A stray light evaluation method and device based on extinction coating surface scattering interpolation

Abstract

The embodiment of the application provides a stray light evaluation method and device based on extinction coating surface scattering interpolation, which generates candidate surface scattering characteristic data by using an interpolation scheme for the forward scattering and backward scattering interval, quantifies the influence of forward scattering and backward scattering on stray light, that is, completes the fine quantitative evaluation of the scattering characteristics of the extinction coating, and then combines the stray light measurement results of the optical system with the same base material and extinction coating model as the extinction coating sample to screen out surface scattering characteristic data with a difference meeting a preset result difference condition, thereby improving the accuracy of the surface scattering characteristic data and the credibility of the stray light simulation evaluation result, and providing a reliable basis for the targeted selection and iterative optimization of the extinction coating material.

Description

Technical Field

[0001] This application relates to the field of optical simulation and measurement technology, and in particular to a stray light evaluation method and apparatus based on surface scattering interpolation of an extinction coating. Background Technology

[0002] As the detection sensitivity of space astronomical observation systems continues to improve, stray light suppression has become a key aspect of ensuring system imaging performance. Stray light can degrade the system's signal-to-noise ratio and image contrast, and in severe cases, it can obscure the effective signal of the target. Traditional mechanical extinction structures such as light shields and light-blocking rings have limitations in application due to constraints on equipment size and weight. Therefore, extinction coatings have become the core means of stray light suppression in optical systems.

[0003] Currently, the industry generally relies on optical simulation software to complete stray light path analysis and system optimization. However, the accuracy of simulation calculations is highly dependent on complete measured data of surface scattering from matting coatings. But measured scattering characteristics of coatings suffer from drawbacks such as long testing cycles, high costs, and incomplete coverage of operating conditions, requiring appropriate interpolation algorithms and sampling strategies to improve scattering data support. Existing research on matting coatings often uses absorptivity as the single core evaluation indicator, resulting in low reliability of stray light simulation assessment results and making it difficult to provide a reliable basis for targeted selection and iterative optimization of matting coating materials. Summary of the Invention

[0004] The purpose of this application is to provide a stray light evaluation method and apparatus based on surface scattering interpolation of matte coatings, so as to improve the reliability of stray light simulation evaluation results and provide a reliable basis for targeted selection and iterative optimization of matte coating materials. The specific technical solution is as follows:

[0005] In a first aspect, embodiments of this application provide a stray light evaluation method based on surface scattering interpolation of an extinction coating, the method comprising:

[0006] Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles;

[0007] Each of the bidirectional reflectance distribution functions is interpolated according to a variety of different interpolation schemes to obtain the interpolation results of each interpolation scheme, which are used as candidate surface scattering characteristic data of the matting coating sample; wherein, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval;

[0008] Stray light was measured on the optical system to obtain the measurement results, wherein the substrate and matte coating of the optical system were of the same type as the matte coating sample;

[0009] The optical system is simulated for stray light using the scattering characteristic data of each candidate surface, and the simulation results corresponding to the scattering characteristic data of each candidate surface are obtained.

[0010] From the candidate surface scattering characteristic data, the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition is selected as the surface scattering characteristic data of the optical system.

[0011] In one possible implementation, the various interpolation schemes include the following:

[0012] Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region;

[0013] The various interpolation schemes include one or more of the following interpolation schemes:

[0014] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation.

[0015] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, while in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation.

[0016] In one possible implementation, the bidirectional reflection distribution function is | -sin | is the independent variable; where, The scattering angle is... The angle of reflection is the specular reflection angle.

[0017] In one possible implementation, the step of interpolating each of the bidirectional reflection distribution functions according to multiple different interpolation schemes to obtain the interpolation results of each interpolation scheme includes:

[0018] For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each of the bidirectional reflection distribution functions according to the interpolation schemes, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities;

[0019] The surface scattering characteristic data whose differences between the corresponding simulation results and the measurement results meet the preset result difference conditions are selected as the surface scattering characteristic data of the optical system, including:

[0020] Surface scattering characteristic data whose differences between the simulation results and the measurement results satisfy a preset result difference condition are selected, and the surface scattering characteristic data whose interpolation density satisfies a preset interpolation density condition are used as the surface scattering characteristic data of the optical system.

[0021] In one possible implementation, the measurement results and the simulation results include point source transmittance.

[0022] In one possible implementation, obtaining the bidirectional reflectance distribution function of the matte-coated sample at multiple incident angles includes:

[0023] Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and with a scattering angle range of [-80°, 80°].

[0024] Secondly, embodiments of this application provide a stray light evaluation device based on surface scattering interpolation of an extinction coating, the device comprising:

[0025] The acquisition module is used to acquire the bidirectional reflection distribution function of the matte coating sample at multiple incident angles;

[0026] An interpolation module is used to interpolate each of the bidirectional reflectance distribution functions according to a variety of different interpolation schemes, and obtain the interpolation results of each interpolation scheme as candidate surface scattering characteristic data of the matting coating sample. Among them, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval.

[0027] The measurement module is used to measure stray light in the optical system and obtain measurement results, wherein the substrate and matte coating of the optical system are the same as those of the matte coating sample.

[0028] The simulation module is used to simulate stray light in the optical system using the scattering characteristic data of each candidate surface, and to obtain the simulation results corresponding to the scattering characteristic data of each candidate surface.

