Method for predicting damage evolution of optical element based on laser irradiation

Abstract

The invention relates to the technical field of optical elements, in particular to a method for predicting damage evolution of an optical element based on laser irradiation, which comprises the following steps: firstly, acquiring physical parameters (oxygen-silica ratio, transmissivity and absorption coefficient) and laser irradiation parameters (wavelength, energy density and repetition frequency) of the optical element; mapping the relationship between the environmental parameters and the damage threshold; constructing an oxygen-silica ratio-transmissivity-damage threshold correlation model, and analyzing evolution of physical parameters along with laser emission; the method comprises the following steps: establishing a heat-light-force multi-physics field coupling model, exploring a damage mechanism, finally predicting damage threshold evolution of the optical element after irradiation of different lasers through the models, obtaining a damage threshold change trend curve and a critical damage point, and establishing a damage prediction model based on physical parameters. Therefore, the damage evolution of the optical element is predicted in advance, the experimental period is shortened, and the evaluation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical elements, and in particular to a method for predicting the damage evolution of optical elements based on laser irradiation, which can be applied to damage prediction and life assessment of optical elements in high-power laser systems. Background Art

[0002] The problem of laser damage to fused quartz in a vacuum environment has always been one of the key issues restricting its application performance. In a vacuum environment, the ability of fused quartz to resist laser damage decreases, and the damage threshold is lower than that in the atmospheric environment, which leads to further expansion of the damage under subsequent laser irradiation, thereby increasing the operating cost and utilization efficiency of the system.

[0003] The study found that this change is mainly attributed to the enhancement of surface and internal defects of fused quartz in a vacuum environment and the change of heat transfer mode. Microscopically, when fused quartz is placed in a vacuum environment, ultraviolet laser irradiation will cause it to have induced defects such as ODCs and NBOHC, resulting in a substoichiometric ratio of the material (SiO x )x<2, studies have shown that the higher the laser flux, the more irradiation times, and the lower the oxygen-silicon ratio, the faster the appearance of oxygen defects. Since oxygen defects have a strong absorption effect on lasers, the laser damage threshold is reduced. Macroscopically, due to the extremely low gas content in a vacuum environment, the fused quartz window cannot effectively transfer energy through air thermal convection, resulting in heat accumulation. As the number of laser pulses increases, the laser damage threshold has an overall downward trend. The energy accumulation process of these two aspects increases the damage risk of fused quartz and reduces the ability of fused quartz to resist laser damage.

[0004] Optical components are important components of laser systems, and their quality and stability directly affect the performance and life of laser systems. In high-power laser systems, optical components will gradually become damaged when exposed to laser radiation for a long time. Understanding and predicting the evolution of this damage is of great significance for improving system reliability and extending component life.

[0005] In the prior art, for example, the Chinese patent "A method for studying damage to optical components irradiated by laser" with publication number CN115014718B discloses a technical solution for studying damage to optical components by experimental methods. This method measures the damage threshold of the optical component, uses an irradiation energy density less than the damage threshold to measure the life of the optical component under long-term laser irradiation, uses fluorescence spectroscopy combined with changes in helium-neon lasers to determine whether the component is damaged, and monitors changes or damage such as deformation, stress mutation, and cracks of the component in real time.

[0006] However, the above methods mainly focus on real-time monitoring and experimental testing, and have the following shortcomings: First, the prediction ability is limited, and it is impossible to predict in advance the damage trend of optical components under different laser irradiation times; second, the parameter correlation is insufficient, and no quantitative relationship model between the physical property parameters of optical components and the development of damage has been established; third, the environmental limitations are mainly aimed at conventional environments, and the differences in damage mechanisms of optical components in vacuum environments are not considered; fourth, there is a lack of analysis of composite damage mechanisms, and the composite mechanism of photochemical and photothermal damage has not been deeply analyzed; fifth, the experimental cycle is long, and a large number of experiments are required to obtain the damage law, which is inefficient. In addition, although this method mentions the thermal accumulation effect, it lacks a detailed quantitative analysis model for thermal effects.

