when there are multiple nonlinear optical crystal samples, there are multiple sample testing units, with each nonlinear optical crystal sample placed in its corresponding sample testing unit.

[0034] In this embodiment, the nonlinear crystal aging module 3 is designed as an array structure, including, for example, four independent sample testing units 3A, 3B, 3C, and 3D (the number can be adjusted according to the number of lobes of the HG beam, such as 4 units corresponding to HG0,3 mode). These four units are arranged side by side in physical space, and are respectively aligned with the four parallel beams output by the aforementioned beam shaping module 2.

[0035] It should be noted that each sample testing unit (taking 3A as an example) includes an independent testing chamber and an environmental control module. The testing chamber is a sealed cavity with entrance and exit windows at its front and rear ends, respectively. High-transmittance quartz glass can be installed on the windows, coated with an anti-reflection film corresponding to the wavelength to minimize window loss. Additionally, a sample holder is installed inside the cavity. The sample holder can be a multi-axis precision adjustment frame used to mount and fine-tune the angle of the nonlinear optical crystal under test to meet phase matching conditions.

[0036] In practical applications, the temperature control unit is configured to control the sample area temperature within the range of -20℃ to 150℃; the humidity control unit is configured to control the relative humidity of the sample area within the range of 10% RH to 90% RH; the atmosphere control unit is configured to introduce nitrogen, oxygen, inert gas, or a mixture of gases into the sample area; the stress control unit is configured to apply static or dynamic mechanical stress of 0~50 MPa to a specific crystal orientation of the nonlinear optical crystal sample; the auxiliary laser control unit is configured to provide an ultraviolet laser source other than the main beam; and the environmental control modules of each sample testing unit are linked to ensure that all nonlinear optical crystal samples are under the same aging environment conditions.

[0037] Specifically, the temperature control unit employs a closed-loop temperature control system, primarily composed of heating / cooling actuators (such as thermoelectric coolers (TEC) or precision resistance heating wires), high-precision temperature sensors (such as platinum resistance thermometers (Pt100), and a PID temperature controller. This system can precisely control the temperature of the sample area within the range of -20℃ to 150℃, with a temperature control accuracy better than ±0.5℃. Through this unit, the device can simulate high-temperature conditions to accelerate the thermal aging process of crystals, or execute high-low temperature alternating programs to study the effects of temperature cycling on the physical properties of crystals and the stability of the film.

[0038] The humidity control unit is equipped with a gas mixing and regulation system, which precisely adjusts the mixing ratio of the humidifying gas generated by the atomizing humidifier with the dry background gas (such as high-purity nitrogen or dry air) to achieve continuous adjustment of the relative humidity within the test chamber from 10%RH to 90%RH. This function is used to simulate different humidity environments, focusing on the atomization phenomenon on the surface of nonlinear optical crystals caused by water vapor adsorption and the bulk damage mechanism caused by deliquescence.

[0039] The atmosphere control unit is based on a sealed or micro-flow chamber design within the test chamber. This unit includes inlet and outlet control lines, supporting the introduction of specific types of gases into the chamber, including but not limited to nitrogen, oxygen, inert gases, or mixtures of gases in specific proportions. This unit is used to construct specific gaseous chemical environments to investigate the photochemical aging behavior (such as ozone corrosion, organic matter deposition, etc.) of nonlinear optical crystals under laser irradiation and surrounding gases.

[0040] The stress control unit is integrated into the sample fixture structure and includes a micro-force loading mechanism (such as a piezoelectric ceramic actuator or a mechanical screw loading device). This mechanism can apply static stress or dynamic alternating stress of 0–50 MPa along a specific lattice direction of the crystal. Through this unit, the mechanical stress state of the crystal during installation or operation can be simulated, thereby studying the crystal damage and fracture mechanism under the synergistic effect of the mechanical stress field and the strong laser field.

[0041] In addition to the Hermit-Gaussian beam used for the main test, the platform is also equipped with an independent auxiliary optical path interface, which can accommodate an additional ultraviolet laser source. The wavelength, power, energy, and repetition frequency of this auxiliary light source can all be adjusted according to the accelerated aging requirements. This unit is used to introduce additional photon energy to simulate extreme aging conditions such as multi-band laser irradiation and photothermal coupling, thereby enabling a comprehensive evaluation of crystal lifetime under complex operating conditions.