[0029] The filtering module is used to filter out the surface scattering characteristic data from each of the candidate surface scattering characteristic data, and select the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition, as the surface scattering characteristic data of the optical system.

[0030] In one possible implementation, the various interpolation schemes include the following:

[0031] Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region;

[0032] The various interpolation schemes include one or more of the following interpolation schemes:

[0033] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation.

[0034] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, while in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation.

[0035] In one possible implementation, the bidirectional reflection distribution function is | -sin | is the independent variable, where, The scattering angle is... The angle of reflection is the specular reflection angle.

[0036] In one possible implementation, the step of interpolating each of the bidirectional reflection distribution functions according to multiple different interpolation schemes to obtain the interpolation results of each interpolation scheme includes:

[0037] For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each of the bidirectional reflection distribution functions according to the interpolation schemes, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities;

[0038] The surface scattering characteristic data whose differences between the corresponding simulation results and the measurement results meet the preset result difference conditions are selected as the surface scattering characteristic data of the optical system, including:

[0039] Surface scattering characteristic data whose differences between the simulation results and the measurement results satisfy a preset result difference condition are selected, and the surface scattering characteristic data whose interpolation density satisfies a preset interpolation density condition are used as the surface scattering characteristic data of the optical system.

[0040] In one possible implementation, the measurement results and the simulation results include point source transmittance.

[0041] In one possible implementation, obtaining the bidirectional reflectance distribution function of the matte-coated sample at multiple incident angles includes:

[0042] Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and with a scattering angle range of [-80°, 80°].

[0043] Thirdly, embodiments of this application provide an electronic device, including:

[0044] Memory, used to store computer programs;

[0045] When a processor executes a program stored in memory, it implements the stray light evaluation method based on surface scattering interpolation of an extinction coating described in the first aspect.

[0046] Fourthly, embodiments of this application also provide a computer program product containing instructions that, when run on a computer, cause the computer to execute the stray light evaluation method based on scattering interpolation of the matting coating surface described in the first aspect.

[0047] Beneficial effects of the embodiments in this application:

[0048] This application provides a stray light evaluation method and apparatus based on surface scattering interpolation of an matte coating. The method involves obtaining bidirectional reflection distribution functions at multiple incident angles of a matte coating sample; interpolating each bidirectional reflection distribution function using various interpolation schemes to obtain interpolation results for each scheme, which serve as candidate surface scattering characteristic data for the matte coating sample; wherein at least one interpolation scheme has an interpolation interval for forward scattering and at least one interpolation scheme has an interpolation interval for backscattering; stray light measurement is performed on an optical system to obtain measurement results; wherein the substrate and matte coating model of the optical system are the same as those of the matte coating sample; stray light simulation is performed on the optical system using each candidate surface scattering characteristic data to obtain simulation results corresponding to each candidate surface scattering characteristic data; from the candidate surface scattering characteristic data, surface scattering characteristic data whose differences between the simulation results and measurement results meet preset result difference conditions are selected as the surface scattering characteristic data of the optical system. In this embodiment, an interpolation scheme is used to generate candidate surface scattering characteristic data for the forward and backward scattering ranges. The influence of forward and backward scattering on stray light is quantified, which completes a refined quantitative evaluation of the scattering characteristics of the matting coating. Then, by combining the stray light measurement results of the optical system with the same substrate and matting coating model as the matting coating sample, surface scattering characteristic data whose differences from the measurement results meet the preset result difference conditions are selected. This improves the accuracy of the surface scattering characteristic data, thereby improving the credibility of the stray light simulation evaluation results. This provides a reliable basis for the targeted selection and iterative optimization of matting coating materials.

[0049] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0051] Figure 1 A schematic flowchart illustrating a stray light evaluation method provided in an embodiment of this application;

[0052] Figure 2 A schematic diagram of the bidirectional reflection distribution function as a function of scattering angle provided in an embodiment of this application;

[0053] Figure 3 The bidirectional reflection distribution function provided in the embodiments of this application varies with | -sin |A schematic diagram of the distribution curve;

[0054] Figure 4 A schematic flowchart illustrating another stray light evaluation method provided in this application embodiment;

[0055] Figure 5 A schematic diagram illustrating the variation curve of relative root mean square error with interpolation sampling density provided in the embodiments of this application;

[0056] Figure 6 A schematic diagram of the point source transmittance versus off-axis angle curve provided in an embodiment of this application;

[0057] Figure 7 A schematic diagram of the ratio of the point source transmittance measurement result to the simulation result as a function of the off-axis angle, provided in the embodiments of this application;

[0058] Figure 8 A flowchart illustrating another stray light evaluation method provided in this application embodiment;

[0059] Figure 9 This is a schematic diagram of a physical sample of a matte coating provided in an embodiment of this application;

[0060] Figure 10 This is a schematic diagram of a light shield model provided in an embodiment of this application;

[0061] Figure 11 This is a schematic diagram of the actual light shield provided in the embodiments of this application;

[0062] Figure 12 This is a schematic diagram of the stray light evaluation device provided in the embodiments of this application;

[0063] Figure 13 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0065] To improve the reliability of stray light simulation evaluation results and support the targeted selection and iterative optimization of matting coating materials, this application provides a stray light evaluation method based on surface scattering interpolation of matting coatings. (See [link to relevant documentation]). Figure 1 The methods include:

[0066] S101, obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles;

[0067] S102, interpolate each bidirectional reflection distribution function according to a variety of different interpolation schemes to obtain the interpolation results of each interpolation scheme, which serve as candidate surface scattering characteristic data for the matting coating sample;

[0068] Wherein, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval;

[0069] S103, stray light measurement is performed on the optical system to obtain the measurement results;

[0070] The substrate and matte coating model of the optical system are the same as those of the matte coating sample.