[0007] Therefore, a method is needed to predict the damage evolution of optical components based on physical parameters, so as to achieve early prediction of damage, reduce experimental cycle and improve evaluation efficiency. Summary of the invention

[0008] The purpose of the present invention is to provide a method for predicting the evolution of damage to optical components based on laser irradiation, so as to solve the technical problems in the prior art such as limited prediction ability, insufficient parameter correlation, and poor environmental adaptability, and to achieve accurate prediction of the evolution of damage to optical components.

[0009] To achieve the above object, the technical solution provided by the present invention is: a method for predicting the damage evolution of optical components based on laser irradiation, comprising: Acquiring physical parameters and laser irradiation parameters of the optical element, wherein the physical parameters include oxygen-silicon ratio, transmittance and absorption coefficient, and the laser irradiation parameters include wavelength, energy density and repetition frequency; Establish a prediction model for laser irradiation damage evolution, including: Based on the physical parameters and laser irradiation parameters, a multi-environment damage prediction model is constructed, wherein the multi-environment damage prediction model includes a mapping relationship between environmental parameters and damage thresholds; Based on the physical parameters, an oxygen-silicon ratio-transmittance-damage threshold correlation model is constructed, wherein the correlation model characterizes the evolution relationship between the physical parameters and the number of laser shots; Based on the laser irradiation parameters, a heat-light-force multi-physics field coupling model is constructed, wherein the coupling model characterizes the damage mechanism under the interaction of multiple physical fields; The damage threshold evolution of the optical element after different laser irradiations is predicted by the multi-environment damage prediction model, the correlation model and the coupling model. The prediction results include a trend curve of the damage threshold changing with the number of irradiations and a critical damage point.

[0010] As a pre-selection, the construction of the multi-environment damage prediction model specifically includes: Establish an environmental parameter mapping system to quantify the relationship between different vacuum levels, gas components and damage parameters; Construct a three-dimensional state diagram of temperature, pressure and irradiation to predict the change trajectory of damage threshold under different environmental parameters; Determine critical state identification parameters to determine the combination of environmental conditions that are most likely to cause damage.

[0011] As a pre-selection, the construction of the oxygen-silicon ratio-transmittance-damage threshold correlation model specifically includes: A subsurface oxygen-to-silicon ratio gradient prediction model is established to predict the distribution of oxygen-to-silicon ratio from the surface to the subsurface; Construct a microstructure-macro performance bridge system to link microscopic defects with macroscopic optical properties; Design an advanced damage threshold prediction model, the prediction formula is: , in, is the damage threshold after N pulses, is the single pulse damage threshold, N is the number of pulses, S is the transmittance parameter, f(T,P) is the temperature and pressure correction function, g(O:Si) is the oxygen-silicon ratio influence function, is the stress influence function.

[0012] As a preselection, the temperature pressure correction function is expressed as: , Where T is the actual temperature, is the reference temperature, P is the actual pressure, is the reference pressure, α and β are material related constants.

[0013] As a preselection, the oxygen-silicon ratio influence function is expressed as: , Among them, O:Si is the oxygen-silicon ratio of the material, and γ is a material-related constant.

[0014] As a preselection, the stress influence function is expressed as: , Where σ is the stress in the optical element, is the reference stress and δ is a material related constant.

[0015] As a pre-selection, the construction of the heat-light-force multi-physics field coupling model specifically includes: Establish a quantitative analysis framework for heat accumulation effects and calculate multi-pulse temperature rise and critical heat accumulation conditions; Construct phase change critical point prediction technology to predict the critical conditions of local melting and evaporation of materials; Develop time-space resolved thermal accumulation effect analysis technology to simulate the inter-pulse heat diffusion process.

[0016] As a pre-selection, the thermal accumulation effect quantitative analysis framework includes: Single pulse temperature rise calculation: , Multi-pulse temperature rise calculation: , Critical heat accumulation condition judgment: , in, is the absorbed energy, ρ is the material density, c is the specific heat capacity, V is the affected volume, is the characteristic pulse number, N is the pulse frequency, is the critical temperature rise.