[0042] As mentioned above, each test chamber is independently equipped with an environmental control module, and operators can flexibly configure and combine the various functional units according to experimental needs.

[0043] In optional embodiments, such as Figure 1 As shown, the detection and analysis module 4 includes a beam splitter and functional devices. The beam splitter is positioned downstream of the optical path of the nonlinear crystal aging module, and the light reflected from the beam splitter enters the functional devices. The functional devices include at least one of a spectrometer, a power meter, or an image sensor. The image sensor can be a CCD or a CMOS sensor.

[0044] In this embodiment, the detection and analysis module 4 is located downstream of the optical path of each test unit in the nonlinear crystal aging module. For each beam emitted from the nonlinear optical crystal sample, the detection and analysis module includes a beam splitter and a functional device.

[0045] Specifically, the beam splitter is positioned at a 45° angle in the main optical path, reflecting a small portion of the emitted beam's energy as a sample beam to the side, while most of the light energy is transmitted and absorbed by a light collector or blocker to ensure safety. When monitoring for color centers or coating damage in the crystal, a fiber optic spectrometer is installed along the beam splitter's reflection path. The sample beam is coupled into the spectrometer via fiber optic cable, and the spectral curve of the emitted light is recorded in real time. The degree of crystal aging is determined by observing changes in absorption peaks at specific wavelengths. When evaluating the crystal's conversion efficiency or transmittance, the spectrometer is replaced with a high-precision laser power meter. The power meter probe receives the sample beam and records the power value in real time. By comparing the incident light power (known) with the emitted light power, the transmittance and conversion efficiency degradation curves of the crystal during the aging process are determined.

[0046] In practical applications, the detection and analysis module also includes a detection light source, which is used to generate three-dimensional structured light and apply it to the nonlinear optical crystal sample, and to determine whether there are defects inside the nonlinear optical crystal sample based on the received return light signal.

[0047] As an example, the detection light source employs a structured light projector based on DLP (Digital Light Processing) technology. This light source does not use high-energy lasers, but instead emits visible light (such as blue light at 450nm) with wavelengths that do not damage the crystal. The projector generates an encoded three-dimensional structured light pattern. The structured light pattern emitted by the detection light source is projected through a collimating lens group and focused onto the interior of the nonlinear optical crystal sample under test. Since the crystal is a transparent medium, the light beam normally transmits. However, if there are microcracks, inclusions, or laser-induced damage points inside the crystal due to aging, these defects can cause abrupt changes in the refractive index of the light, resulting in scattering or reflection signals. A high-resolution CMOS camera is positioned at a predetermined angle (e.g., 30°–45°) to the detection light source. The camera synchronously acquires modulated images (i.e., backlight signals) of the crystal in response to the structured light pattern. When the structured light sweeps across defect points inside the crystal, the projected fringes deform or shift in phase. These backlight signals are processed using a phase unwrapping algorithm to calculate the phase difference, thereby reconstructing the three-dimensional spatial coordinates and volume of the defects inside the crystal.

[0048] In practical applications, the detection and analysis module also includes an infrared thermal imager and an imaging module; the infrared thermal imager is used to determine the potential damage location of the nonlinear optical crystal sample, and the imaging module is used to record the surface morphology changes of the nonlinear optical crystal sample.

[0049] As an example, a long-wave infrared thermal imager is used, with its lens angled towards the nonlinear optical crystal sample in the test chamber through a window with high infrared transmittance. During laser irradiation, if impurities, color centers, or minor damage exist within the crystal, the absorption coefficient in that area will increase, leading to an abnormal increase in local temperature and the formation of a "hot spot." The infrared thermal imager acquires a real-time thermal distribution cloud map of the crystal, and by capturing areas of abnormal temperature rise (such as areas where the local temperature rise exceeds the ambient temperature or the set temperature control value of 5°C), it can locate potential damage locations in advance, even if the damage has not yet developed into visible destruction.