[0071] S104, stray light simulation of the optical system is performed using the scattering characteristic data of each candidate surface, and the simulation results corresponding to the scattering characteristic data of each candidate surface are obtained.

[0072] S105: From the candidate surface scattering characteristic data, select the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition, and use it as the surface scattering characteristic data of the optical system.

[0073] In this embodiment, an interpolation scheme is used to generate candidate surface scattering characteristic data for the forward and backscattering ranges, quantifying the impact of forward and backscattering on stray light. This achieves a refined quantitative evaluation of the scattering characteristics of the matting coating. By combining the stray light measurement results of optical systems with the same substrate and matting coating model as the matting coating sample, surface scattering characteristic data whose differences from the measured results meet the preset result difference conditions are selected. This improves the accuracy of the surface scattering characteristic data obtained from the simulation, thereby enhancing the reliability of the stray light simulation evaluation results. This provides a reliable basis for the targeted selection and iterative optimization of matting coating materials.

[0074] The following will explain steps S101-S105:

[0075] In step S101 of this embodiment, the matte coating sample includes a matte coating material (i.e., the matte coating model below) and a substrate material (i.e., the substrate below). The matte coating material and the substrate material are determined according to the stray light suppression index requirements of the optical system and the usage environment.

[0076] For example, for aerospace optical systems with stringent stray light suppression requirements and operating environments involving alternating high and low temperatures, the matte coating material can be anodized black film or aerospace-grade black paint coating that is adaptable to the space environment, and the substrate material can be a metal substrate such as aluminum alloy or titanium alloy that is consistent with the system's main structure; for ordinary optical systems that mainly suppress stray light in the visible light band and operate in a stable environment, the matte coating material can be a matte black paint, sandblasted black coating, or other matte coatings that are easy to process and cost-effective, and the substrate material can be a conventional structural substrate such as optical-grade aluminum alloy or engineering plastic.

[0077] In selecting the incident angle, professional technicians can choose the angle based on industry standards or work experience. For example, a higher sampling density can be set in the angular range where the scattering intensity changes drastically, while the number of sampling points can be appropriately reduced in the region where the scattering intensity is gentle. This avoids the loss of key scattering information due to missing angular sampling and ensures that the surface scattering characteristic data obtained by subsequent interpolation can truly reflect the multi-angle optical scattering law of the matting coating.

[0078] The bidirectional reflection distribution function (BRDF) is a function used to describe the light reflection characteristics of an object's surface. It represents the reflection characteristics of an object's surface at any exit angle under different incident angles, and is the ratio of reflected radiance to incident radiance.

[0079] In step S102 of this embodiment, the bidirectional reflectance distribution function obtained in step S101 is measured discrete BRDF data. The measured BRDF data can only cover a limited angle, while high-precision stray light simulation requires denser BRDF data. Therefore, it is necessary to interpolate the aforementioned bidirectional reflectance distribution function.

[0080] Here, the interpolation interval refers to the range of values ​​for the independent variable selected when interpolating the two-way reflectance distribution function. At least one interpolation scheme has an interpolation interval that is a forward scattering interval, meaning that among multiple interpolation schemes, there exists at least one scheme that performs interpolation processing only or primarily on the two-way reflectance distribution function data corresponding to forward scattering, in order to obtain candidate surface scattering characteristic data that can characterize the forward scattering properties of the matting coating. At least one interpolation scheme has an interpolation interval that is a backscattering interval, meaning that among multiple interpolation schemes, there exists at least one interpolation scheme that performs interpolation processing only or primarily on the two-way reflectance distribution function data corresponding to backscattering, in order to obtain candidate surface scattering characteristic data that can characterize the backscattering properties of the matting coating.

[0081] Specifically, the forward scattering interval can be understood as the scattering data interval where the scattering direction is on the forward side relative to the specular reflection direction, and the backscattering interval can be understood as the scattering data interval where the scattering direction is on the backward side relative to the specular reflection direction. By including at least the interpolation schemes corresponding to the forward scattering interval and the backscattering interval among various interpolation schemes, candidate surface scattering characteristic data that emphasize forward scattering characteristics and backscattering characteristics can be generated respectively. Subsequently, stray light simulation of the optical system is performed using each candidate surface scattering characteristic data, and the simulation results are compared with the stray light measurement results of the optical system. This determines the degree of fit between the forward scattering characteristic data, the backscattering characteristic data, or a combination of both, and the stray light simulation of the target optical system, thereby selecting surface scattering characteristic data that is closer to the measured results.

[0082] In step S103 of this embodiment, since the substrate and matting coating model of the optical system are the same as those of the matting coating sample, the measurement results obtained by performing stray light measurement on the optical system can be used as the true value for stray light evaluation. These measurement results can be used to verify whether the candidate surface scattering characteristic data constructed from the matting coating sample is suitable for stray light simulation of the optical system.