[0017] As a pre-selection, also includes: Based on the damage threshold evolution trend curve, a multi-level early warning mechanism is established to grade damage risks; Design intelligent adjustment strategies for laser parameters based on the current damage status to maximize the service life of optical components; Build component individualization characterization technology to provide customized usage suggestions for different optical components.

[0018] As a pre-selection, also includes: Establish an experimental verification and model calibration system, including: Develop a hierarchical and progressive verification scheme to conduct multi-level verification from micro parameters to macro performance; Build error analysis and calibration mechanisms to identify sources of forecast errors and dynamically adjust model parameters; Design a real-time feedback optimization system to continuously improve the accuracy of the prediction model through adding new experimental data.

[0019] The method provided by the present invention has the following beneficial effects: 1. A damage prediction model based on physical parameters was established to achieve early prediction of damage evolution of optical components, reduce experimental cycles, and improve evaluation efficiency; 2. A multi-environment damage prediction model was constructed, which expanded the scope of application of the prediction method and can adapt to various environmental conditions from standard atmospheric pressure to high vacuum and from low temperature to high temperature; 3. An oxygen-silicon ratio-transmittance-damage threshold correlation model was established, revealing the correlation mechanism between microscopic physical parameters and macroscopic damage characteristics, thus improving the scientificity and accuracy of the prediction; 4. A heat-light-force multi-physics field coupling model was constructed, which comprehensively considered the interaction of various physical fields and analyzed the composite damage mechanism in more depth; 5. A multi-level early warning mechanism and intelligent parameter adjustment strategy have been designed to extend the service life of optical components and improve the reliability of the laser system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flow chart of a method for predicting damage evolution of optical elements based on laser irradiation provided by the present invention; Figure 2 It is a structural schematic diagram of the multi-environment damage prediction model of the present invention; Figure 3 It is a relationship diagram of the oxygen-silicon ratio-transmittance-damage threshold correlation model of the present invention; Figure 4 A schematic diagram of the physical field interaction of the heat-light-force multi-physics field coupling model of the present invention; Figure 5 This is a prediction curve diagram of the damage threshold of the present invention changing with the number of laser shots; Figure 6 is a curve diagram showing the relationship between transmittance and oxygen-silicon ratio; Figure 7 It is the fitting curve diagram of the damage threshold changing with the laser firing times; Figure 8 This is the relationship between the oxygen-silicon ratio and the laser firing times; Fig. 9 is the linear relationship between the absorption coefficient and the oxygen-silicon ratio; Fig.10 This is the correlation curve between damage threshold and absorption coefficient. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0022] Example 1 like Figures 1 to 10 As shown, the present invention provides a method for predicting the evolution of damage of an optical element based on laser irradiation, comprising the following steps: First, obtain the physical parameters of the optical element and the laser irradiation parameters. The physical parameters include oxygen-silicon ratio, transmittance, and absorption coefficient, which can be measured experimentally or obtained from the material database. The laser irradiation parameters include wavelength, energy density, and repetition frequency, which are usually determined according to the actual application scenario.

[0023] Next, a laser irradiation damage evolution prediction model is established. This prediction model is the core of the present invention and includes three key components: a multi-environment damage prediction model, an oxygen-silicon ratio-transmittance-damage threshold correlation model, and a heat-light-force multi-physics field coupling model. These three models describe the mechanism of damage evolution of optical components from different perspectives, and together constitute a complete prediction system.

[0024] Then, the established prediction model is used to predict the evolution of the damage threshold of optical components after different laser irradiation times. The prediction results include the trend curve of the damage threshold changing with the number of laser irradiation times and the critical damage point, which are of great guiding significance for evaluating the service life and safety margin of optical components.

[0025] In practical applications, this prediction method can help researchers and engineers understand in advance the damage risk of optical components during use, take corresponding preventive measures, extend component life, and improve system reliability.

[0026] Example 2 like Figure 2 As shown, the construction of the multi-environment damage prediction model is to solve the problem of poor environmental adaptability in the existing technology, and can adapt to various environmental conditions from standard atmospheric pressure to high vacuum, from low temperature to high temperature.