[0050] The imaging module consists of a high-resolution industrial camera (CCD or CMOS sensor) and a long-working-distance microscope lens, equipped with a ring-shaped LED illumination source. The module is mounted at a certain angle (e.g., 30 degrees) to the laser optical axis, focusing on the light-transmitting surface of the crystal. The imaging module captures high-resolution images of the crystal surface at preset time intervals (e.g., once per hour). Combined with image processing algorithms, the system automatically compares images from different times to identify morphological changes occurring on the surface, such as the diffusion of the atomized area, the appearance of laser-induced ablation pits, or the growth of microcracks. It provides intuitive visual evidence for recording the morphological evolution during the aging process.

[0051] In optional embodiments, such as Figure 1 As shown, the beam generation module 1 includes a laser gain module, a cavity mirror element of the resonant cavity, a laser cavity mode selection element, and a laser mode detection module; The laser gain module is used to achieve stable laser gain; the cavity mirror elements of the resonant cavity are selected with appropriate radii of curvature and output coupling rates to cooperate with the laser gain module to achieve efficient laser output; the laser cavity mode selection element selects the transverse mode within the laser resonant cavity in two directions, so that the fundamental transverse mode is output in one direction and the HG0 mode is output in the other direction. m Transverse mode output; the laser mode detection module is used to observe the envelope of the output beam and adjust the angle of the cavity mirror element to introduce the detuning of the resonant cavity based on the observation results. At the same time, the position of the laser mode selection element is adjusted until a high-purity Hermitian-Gaussian laser mode appears. The cavity mirror element and the laser cavity mode selection element realize differentiated control of the loss of different orders of cavity modes, thereby ensuring the high-purity output of one-dimensional high-order Hermitian-Gaussian laser beams of different orders.

[0052] This embodiment of the device optimizes the design of the laser resonator and combines the control of the intracavity mode selection element and angular detuning to differentially modulate the intracavity mode loss of different orders, thereby generating high-purity one-dimensional Hermitian-Gaussian laser beams of different orders. This method achieves high-purity one-dimensional high-order Hermitian-Gaussian laser output, providing a high-quality excitation source foundation for the co-source multi-path parallel accelerated aging test of this device.

[0053] In practical applications, beam generation module 1 also includes a Q-switching module to achieve short-pulse HG0. m Laser beam output.

[0054] In addition, the laser gain module includes at least one doped ion selected from Nd, Yb, Tm, Ho, and Er, and at least one laser matrix selected from YAG, YVO4, and YLF, in combination with at least one of Yb:YAG, Tm:YVO4, and Nd:YLF. As an example, the laser gain module uses a large-area pumped Nd:YAG slab crystal, which has a large mode field characteristic in the width direction and can output fundamental frequency light with a wavelength of 1064 nm.

[0055] It is particularly noteworthy that the beam generation module 1 is highly adjustable. By changing different gain media (e.g., switching from Nd:YAG to Yb:YAG or Nd:YVO4) and adjusting the aperture and position of the mode selection aperture, this module can flexibly change the wavelength, power, single-pulse energy, repetition frequency, and order of the Hermit-Gaussian mode of the output beam. This multi-parameter adjustable design allows the device to be precisely adapted to different types of nonlinear optical crystals (including but not limited to LBO, BBO, KDP, CLBO, etc.), meeting the differentiated experimental needs of targeted studies on the effects of various crystal aging processes on fundamental frequency optical parameters (such as wavelength sensitivity, power density dependence, etc.).

[0056] The experimental steps of the nonlinear optical crystal homogeneous multi-path parallel accelerated aging device in this embodiment include the following steps: a) Generate a one-dimensional higher-order Hermitian-Gaussian beam; b) Beam expansion and beam splitting: The beam is expanded and its natural lobe characteristics are used to split it into multiple parallel beams; c) Synchronous irradiation: The multi-parallel beams are guided to at most m+1 different lateral positions of a single nonlinear optical crystal sample or multiple nonlinear optical crystal samples for synchronous irradiation; d) Real-time monitoring: During irradiation, ensure that all nonlinear optical crystal samples are under the same aging environment conditions, and monitor the spectrum and power of the emitted light of each sample in real time, as well as the morphology of the crystal surface and the state of internal defects. e) Assessment and prediction: Based on one or more failure criteria, such as the appearance of damage points, significant changes in the spectrum, or a decrease in frequency conversion efficiency or transmittance, comprehensively assess the aging behavior of the nonlinear optical crystal and predict its service life.