[0083] The measurement results and the simulation results described below can be characterized by various forms of data, including but not limited to stray light intensity data at different off-axis angles and point source transmittance at different off-axis angles.

[0084] For example, the optical system can be a light shield system. According to the light shield design model, the physical processing and manufacturing of the light shield is completed, wherein the base material and matte coating material of the light shield are the same as the base material and matte coating material of the matte coating sample.

[0085] When measuring stray light, the stray light of the actual object under the light shield is measured according to the preset off-axis angle, and the measurement results at the corresponding angle are recorded. It can be understood that the preset off-axis angle should be the same as the off-axis angle used in the stray light simulation process in step S104. For example, an off-axis angle θ range of 25°~80° is set, with an angle interval of 5°, which includes a total of 12 off-axis angles. The stray light of the actual object under the light shield is measured, and the measured stray light intensity data at the corresponding off-axis angle is recorded as the measurement result.

[0086] Understandably, in this article Figure 1 The execution order of steps S102 and S103 shown is only one possible example. In other embodiments, step S103 may be executed first, followed by step S102, or steps S102 and S103 may be executed in parallel. No specific limitation is made here.

[0087] In step S104 of this embodiment, the scattering characteristic data of each candidate surface are simulated and analyzed to obtain simulation results. It is understood that the actual measurement results can be used as the reference true value for stray light evaluation, and the simulation results obtained based on the candidate surface scattering characteristic data can be used as the simulated value for stray light evaluation. To ensure the comparability of the differences between the two, the measurement results and simulation results should be used to evaluate stray light from the same evaluation dimension. That is, the measurement results and simulation results should correspond to the same or comparable optical system, incident angle, off-axis angle range, and stray light evaluation index.

[0088] For example, both the measurement results and the simulation results can be stray light intensity data at different off-axis angles, or point source transmittance at different off-axis angles. In this case, the measurement results at the same off-axis angle or the corresponding off-axis angle can be compared with the simulation results to determine the simulation accuracy corresponding to the scattering characteristic data of each candidate surface. By using the above method, it is possible to avoid the distortion of evaluation due to inconsistencies in evaluation indicators, test conditions, or angle sampling, and improve the reliability of the candidate surface scattering characteristic data screening results.

[0089] Specifically, an optical system model can be built using simulation software such as TracePro, Advanced Systems Analysis Program (ASAP), and FRED. The scattering characteristic data of each candidate surface are then assigned to the corresponding surface of the optical system model, giving the model the corresponding surface scattering properties. Subsequently, an off-axis angle range consistent with the stray light measurement process in step S103 is set. Multiple parallel beams with different off-axis angles are used to simulate a point source at infinity to perform ray tracing simulations, and the simulated stray light intensity data at each off-axis angle is recorded as the simulation results. TracePro is one type of optical engineering simulation software, and FRED is another.

[0090] In step S105 of this embodiment, taking stray light intensity data at different off-axis angles as an example where both the measurement and simulation results are obtained, the simulated stray light intensity data at the same off-axis angle is compared and analyzed with the measured stray light intensity data obtained from the physical measurement to obtain the difference between the two. If the difference meets the preset result difference condition, it is determined that the current candidate surface scattering characteristic data is suitable for the optical system and can be directly used for subsequent stray light simulation analysis.

[0091] This difference can be characterized by the difference, ratio, relative error, relative root mean square error, etc., and the embodiments of this application do not limit this. The preset result difference conditions include, but are not limited to, the ratio of the measured value (i.e., the measurement result) to the simulated value (i.e., the simulation result) being less than a preset ratio threshold, the relative root mean square error being less than a preset error threshold, etc.

[0092] In one possible embodiment, the aforementioned various interpolation schemes include the following interpolation schemes:

[0093] Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region;

[0094] Several different interpolation schemes include one or more of the following:

[0095] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation.

[0096] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, while in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation.

[0097] By applying this embodiment, by configuring a variety of targeted scattering interval interpolation schemes, the interpolation strategy can be flexibly matched according to the stray light interference characteristics and working optical path angle range of the optical system. This solves the problems of poor adaptability and distorted fitting of scattering data in traditional single interpolation methods, improves the accuracy of the surface scattering characteristic data obtained from simulation, and thus improves the credibility of stray light simulation evaluation results. This provides a reliable basis for the targeted selection and iterative optimization of matting coating materials.

[0098] Furthermore, the data format of the candidate surface scattering characteristic data obtained by interpolation using the interpolation scheme of this embodiment can be directly adapted to stray light simulation tools without additional conversion processing. It can be directly imported into the optical model to complete ray tracing calculations without significantly modifying the existing simulation process. It is compatible with existing industrial simulation systems and has high engineering practicality and versatility.