[0027] The construction of this model first requires the establishment of an environmental parameter mapping system to quantify the relationship between different vacuum degrees, gas components and damage parameters. In actual implementation, we divide the vacuum degree into 10 -3 Pa to 10 -8 Pa has different levels, and the influence of the components of residual gas (such as O2, N2, H2O, etc.) on the surface state of optical components is considered. For example, in a high vacuum environment, the reduction of residual moisture content will lead to a decrease in moisture adsorbed on the surface of optical components, which in turn affects their damage mechanism.

[0028] Secondly, a temperature-pressure-irradiation three-dimensional state diagram is constructed to predict the change trajectory of the damage threshold under different environmental parameters. This state diagram covers the three-dimensional parameter space of temperature (4K-500K), pressure (vacuum-standard atmospheric pressure) and laser irradiation (energy density, frequency), which can intuitively show the comprehensive impact of environmental parameters on the damage threshold. By performing parameter interpolation and extrapolation in this state diagram, the damage evolution under untested environmental conditions can be predicted.

[0029] In addition, it is necessary to determine the critical state identification parameters to judge the combination of environmental conditions that are most likely to cause damage. These parameters are usually determined based on a large amount of experimental data and theoretical analysis, including critical temperature, critical pressure, and critical irradiation energy density. In actual applications, the system will automatically identify whether the current environmental conditions are close to the critical state based on these parameters and provide corresponding warnings.

[0030] Experiments have shown that there are significant differences in damage mechanisms under different environmental conditions. For example, in a vacuum environment, due to the reduced efficiency of heat conduction, the heat accumulation effect is more significant, resulting in a generally lower damage threshold than in a standard atmospheric pressure environment. Through the establishment of this model, this difference can be accurately quantified and predicted.

[0031] Example 3 like Figure 3 As shown, the construction of the oxygen-silicon ratio-transmittance-damage threshold correlation model is to reveal the correlation mechanism between microscopic physical parameters and macroscopic damage characteristics and to improve the scientificity and accuracy of the prediction.

[0032] First, a subsurface oxygen-to-silicon ratio gradient prediction model was established to predict the oxygen-to-silicon ratio distribution from the surface to the subsurface. Through experiments and theoretical calculations, we found that laser irradiation causes the oxygen-to-silicon ratio on the fused quartz surface to change, forming a gradient distribution from the surface to the subsurface (0-500nm depth). The model can predict the evolution of this gradient distribution based on laser irradiation parameters (such as wavelength, energy density, and frequency).

[0033] Secondly, a microstructure-macro performance bridge system is constructed to link micro defects with macro optical properties. The system calculates defect formation energy based on density functional theory, predicts the generation probability of different defect types (such as ODCs, NBOHC, etc.), and establishes a quantitative relationship model between defect density and absorption coefficient. In this way, the evolution of micro defects can be associated with changes in macro optical properties, providing a theoretical basis for damage prediction. Multi-pulse laser damage is considered to be a heat accumulation process. In addition, an advanced damage threshold prediction model is designed to predict the damage threshold under different conditions. The model is expressed as: , In the formula is the single pulse laser damage threshold. In a vacuum environment, the single pulse laser damage threshold of fused quartz corresponding to a 50% damage probability is J1=22.0J / cm 2 . N is the number of pulses, is the laser damage threshold after N pulses, S is the transmittance of the material, f(T,P) is the temperature and pressure correction function, g(O;Si) is the oxygen-silicon ratio influence function, is the stress influence function.

[0034] The temperature and pressure correction function is expressed as: , Where T is the actual temperature, is the reference temperature, P is the actual pressure, is the reference pressure, and is a material-dependent constant. For fused silica, a typical value is .

[0035] The oxygen-silicon ratio influence function is expressed as: , Where O:Si is the oxygen-silicon ratio of the material, and γ is a material-related constant. For fused quartz, the typical value is Y=0.3.

[0036] The stress influence function is expressed as: , in, is the stress in the optical element, is the reference stress, is a material-dependent constant. For fused silica, a typical value is .

[0037] After N laser irradiations, the heat accumulation process of fused quartz is reflected in the factor Ignoring the reflection process for now, the laser passing through fused silica will not cause heat accumulation in the material. The changes in the material structure and properties at the damage point are caused by the energy absorbed by the material. Therefore, the factor The S in has the physical meaning of material transmittance.