[0057] To facilitate understanding, the following section will explain the mathematical principle of multi-path parallel equivalent acceleration, which is to transform the statistical problem of aging test time dimension into an estimation problem of spatial dimension.

[0058] 1. Basic Definition – Single Sample Serial Test Model First, the traditional accelerated aging test model is defined.

[0059] Objective: To evaluate the lifetime of a crystal sample under real-world operating conditions. .

[0060] Method: At a power density much higher than the actual power density stress level ( The test will be conducted below.

[0061] Key model: Inverse power law model, which is a classic model for accelerated life testing.

[0062] Crystal lifetime With applied light intensity stress of The power is inversely proportional: ; in, These are constants related to crystal materials, environment, etc. It is the aging acceleration index.

[0063] Serial test: Test one after another One sample.

[0064] Total time ,in Is a single sample under accelerated stress? The time required for failure. This process is time-consuming.

[0065] 2. Core Principle – Equivalence Proof of Parallel Testing The embodiments of the present invention no longer simply change the stress intensity on the time axis, but instead create multiple stress level gradients with a fixed proportional relationship in space.

[0066] 2.1 Constructing the spatial stress gradient One-dimensional higher-order Hermitian-Gaussian beam Peak intensity of each lobe They are not equal, but rather determined by Hermitian polynomials. The extreme values ​​are determined by the peak values. These peak intensities exhibit a proportional relationship determined by Hermitian polynomials. Wherein, I... k This represents the peak light intensity of the k-th lobe, compared to the aforementioned initial incident power I. k(0) Proportional; when the area of ​​each light spot is the same, the two use the same proportional coefficient.

[0067] Let the intensity of the first lobe (with the highest peak value) be... Then the first The intensity of each lobe is: ; in, It is a precise constant that can be calculated theoretically.

[0068] 2.2 Establishing a parallel lifetime model we will A crystal sample (or a large sample) Each region was placed at these precisely known stress levels. Then, synchronous aging is carried out.

[0069] According to the inverse power law model, the first Failure time of each sample Should meet: ; Or write: ; 2.3 The Core of Mathematical Equivalence This invention does not require direct measurement of crystal lifetime under target operating conditions, but instead utilizes a single parallel experiment to simultaneously obtain the lifetime at different stress levels. k The sample failure time L k (or performance degradation rate) data, and then the data points (I k ,L k Substituting the values ​​into the inverse power-law model, the model parameters are determined through linear fitting in a double logarithmic coordinate system. The slope of the fitted line corresponds to the aging acceleration index n, and the intercept corresponds to the material constant C.

[0070] get and Then, the light intensity at any target can be extrapolated and calculated. The actual lifespan : ; A single spatial multi-point parallel test is mathematically equivalent to multiple time-sequential tests, which can simultaneously obtain multiple data points on the acceleration curve, thereby achieving equivalent acceleration.

[0071] Unlike traditional serial methods that measure point by point, this invention utilizes the inherent light intensity ratio of each lobe to construct a multi-stress level synchronous test.

[0072] By comparing the failure time or performance degradation rate of samples under different stress levels, accelerated aging curves can be obtained and lifetime model parameters can be determined in a single experiment.

[0073] The mathematical expression is: mapping the space of a single-stress repeated experiment on the time axis to a multi-stress single experiment in space.