[0099] In this embodiment, a multi-dimensional interpolation strategy is designed for the continuous fitting scenario of discrete sampling data of the bidirectional reflectance distribution function (BRDF) of the matte coating surface. Since actual optical testing can only acquire scattering sampling data from a limited angle, BRDF parameters at non-sampling angles need to be calculated through interpolation. However, the forward and backscattering characteristics of optical surfaces differ significantly, and the dominant scattering mechanisms differ across different scattering ranges. A single interpolation method cannot meet the simulation requirements of full-angle scattering; therefore, four differentiated interpolation schemes are set:

[0100] The first method, interpolation only for the forward scattering interval: interpolation fitting is performed only on the discrete BRDF data within the forward scattering angle interval in optical scattering. Data for the backscattering interval and other angle intervals are directly discarded without interpolation calculation. This method is suitable for simulation scenarios of optical systems where forward stray light is the main interference. For example, using the bidirectional reflection distribution function with | -sin Taking | as the independent variable, the forward scattering interval is represented as 0~| -sin |, among which The scattering angle is... The angle of reflection of the mirror. Scattering angle The maximum value, =80°.

[0101] The second method, interpolation only for the backscattering interval: interpolation is performed only for the discrete BRDF data within the backscattering angle interval, while the corresponding data in the forward scattering interval is directly discarded without interpolation. This method is suitable for simulation scenarios of optical systems with prominent back reflection and stray light interference. For example, using the bidirectional reflection distribution function with | -sin Taking | as the independent variable, the backscattering range is represented as 0~| +sin |, among which The scattering angle is... The angle of reflection of the mirror. =80°.

[0102] The third method is the forward and backward joint mean interpolation scheme: interpolation optimization is performed on both the forward and backward scattering intervals. In the forward scattering interval, the mean values ​​of the forward and backward BRDF data are fused for interpolation to take into account the influence of the two types of scattering characteristics. If there is no forward BRDF data, backward BRDF data is used for interpolation in the other scattering intervals, which can weaken the calculation bias caused by a single scattering data.

[0103] The fourth type is a combined forward scattering and backscattering interpolation scheme: This scheme achieves accurate partitioned interpolation of the scattering range. Forward scattering range uses forward BRDF data for interpolation to match the true optical characteristics of forward scattering. If there is no forward BRDF data, back BRDF data is used for interpolation in the remaining scattering ranges.

[0104] In one possible embodiment, the aforementioned bidirectional reflection distribution function is | -sin | is the independent variable; where, The scattering angle is... The scattering angle is the specular reflection angle. Applying this embodiment avoids the nonlinear errors caused by directly using the scattering angle as the independent variable, improving the physical realism and accuracy of the bidirectional reflection distribution function. Simultaneously, it makes the parameter curves in the forward and backward scattering intervals continuous and smooth, improving the accuracy and stability of discrete data interpolation, reducing stray light simulation deviations, and enhancing the accuracy and robustness of stray light simulation results for optical systems. It is adaptable to simulation scenarios with multiple angles and operating conditions.

[0105] In this embodiment, the conventional bidirectional reflection distribution function is typically expressed directly in terms of the scattering angle. As an example, plot the bidirectional reflection distribution function curve using it as the independent variable. Figure 2 , Figure 2 The image shows six incident angles: 0°, 15°, 30°, 45°, 60°, and 75°. Lower bidirectional reflection distribution function as a function of scattering angle The curve showing the change.

[0106] However, the surface scattering behavior of the matte coating is essentially dominated by the difference between the incident and scattered wave vector projection components, rather than the angle itself. This embodiment introduces | -sin Using a sinusoidal angle transformation as the independent variable of the bidirectional reflectance distribution function to characterize the angular shift difference between the incident and scattered rays, the light scattering behavior of the matting coating surface can be realistically depicted. For example, see... Figure 3 , Figure 3 The image shows six incident angles: 0°, 15°, 30°, 45°, 60°, and 75°. The bidirectional reflection distribution function varies with | -sin The curves represent the changes in scattering, where curve B represents backscattering and curve F represents forward scattering. The scattering angle is used to characterize the exit angle of light after reflection and scattering by the surface of the matte coating. The specular reflection angle is used to characterize the angle at which light is reflected specularly on the coating surface. Its value is equal to the incident angle and located on opposite sides of the normal. By calculating the absolute difference between the sine values ​​of the two, the degree of deflection of the scattered light relative to the specular reflection direction can be normalized, eliminating the nonlinear deviation caused by the simple angle value, and giving the scattering characteristics under different incident angles and different scattering angles a uniform variation law.

[0107] In one possible embodiment, when interpolating each bidirectional reflection distribution function according to multiple different interpolation schemes, a uniform interpolation density can be used to interpolate each bidirectional reflection distribution function.

[0108] In another possible embodiment, see Figure 4 The aforementioned step S102 can be refined into step S1021, and step S105 can be refined into step S1051, specifically:

[0109] S1021, For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each bidirectional reflection distribution function according to the interpolation scheme, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities;

[0110] S1051, filter out the surface scattering characteristic data whose difference between the simulation results and the measurement results meets the preset result difference condition, and use the surface scattering characteristic data whose interpolation density meets the preset interpolation density condition as the surface scattering characteristic data of the optical system.

[0111] By applying this embodiment, various interpolation densities are performed for different interpolation schemes, and the surface scattering characteristic data whose interpolation densities meet the preset interpolation density conditions are further selected from the candidate surface scattering characteristic data that meet the preset interpolation density conditions. This can improve the accuracy of stray light simulation while avoiding the increase in simulation time caused by excessively high interpolation density, thereby balancing computational accuracy and simulation efficiency.