[0038] The absorption coefficient changes with the number of times it is emitted. The relationship between the transmittance and absorption coefficient of the material after different times of emission can be derived through the Beer-Lambert law. , in is the incident laser intensity, is the laser intensity transmitted through the medium, is the absorption coefficient, is the distance the laser travels in the medium. Defined as transmittance, the expression can be obtained: , The formula can finally be expressed as: , The obtained results were processed and fitted data were plotted. The relationship between several parameters was obtained. The data processing procedure is as follows: According to the existing experimental results, at a wavelength of 355nm and an energy density of 4J / cm 2 After 30 laser irradiations, the damage threshold of fused silica was determined to be 17.82 J / cm 2 , the parameter S is calculated by the formula to be 0.938, and the transmittance of fused quartz under 355nm wavelength laser single pulse irradiation is 0.975, indicating that after 30 irradiations, the transmittance of fused quartz is reduced to 0.938, which is a reasonable result. And using the above formula, the transmittance and damage threshold under different irradiations can be calculated, providing a reasonable evaluation scheme for the damage growth of fused quartz.

[0039] Through the above model, the damage threshold evolution of optical components under different conditions can be accurately predicted, providing a scientific basis for component service life assessment.

[0040] like Figure 6 As shown in the figure, there is an obvious linear relationship between the transmittance (S) and the oxygen-silicon ratio (O:Si). When the oxygen-silicon ratio is 2.0, the transmittance reaches a maximum value of 0.975; as the oxygen-silicon ratio decreases, the transmittance also decreases. Experimental data show that when the oxygen-silicon ratio decreases from 2.0 to 1.4, the transmittance decreases from 0.975 to about 0.933. This change corresponds to the change in the microstructure of the material.

[0041] like Figure 7 As shown in the figure, the damage threshold decreases with the increase of laser shots, showing a nonlinear attenuation trend. The single-pulse damage threshold is 22.0 J / cm², which decreases to 16.3 J / cm² after 100 shots, further decreases to 13.9 J / cm² after 1000 shots, and stabilizes at about 12.9 J / cm² after 3000 shots. The curve fitting adopts the prediction formula proposed by the present invention, which is highly consistent with the experimental data, proving the effectiveness of the model.

[0042] like Figure 8 As shown in the figure, the oxygen-silicon ratio decreases with the increase of laser shots. It changes rapidly in the first 100 irradiations, rapidly decreasing from the initial value of 2.0 to about 1.435. Then the rate of change gradually slows down and stabilizes at about 1.409 at 3000 shots. This change reflects the process of material structure change caused by laser irradiation.

[0043] like Fig. 9 As shown in the figure, the absorption coefficient and the oxygen-silicon ratio show a good linear relationship. The fitting equation of the two is y=-2893.48x+6524.10, and the correlation coefficient R²=0.9724, indicating that the absorption coefficient increases with the decrease of the oxygen-silicon ratio. This relationship provides an important basis for predicting the damage threshold.

[0044] like Fig.10 As shown in the figure, there is an obvious negative correlation between the damage threshold and the absorption coefficient. When the absorption coefficient increases, the damage threshold decreases, and the relationship between the two can be fitted by a power function. This relationship reveals the mechanism by which the material absorption characteristics affect the damage threshold.

[0045] Example 4 like Figure 4 As shown in the figure, the construction of the thermal-optical-mechanical multi-physics field coupling model is to comprehensively consider the interaction of various physical fields and to analyze the composite damage mechanism more deeply.

[0046] First, a quantitative analysis framework for thermal accumulation effect is established to calculate the temperature rise and critical heat accumulation conditions in multiple pulses. The framework includes the following key calculations: Single pulse temperature rise calculation: , Multi-pulse temperature rise calculation: , Critical heat accumulation condition judgment: , in, is the absorbed energy, ρ is the material density, c is the specific heat capacity, V is the affected volume, is the characteristic pulse number, N is the pulse frequency, is the critical temperature rise.

[0047] Characteristic pulse number It is expressed as the ratio of the cooling time constant to the pulse interval: , in, is the cooling time constant, is the pulse interval.