[0074] As can be seen from the above, the mathematical principle of parallel acceleration is as follows: the "equivalent acceleration" described in this invention is based on the inverse power-law model in accelerated lifetime testing. Let the nonlinear optical crystal be subjected to light intensity stress... Lifespan satisfy ,in It is a constant. The aging acceleration index. (Utilizing...) Precise intensity ratio of each lobe of the light beam By simultaneously aging crystal samples placed under different lobes, a set of lifetime data can be obtained. .Depend on It can be seen that in a double logarithmic coordinate system, the point set The relationship is linear. By fitting this line through a single parallel experiment, the relationship can be determined. and The specific value is used to extrapolate and calculate the light intensity of any target. Crystal lifetime This means that by conducting a single multi-stress level test in the spatial dimension, multiple serial single-stress level tests in the temporal dimension are equivalently achieved, fundamentally doubling the test throughput.

[0075] This embodiment cleverly utilizes the inherent physical properties of high-order Hermitian-Gaussian beams. Its optical field itself contains multiple spatially separated laser lobes, which can be combined into multiple parallel beams through simple beam expansion. Crucially, all lobes originate from the same intrinsic mode oscillation within the same laser resonant cavity, meaning their pulse duration, energy fluctuations, and other characteristics are completely synchronized. Therefore, any fluctuations in the laser source itself (such as power drift) are equally applied to all test points in the form of common-mode homogeneity. During data analysis, especially when calculating the relative aging rates or lifetime ratios between different samples, this common-mode interference is mathematically automatically canceled out. Thus, this invention fundamentally ensures a high degree of consistency in the reference between the beams, eliminating the unavoidable source instability errors in traditional beam splitting schemes, and laying a solid foundation for obtaining highly reliable and comparable experimental data.

[0076] It boasts good versatility, capable of accommodating nonlinear optical crystal samples of varying sizes and shapes. Simultaneously, the integrated environmental control module offers a wide dynamic range adjustment capability, covering a broad parameter range. This design flexibility greatly expands the application scenarios of this device, enabling it to perform accelerated aging tests under conventional conditions as well as simulate extreme conditions (such as high and low temperature shocks, highly corrosive atmospheres) or complex stress environments in specific application scenarios. Therefore, it effectively overcomes the limitations of existing dedicated experimental devices, which are characterized by single functionality and narrow applicability, providing a more comprehensive experimental platform for crystal reliability research.

[0077] Example 1: LBO crystal 343 nm third harmonic aging test (e.g.) Figure 1 (As shown) Laser source parameters: Yb:YAG, 1030nm, HG0,3 mode; The first slab crystal is used for laser generation, and the other slab crystal is used for laser amplification. Two LBO crystals, placed one in front of the other, are used for frequency doubling (generating 515 nm green light) and summing (generating 343 nm ultraviolet light), respectively. Beam shaping parameters: beam expansion factor of 5x, aperture diameter of 3 mm; The crystal parameters are as follows: Frequency doubling crystal parameters: A Class I LBO crystal with critical phase matching is used, with a cutting angle θ = 90°. = 13.6°, crystal size is 5mm×5mm×20mm, crystal temperature control is room temperature; Sum-frequency crystal parameters: A type II LBO crystal with critical phase matching is used, with a cutting angle θ = 50.5°. = 90°, crystal size is 5mm×5mm×20mm, crystal temperature control is room temperature; Environmental parameters: Temperature set to 25℃, relative humidity set to 30% RH; Aging data acquisition: The transmittance and frequency conversion efficiency of each channel are continuously recorded at a sampling interval of 1 hour to form a degradation curve that changes over time.

[0078] Data processing: The normalized transmittance fluctuation amplitude before and after common-mode cancellation is calculated separately to quantify the suppression effect of light source fluctuation.

[0079] Example 2: BBO crystal 266nm fourth harmonic aging test (e.g.) Figure 2 (As shown) Laser source parameters: Nd:YAG, 1064nm, HG 0,7 model; The first slab crystal is used for laser generation, and the other slab crystal is used for laser amplification. After being amplified, the single-path laser enters the accelerated aging device, where it is frequency-doubled by a single LBO crystal. The multi-lobe spatial structure of the high-order HG beam is maintained during the frequency doubling process, forming multiple 532 nm frequency-doubled spots corresponding to the fundamental frequency lobe distribution. Subsequently, it is quadrupled by two symmetrically placed BBO crystals. The symmetrical arrangement of the two BBO crystals is used to compensate for the birefringence walk-off effect and improve the consistency of the quadrupling efficiency of each lobe. Frequency doubling crystal parameters: A non-critical phase-matched Type I LBO crystal is used, with a cutting angle θ = 90°. = 0°, crystal size is 5mm×5mm×25mm, crystal temperature control is 148.5℃; Fourth harmonic crystal parameters: A Class I BBO crystal with critical phase matching is used, with a cutting angle θ = 47.6°. = 0°, crystal size is 5mm×5mm×7mm, crystal temperature control is room temperature; Aging data acquisition: Record and compare the differences in aging rates under different stress levels corresponding to different lobes.