[0112] In steps S1021 and S1051 of this embodiment, the interpolation density can be characterized by the number of interpolation samples. The more interpolation samples, the higher the interpolation density; the fewer interpolation samples, the lower the interpolation density. Different interpolation densities result in different interpolation results, that is, the amount of candidate surface scattering characteristic data and the time consumed in stray light simulation calculation are different, and the corresponding stray light simulation accuracy may also differ.

[0113] In one possible embodiment, to investigate the impact of the number of interpolations on the accuracy of stray light simulation of the optical system, five sets of interpolation sampling numbers (50, 80, 100, 150, and 200) can be selected based on a combined forward scattering and backscattering interpolation scheme. These numbers are then used to interpolate and reconstruct the bidirectional reflectance distribution function data for each sample, resulting in five sets of candidate surface scattering characteristic data for the extinction coating sample at different interpolation densities. Subsequently, stray light simulation of the optical system is performed using these five sets of candidate surface scattering characteristic data to obtain simulation results corresponding to each interpolation density, allowing for comparison of the impact of changes in interpolation density on simulation accuracy.

[0114] As mentioned above, the difference between the measurement results and the simulation results can be characterized by the difference, ratio, relative error, relative root mean square error, etc. Taking the example that both the measurement results and the simulation results include point source transmittance (point source transmittance will be explained in detail below, and will not be repeated here), and the difference between the two is characterized by relative root mean square error, the relative root mean square error (RRMSE) can be calculated by the following formula (1):

[0115] ...Formula (1)

[0116] in, This represents the measurement result of the point source transmittance corresponding to the i-th off-axis angle. This represents the simulation result of the point source transmittance corresponding to the i-th off-axis angle, where n is the number of off-axis angles.

[0117] See Figure 5 When the number of interpolation samples increased from 50 to 200, the relative root mean square error decreased by only 0.0154, and the overall fluctuation range was limited. This indicates that further increasing the number of interpolation samples has little effect on improving the simulation accuracy, and the numerical noise introduced by the interpolation density has a weak impact and can be basically ignored.

[0118] Meanwhile, excessively high interpolation density increases the amount of candidate surface scattering characteristic data and significantly increases the computation time for stray light simulation. Therefore, based on the premise that the difference between the simulation results and the measurement results meets the preset result difference condition, further screening can be performed according to the preset interpolation density condition. This preset interpolation density condition may include: selecting candidate surface scattering characteristic data with a smaller number of interpolation samples, shorter simulation computation time, or higher computational efficiency, while meeting the simulation accuracy requirements.

[0119] Specifically, among the five sets of interpolation sampling numbers mentioned above, the simulation accuracy corresponding to an interpolation sampling number of 100 is sufficient to meet the preset requirements. Furthermore, compared to interpolation sampling numbers of 150 and 200, it reduces the data size and lowers the computational burden of the simulation. Therefore, surface scattering characteristic data with an interpolation sampling number of 100 can be selected as the surface scattering characteristic data for the optical system. This approach ensures the accuracy of stray light simulation while avoiding a significant increase in simulation computation time due to excessively high interpolation density, thus balancing simulation accuracy and computational efficiency.

[0120] In one possible embodiment, as described above, the measurement and simulation results may include point source transmittance. Applying this embodiment, point source transmittance characterizes the optical system's ability to suppress off-axis stray light. Using point source transmittance as a comparison index between measurement and simulation results allows for comparison under the same physical meaning and evaluation dimensions, avoiding inconsistencies caused by using different stray light evaluation quantities. Furthermore, point source transmittance is typically characterized as a relative quantity, which reduces the impact of absolute differences in light source intensity, detector response, etc., on the comparison results, thereby improving the stability and comparability of simulation accuracy evaluation between different candidate surface scattering characteristic data. Thus, surface scattering characteristic data with a high degree of matching to measured stray light characteristics can be more accurately selected, improving the reliability of optical system stray light simulation results.

[0121] In this embodiment, point source transmittance (PST) can be defined as the ratio of the irradiance generated on the detector by the radiation from a point source target at an off-axis angle θ outside the field of view after passing through the optical system to the irradiance at the entrance of the optical system under test. Point source transmittance can characterize the ability of the optical system to suppress off-axis stray light, and therefore can be used as a comparison index between stray light measurement results and stray light simulation results.

[0122] For example, as mentioned above, an off-axis angle range of 25° to 80° can be set, and off-axis angles can be selected at 5° intervals, resulting in a total of 12 off-axis angles: 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, and 80°. For each of these off-axis angles, stray light measurements and simulations are performed to obtain the corresponding measurement and simulation results.

[0123] See Figure 6 The curves showing the change of point source transmittance with off-axis angle in both measurement and simulation results are as follows: Figure 6 As shown. The measurement results are... Figure 6 The measured values ​​are included; the simulation results include the point source transmittance obtained after simulating stray light from candidate surface scattering characteristic data obtained based on different interpolation schemes.

[0124] Specifically, the simulation results may include: simulation results obtained by simulating the scattering characteristics of candidate surfaces based on the first interpolation scheme, whereby the first interpolation scheme can be a forward scattering interpolation scheme, i.e. Figure 6 The simulation results are obtained by simulating the forward scattering in the candidate surface based on the scattering characteristic data obtained by the second interpolation scheme, which can be a backscattering interpolation scheme, i.e. Figure 6 Backscattering in the sample; simulation results obtained from simulations of candidate surface scattering characteristic data based on the third interpolation scheme, which can be a joint forward and backward mean interpolation scheme, i.e. Figure 6 The average forward and backward scattering values; and the simulation results obtained from simulating the candidate surface scattering characteristics data based on the fourth interpolation scheme, which can be a forward and backward partitioned independent interpolation scheme, i.e. Figure 6 The combination of forward and backward scattering in the middle.