[0048] Secondly, a phase transition critical point prediction technology is constructed to predict the critical conditions for local melting and evaporation of materials. This technology is based on the principles of thermodynamics and takes into account the phase change characteristics of materials under different environmental conditions. For example, in a vacuum environment, the evaporation temperature of the material will decrease, so the corresponding critical conditions will also change. By establishing a mapping relationship between environmental conditions and phase transition critical points, the critical state of damage under different environments can be accurately predicted.

[0049] In addition, a time-space resolved heat accumulation effect analysis technology was developed to simulate the heat diffusion process between pulses. This technology uses the finite element analysis method, taking into account the thermal conductivity characteristics, geometric structure and boundary conditions of the material, and can accurately simulate the distribution evolution of heat in space and time after each pulse. This analysis is of great significance for understanding the formation and evolution of local hot spots in the heat accumulation process.

[0050] In practical applications, these three components work together to form a complete thermal-optical-mechanical multi-physics field coupling analysis system, which can comprehensively describe the complex physical processes inside optical components under laser irradiation and provide a solid theoretical basis for damage prediction.

[0051] Example 5 like Figure 6 As shown, based on the damage threshold evolution trend curve, a multi-level warning mechanism can be established to grade the damage risk. The present invention designs a four-level warning mechanism based on risk level, including attention, warning, danger and emergency replacement. Each level has clear judgment criteria and processing suggestions.

[0052] Caution level: triggered when the damage threshold drops to 90% of the initial value. It is recommended to pay close attention to the component status. Warning level: triggered when the damage threshold drops to 80% of the initial value, it is recommended to reduce the frequency of use or reduce the laser energy; Danger level: triggered when the damage threshold drops to 70% of the initial value, it is recommended to prepare replacement components; Emergency Replacement Level: Triggered when the damage threshold drops to 60% of the initial value and the component must be replaced immediately to avoid system failure.

[0053] In combination with damage risk assessment, the present invention also designs an intelligent adjustment strategy for laser parameters based on the current damage state to maximize the service life of optical components. This strategy automatically adjusts the operating parameters of the laser (such as energy density, repetition frequency, etc.) according to the predicted damage evolution trend, slowing down the development of damage while ensuring system performance. For example, when an increase in damage risk is detected, the system can appropriately reduce the laser repetition frequency and increase the inter-pulse cooling time to reduce the heat accumulation effect.

[0054] In addition, the present invention also constructs a component individualization characterization technology to provide customized usage suggestions for different optical components. Based on hyperspectral imaging, this technology obtains the component surface defect distribution map, establishes a component personalized digital archive, and records the data of the entire manufacturing, testing, and use process. In this way, the system can provide personalized usage suggestions based on the characteristics of each component, further extending the life of the component.

[0055] Experiments show that the multi-level warning and intelligent adjustment can significantly extend the service life of optical components. In typical application scenarios, compared with traditional methods, the present invention can extend the service life of components by more than 30% and significantly reduce system operating costs.

[0056] Example 6 To ensure the accuracy and reliability of the prediction model, the present invention establishes a complete experimental verification and model calibration system, including a hierarchical progressive verification scheme, an error analysis and calibration mechanism, and a real-time feedback optimization system.

[0057] The hierarchical verification scheme conducts multi-level verification from micro parameters to macro performance, including four levels: The first layer is micro-parameter verification, which verifies the prediction accuracy of micro-parameters such as oxygen-silicon ratio and defect density; The second layer is mesoscopic parameter verification, which verifies the prediction accuracy of optical parameters such as absorption coefficient and transmittance; The third layer is macro performance verification, which verifies the prediction accuracy of macro performance indicators such as damage threshold and life prediction; The fourth layer is the prediction verification of the whole system, which verifies the overall prediction effect of damage evolution under different environments and different laser parameters.

[0058] The error analysis and calibration mechanism is used to identify the source of prediction errors and dynamically adjust the model parameters. This mechanism uses a Bayesian approach to automatically optimize key parameters in the model, such as the temperature and pressure correction function, based on the difference between experimental data and prediction results. and , Y in the oxygen-silicon ratio influence function, and Etc. In this way, the model can continuously improve itself and increase prediction accuracy.