[0080] Model Fitting: Fit an inverse power-law model based on stress levels and life data, and report the model parameters n, C, and coefficient of determination R. 2 .

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A nonlinear optical crystal homogeneous multi-path parallel accelerated aging device, characterized in that, include: The beam generation module generates a Hermitian-Gaussian beam based on a single laser oscillation / amplification link. The Hermitian-Gaussian beam employs a one-dimensional higher-order mode. The order m is not less than 3; wherein the Hermit-Gaussian beam has multiple lobes with gradient intensity distribution and spatial separation. For distribution along the y-axis The normalized amplitude distribution of the optical field. It can be represented as: ； Where A is the normalized optical field amplitude coefficient. , w o and w ( z ) are respectively z = 0 and z Positional fundamental model ( HG 00 Waist radius, molecule Normalization coefficient (make) ), defined as: ; Let x and y be the transverse Gaussian distribution envelope of the light field amplitude, and z be the transverse coordinates of the light field. for Hermitian polynomial of order 1 It is a Hermitian polynomial of order 0. The total phase can be expressed as: For phase factor; k is the wave number ,in Let be the radius of curvature of the equiphase surface. ; The Gouy phase is defined as: ; Rayleigh length is defined as: ;because Hermitian polynomials have The beam has a real root and naturally splits into m+1 independent lobes in the cross-section; the Hermit-Gaussian beam has m+1 lobes originating from the same resonant cavity mode oscillation, the intensity of each lobe is gradient-distributed and spatially separated, and the power drift and pulse time fluctuation of the laser source are proportionally and synchronously superimposed on all lobes in a common-mode form. A beam shaping module is located downstream of the Hermit-Gaussian beam and is used to separate each lobe into m+1 parallel beams, with each beam having the same spot size and uniform intensity distribution. A nonlinear crystal aging module includes one or more sample testing units for placing nonlinear optical crystal samples to be tested. The module provides multiple simultaneously frequency-converted laser environments, converting the input fundamental frequency infrared laser to a visible or ultraviolet band, and providing identical and synchronized aging environment conditions for all nonlinear optical crystal samples. When there are multiple nonlinear optical crystal samples, multiple parallel beams illuminate the corresponding nonlinear optical crystal sample. When there is only one nonlinear optical crystal sample, and the sample is a large-aperture nonlinear optical crystal, multiple parallel beams illuminate at most m+1 different lateral positions of the sample. The detection and analysis module is used to simultaneously detect the output power and spectral characteristics of each beam, and to evaluate the aging characteristics and lifetime distribution of the nonlinear optical crystal sample based on the cancellation effect of common-mode interference in data processing.

2. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 1, characterized in that, The detection and analysis module performs perturbation cancellation based on the common-mode property of the same-source laser. The specific data processing procedure is as follows: Let P be the output power of the k-th beam at time t. k (t), the initial incident power is I k (0), since all lobes share the same common mode origin, the light source wave is applied to all lobes in the same proportion δ(t): P k (t) = n k (t) δ(t) I k (0); Where, η k (t) represents the actual transmittance of the k-th crystal, and δ(t) represents the light source fluctuation factor. For any two beams i and j, calculate their power ratio: R ij (t) = P i (t) / P j (t) = [η i (t)·I i (0)] / [η j (t)·I j (0)]; Since δ(t) is canceled out, the ratio R ij (t) only reflects the relative aging state of the crystal and is not affected by fluctuations in the light source; If the initial intensity ratio α of each lobe is known... k And the initial incident power of each lobe satisfies I k (0)=α k ·I0, where I0 is the reference power, then the normalized transmittance can be calculated: T k (t) = P k (t) / (α k · P1(t) / α1) = η k (t) / η1(t); The parameters n and C of the inverse power law model are fitted using multi-point data.

3. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 1, characterized in that, The peak intensity ratio of the m+1 lobes of the Hermitian-Gaussian beam is determined by the Hermitian polynomial. No attenuation optical elements are set between the lobes, and the ratio of the peak intensity of each lobe constitutes the stress gradient of each parallel beam.

4. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 1, characterized in that, The beam shaping module includes a collimating lens, a beam expander group, and an aperture arranged in sequence; wherein, the collimating lens is used to convert the Hermetic-Gaussian beam into collimated light; the beam expander group allows the individual lobes in the Hermetic-Gaussian beam to naturally separate as they propagate in space; the aperture is used to limit the separated beams so that the spot size of each parallel beam is consistent and the light intensity is uniformly distributed.

5. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 1, characterized in that, Each of the sample testing units includes a testing chamber and an environmental control module. The nonlinear optical crystal sample is placed in the testing chamber. The environmental control modules of each testing chamber operate synchronously to provide the same and synchronized aging environment conditions for all sample areas. The environmental control module includes at least one of a temperature control unit, a humidity control unit, an atmosphere control unit, a stress control unit, and an auxiliary laser control unit.

6. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 5, characterized in that, The temperature control unit is configured to control the sample area temperature within the range of -20℃ to 150℃; the humidity control unit is configured to control the relative humidity of the sample area within the range of 10% RH to 90% RH; the atmosphere control unit is configured to introduce nitrogen, oxygen, inert gas, or a mixture of gases into the sample area; the stress control unit is configured to apply static or dynamic mechanical stress of 0~50 MPa to a specific crystal orientation of the nonlinear optical crystal sample; the auxiliary laser control unit is configured to provide an ultraviolet laser source other than the main beam; the environmental control modules of each sample testing unit are linked to ensure that all nonlinear optical crystal samples are under the same aging environment conditions.

7. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 1, characterized in that, The detection and analysis module includes a beam splitter and functional devices. The beam splitter is located downstream of the optical path of the nonlinear crystal aging module, and the light reflected by the beam splitter enters the functional devices. The functional devices include at least one of a spectrometer, a power meter, or an image sensor.

8. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 7, characterized in that, The detection and analysis module also includes a detection light source, which is used to generate three-dimensional structured light and apply it to the nonlinear optical crystal sample, and to determine whether there are defects inside the nonlinear optical crystal sample based on the received backlight signal.

9. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging device according to claim 7, characterized in that, The detection and analysis module further includes an infrared thermal imager and an imaging module; wherein, the infrared thermal imager is used to determine the potential damage location of the nonlinear optical crystal sample, and the imaging module is used to record the surface morphology changes of the nonlinear optical crystal sample.

10. The nonlinear optical crystal homogeneous multi-path parallel accelerated aging apparatus according to any one of claims 1 to 9, characterized in that, The beam generation module includes a laser gain module, a cavity mirror element of the resonant cavity, a laser cavity mode selection element, and a laser mode detection module. The laser gain module is used to achieve stable laser gain; the cavity mirror elements of the resonant cavity are selected with appropriate radii of curvature and output coupling rates to cooperate with the laser gain module to achieve efficient laser output; the laser cavity mode selection element selects the transverse mode within the laser resonant cavity in two directions, so that the fundamental transverse mode is output in one direction and the HGO mode is output in the other direction. m Transverse mode output; the laser mode detection module is used to observe the envelope of the output beam and adjust the angle of the cavity mirror element to introduce the detuning of the resonant cavity according to the observation results, while adjusting the position of the laser mode selection element until a high-purity Hermitian-Gaussian laser mode appears; the cavity mirror element and the laser cavity mode selection element realize differentiated control of the loss of different orders of cavity modes, thereby ensuring the high-purity output of one-dimensional high-order Hermitian-Gaussian laser beams of different orders.

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