[0125] To quantify the above Figure 6 The difference between the measured results and the simulation results of each interpolation scheme can be calculated by comparing the ratio of the measured point source transmittance to the simulated point source transmittance obtained by the four interpolation schemes. The distribution curve of the obtained ratio can be found in [reference needed]. Figure 7Except for the relatively large deviation in the simulated point source transmittance results corresponding to the forward scattering interpolation scheme, the ratio curves of the measured point source transmittance results and the simulated point source transmittance results corresponding to the other three interpolation schemes generally match the trend. The simulated point source transmittance results corresponding to the forward scattering and backscattering combined interpolation scheme have the best fit with the measured results, with ratios of 3.29 and 4.24 at 19° and 20° off-axis angles, respectively, while the ratios at other angles are all below 2.2. The forward scattering and backscattering mean interpolation scheme is the second best, with ratios reaching 3.78 and 4.86 only at 19° and 20° off-axis angles, respectively, while the ratios at other angles do not exceed 2.4. For the above two interpolation schemes, the ratios of the measured point source transmittance results and the simulated point source transmittance results at all off-axis angles are both less than 5. Based on this, taking into account both forward scattering and backscattering components can reduce stray light simulation errors and is superior to the forward scattering interpolation scheme and the backscattering interpolation scheme.

[0126] The backscattering region interpolation ranked third in terms of consistency, with ratios of 4.52 and 5.52 for off-axis angles of 19° and 20°, respectively, while the ratios for other angles were all less than 2.83. The ratio between the point source transmittance measurement results and the point source transmittance simulation results of the forward scattering interpolation scheme generally increased with increasing off-axis angle, showing a local secondary peak of 13.97 at 20°; the maximum ratio across the entire angle range occurred at 80°, reaching a value as high as 64.

[0127] By comparing the simulation results corresponding to the different interpolation schemes with the measured values, the degree of matching between the candidate surface scattering characteristic data reconstructed by each interpolation scheme and the stray light characteristics of the actual optical system can be determined, and the interpolation scheme with higher simulation accuracy can be selected accordingly.

[0128] In one possible embodiment, the aforementioned step S101 can be refined to step S1011, specifically:

[0129] Step S1011: Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and a scattering angle range of [-80°, 80°]. By obtaining the bidirectional reflection distribution function of the matte coating sample within a relatively wide range of incident and scattering angles in this embodiment, the surface scattering characteristics of the matte coating sample under different incident conditions and scattering directions can be characterized more completely. This provides a sufficiently comprehensive measured data foundation for subsequent interpolation and reconstruction of candidate surface scattering characteristic data, thereby improving the integrity and reliability of the stray light simulation input data.

[0130] In step S1011 of this embodiment, to ensure that the test covers a large-angle incident range and a wide-angle scattering range, the incident angle range and the scattering angle range can be predetermined. The incident angle range defines the angle range of the incident light relative to the surface normal of the matte coating sample or a preset reference direction, and the scattering angle range defines the angle range of the scattered light relative to the surface normal of the sample or a preset reference direction.

[0131] In selecting the incident angle within the defined range, professional technicians can choose the angle based on industry standards, testing equipment capabilities, actual operating conditions of the optical system, or empirical data. The incident angle can be selected at equal intervals or at non-equal intervals based on the stray light sensitivity range or key incident directions in the optical system. Similarly, the scattering angle can be determined based on the angular resolution of the testing equipment, the scattering gradient of the matte coating sample, and the accuracy requirements of subsequent interpolation.

[0132] For example, the angle of incidence can be set. The range is 0° to 75°, with angular intervals of 15°, encompassing six incident angles: 0°, 15°, 30°, 45°, 60°, and 75°; the scattering angle θ s The range is -80° to 80°, with 1° intervals, encompassing a total of 161 scattering angles. Within the aforementioned incident and scattering angle range, the surface scattering characteristics of the matting coating sample, i.e., the measured data of the bidirectional reflectance distribution function, can be measured and recorded.

[0133] The above method can cover the scattering response of the matting coating sample under conditions ranging from small to large incident angles. On the other hand, it can cover the scattering information in the forward scattering direction, the backscattering direction, and the area near the normal, thereby reducing the interpolation extrapolation error caused by insufficient measured angle range and improving the accuracy of subsequent candidate surface scattering characteristic data.

[0134] It is understandable that the scattering angles given in this article Angle of incidence Off-axis angle θ, specular reflection angle The specific values ​​for the angle range, angle interval, and number of angles are merely examples to illustrate the technical solution of this embodiment and do not constitute a limitation on the scope of protection of this application. In other embodiments, the scattering angle... Angle of incidence Off-axis angle θ, specular reflection angle The range of values, angle intervals, and number of angles can be adjusted based on factors such as the actual working field of view of the optical system, the stray light incident path, the gradient of the sample scattering characteristics, simulation accuracy requirements, and computing resources.