[0059] The real-time feedback optimization system continuously improves the accuracy of the prediction model by adding new experimental data. The system uses an incremental learning algorithm that enables the model to learn and improve from new data while retaining the knowledge learned in the past. In addition, the system has established a model evolution history analysis technology to evaluate the effectiveness of model improvements and ensure the correct direction of the model optimization process.

[0060] The experimental results show that, through the above-mentioned experimental verification and model calibration system, after multiple iterative optimizations, the prediction error of the damage threshold of the prediction model of the present invention is controlled within 5%, and the prediction error of the damage time is controlled within 10%, which meets the actual application requirements.

[0061] Example 7 To verify the actual effect of the method of the present invention, we predicted and verified the damage evolution of fused silica window components in a high-power laser system. The system uses an ultraviolet laser with a wavelength of 355nm, a pulse width of 10ns, a repetition frequency of 100Hz, and a single pulse energy density of 5J / cm².

[0062] First, the initial physical parameters of the fused quartz window were obtained: oxygen-silicon ratio of 2.0, transmittance of 0.975, and absorption coefficient of 740.4cm⁻¹. At the same time, the single pulse damage threshold was measured to be 22.0J / cm².

[0063] Then, the prediction model established by the present invention is used to predict the evolution of the damage threshold of the window after different laser irradiation times. The prediction results show that as the number of shots increases, the damage threshold shows a gradual downward trend: it drops to 19.4J / cm² after 10 shots, to 16.3J / cm² after 100 shots, to 13.9J / cm² after 1000 shots, and to 12.9J / cm² after 3000 shots.

[0064] At the same time, the change trend of the oxygen-silicon ratio was predicted: it dropped to 1.579 after 10 shots, to 1.435 after 100 shots, to 1.411 after 1000 shots, and to 1.409 after 3000 shots. This change reflects the change in material structure caused by laser irradiation.

[0065] To verify the accuracy of the prediction results, we conducted an actual laser irradiation experiment. The maximum error between the experimentally measured damage threshold and the predicted value was 4.3%, which verified the high accuracy of the method of the present invention.

[0066] In addition, based on the prediction results, the system automatically generates usage recommendations for the window components: it enters the warning level at around 2000 rounds (about 5.5 hours of continuous work), and it is recommended to reduce the laser energy density to 4J / cm²; it enters the danger level at around 4500 rounds (about 12.5 hours of continuous work), and it is recommended to prepare to replace the window components.

[0067] In actual application, by following this suggestion, the average service life of the window components of the laser system was extended from the original 15 hours to 20 hours, an increase of 33.3%, which greatly reduced the system operation cost and verified the practical value of the method of the present invention.

[0068] Table 1 Physical parameters and damage threshold prediction results of fused silica window under different laser irradiation times

[0069] It can be clearly seen from Table 1 that with the increase in the number of laser shots, the oxygen-silicon ratio gradually decreases, the transmittance decreases accordingly, the absorption coefficient increases, and the damage threshold decreases. These data strongly verify the accuracy of the prediction model of the present invention. The maximum error between the prediction result and the experimental measurement value is 4.3%, indicating that the present method has good applicability and reliability.

[0070] These tabular data are also Figure 6-10 The data source is used to comprehensively demonstrate the relationship between the evolution of physical parameters of optical components and the damage threshold through a combination of tables and graphs.

[0071] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for predicting damage evolution of optical components based on laser irradiation, characterized in that: include: Acquiring physical parameters and laser irradiation parameters of the optical element, wherein the physical parameters include oxygen-silicon ratio, transmittance and absorption coefficient, and the laser irradiation parameters include wavelength, energy density and repetition frequency; Establish a prediction model for laser irradiation damage evolution, including: Based on the physical parameters and laser irradiation parameters, a multi-environment damage prediction model is constructed, wherein the multi-environment damage prediction model includes a mapping relationship between environmental parameters and damage thresholds; Based on the physical parameters, an oxygen-silicon ratio-transmittance-damage threshold correlation model is constructed, wherein the correlation model characterizes the evolution relationship between the physical parameters and the number of laser shots; Based on the laser irradiation parameters, a heat-light-force multi-physics field coupling model is constructed, wherein the coupling model characterizes the damage mechanism under the interaction of multiple physical fields; The damage threshold evolution of the optical element after different laser irradiations is predicted by the multi-environment damage prediction model, the correlation model and the coupling model. The prediction results include a trend curve of the damage threshold changing with the number of irradiations and a critical damage point.

2. The method for predicting damage evolution of optical components based on laser irradiation according to claim 1, characterized in that: The construction of the multi-environment damage prediction model specifically includes: Establish an environmental parameter mapping system to quantify the relationship between different vacuum levels, gas components and damage parameters; Construct a three-dimensional state diagram of temperature, pressure and irradiation to predict the change trajectory of damage threshold under different environmental parameters; Determine critical state identification parameters to determine the combination of environmental conditions that are most likely to cause damage.

3. The method for predicting damage evolution of optical components based on laser irradiation according to claim 1, characterized in that: The construction of the oxygen-silicon ratio-transmittance-damage threshold correlation model specifically includes: A subsurface oxygen-to-silicon ratio gradient prediction model is established to predict the distribution of oxygen-to-silicon ratio from the surface to the subsurface; Construct a microstructure-macro performance bridge system to link microscopic defects with macroscopic optical properties; Design an advanced damage threshold prediction model, the prediction formula is: ， in, is the damage threshold after N pulses, is the single pulse damage threshold, N is the number of pulses, S is the transmittance parameter, f(T,P) is the temperature and pressure correction function, g(O:Si) is the oxygen-silicon ratio influence function, and h(σ) is the stress influence function.

4. The method for predicting damage evolution of optical components based on laser irradiation according to claim 3, characterized in that: The temperature and pressure correction function is expressed as: ， Where T is the actual temperature, is the reference temperature, P is the actual pressure, is the reference pressure, α and β are material related constants.

5. The method for predicting damage evolution of optical components based on laser irradiation according to claim 3, characterized in that: The oxygen-silicon ratio influence function is expressed as: ， Among them, O:Si is the oxygen-silicon ratio of the material, and γ is a material-related constant.

6. The method for predicting damage evolution of optical components based on laser irradiation according to claim 3, characterized in that: The stress influence function is expressed as: , Where σ is the stress in the optical element, is the reference stress and δ is a material related constant.

7. The method for predicting damage evolution of optical components based on laser irradiation according to claim 1, characterized in that: The construction of the heat-light-force multi-physics field coupling model specifically includes: Establish a quantitative analysis framework for heat accumulation effects and calculate multi-pulse temperature rise and critical heat accumulation conditions; Construct phase change critical point prediction technology to predict the critical conditions of local melting and evaporation of materials; Develop time-space resolved thermal accumulation effect analysis technology to simulate the inter-pulse heat diffusion process.

8. The method for predicting damage evolution of optical components based on laser irradiation according to claim 7, characterized in that: The quantitative analysis framework of thermal accumulation effect includes: Single pulse temperature rise calculation: , Multi-pulse temperature rise calculation: , Critical heat accumulation condition judgment: , in, is the absorbed energy, ρ is the material density, c is the specific heat capacity, V is the affected volume, is the characteristic pulse number, N is the pulse frequency, is the critical temperature rise.

9. The method for predicting damage evolution of optical components based on laser irradiation according to claim 1, characterized in that: Also includes: Based on the damage threshold evolution trend curve, a multi-level early warning mechanism is established to grade damage risks; Design intelligent adjustment strategies for laser parameters based on the current damage status to maximize the service life of optical components; Build component individualization characterization technology to provide customized usage suggestions for different optical components.

10. The method for predicting damage evolution of optical components based on laser irradiation according to claim 1, characterized in that: Also includes: Establish an experimental verification and model calibration system, including: Develop a hierarchical and progressive verification scheme to conduct multi-level verification from micro parameters to macro performance; Build error analysis and calibration mechanisms to identify sources of forecast errors and dynamically adjust model parameters; Design a real-time feedback optimization system to continuously improve the accuracy of the prediction model through adding new experimental data.

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