[0135] For example, the incident angle can be selected at equal intervals, or a smaller angle interval can be used in stray light sensitive angle regions or angle regions where scattering characteristics change rapidly; the scattering angle range can be expanded or reduced according to the measurable range of the test equipment and the scattering direction of interest to the optical system; the off-axis angle range and off-axis angle interval can also be set according to the stray light test specifications of the optical system or the actual application scenario. Therefore, this application specifies the scattering angle... Angle of incidence Off-axis angle θ, specular reflection angle The specific values ​​such as the range of values, angle intervals, and number of angles are not limited.

[0136] To further illustrate the stray light assessment method based on surface scattering interpolation of the matting coating provided in this application, the following description is provided in conjunction with a flowchart and specific implementation scenarios:

[0137] See Figure 8 The stray light assessment method based on surface scattering interpolation of matting coatings includes the following steps:

[0138] Step S801, matte coating selection and sample production; which is equivalent to the aforementioned step S101;

[0139] Step S802, measuring the surface scattering characteristics of the matte coating sample; that is, equivalent to the aforementioned step S101;

[0140] Step S803, surface scattering characteristic data preprocessing; that is, equivalent to the aforementioned step S101;

[0141] Step S804, design of surface scattering characteristic data interpolation scheme; that is, equivalent to the aforementioned step S102;

[0142] Step S805, stray light simulation analysis of the optical system model; which is equivalent to the aforementioned step S104;

[0143] Step S806, experimental measurement of stray light from the optical system; that is, equivalent to the aforementioned step S103;

[0144] Step S807: Compare the stray light simulation results with the measurement results; that is, equivalent to the aforementioned step S105.

[0145] Step S808: Robustness analysis of the surface scattering characteristic data interpolation scheme.

[0146] In step S801, within a certain space optical equipment light shield system, based on the stray light suppression requirements of the optical system and the operating environment, suitable matting coating materials and substrate materials are screened and determined, and a matting coating sample is fabricated. (See [link to relevant documentation]). Figure 9 , Figure 9The image shown is a physical sample of the matte coating. The field of view of the light shield meets 2ω≥12° (circular field of view), and the envelope size Φ meets 110×120mm. In this embodiment, the matte coating material of the sample is an inorganic matte coating material, and the substrate material is an aluminum alloy substrate, as an example for analysis.

[0147] In step S802, the surface scattering characteristics of the matte coating sample are measured. To ensure that the test covers a wide incident angle range and a broad scattering range, the incident angle is set. The range is 0° to 75°, with angular intervals of 15°, encompassing a total of 6 incident angles: 0°, 15°, 30°, 45°, 60°, and 75°; the scattering angle θ s The range is -80° to 80°, with 1° intervals, encompassing a total of 161 scattering angles. Measured data of the surface scattering characteristics, i.e., the bidirectional reflectance distribution function, are recorded.

[0148] In step S803, after obtaining the measured data of the bidirectional reflection distribution function, the bidirectional reflection distribution function is plotted as a function of six incident angles: 0°, 15°, 30°, 45°, 60°, and 75°. -sin The changing curves can be plotted on logarithmic scales for both the horizontal and vertical axes, which can be used to divide and calculate the distribution range of forward and backward scattering.

[0149] In step S804, four interpolation schemes are used to interpolate the bidirectional reflection distribution function, namely forward scattering interpolation, backscattering interpolation, interpolation of the mean of forward and backscattering, and combined interpolation of forward and backscattering, to obtain four sets of candidate surface scattering characteristic data. To control variables, the number of interpolations in each of the four interpolation schemes can be set to 100.

[0150] In step S805, during stray light simulation analysis, a certain type of light shield is used as the optical structure. A light shield model is established in the optical simulation software. (See the light shield model for details.) Figure 10 Four sets of candidate surface scattering characteristic data were imported. An off-axis angle range of 25° to 80° was set, with an angle interval of 5°. A total of 12 parallel beams at different off-axis angles were used to simulate an infinitely distant point source for ray tracing analysis. Finally, the simulation results of the point source transmittance at each off-axis angle were obtained.

[0151] In step S806, during the stray light experimental measurement, the physical fabrication of the light shield is completed according to the light shield design model. The substrate type and matte coating model of the light shield are consistent with the matte coating sample. (See the physical light shield sample for details.) Figure 11 Set off-axis angle parameters consistent with the simulation analysis, perform stray light measurement on the actual object of the light shield, and obtain the point source transmittance measurement results corresponding to each off-axis angle.

[0152] In step S807, after obtaining the measurement and simulation results, the ratio of the measured transmittance of the actual point source of the light shield to the simulated transmittance of the point source obtained by the four interpolation schemes is calculated. If the simulated transmittance of the point source corresponding to the combined forward and backward scattering interpolation has the best fit with the measurement results, and the ratio of the measured transmittance of the point source to the simulated transmittance of the point source at the full off-axis angle meets the preset result difference condition, then the candidate surface scattering characteristic data corresponding to the combined forward and backward scattering interpolation is used as the surface scattering characteristic data of the optical system.

[0153] In step S808, further, based on the combined forward and backscattering interpolation scheme, five sets of interpolation densities (50, 80, 100, 150, and 200) are selected to reconstruct the bidirectional reflectance distribution function data. The reconstructed databases of the surface scattering characteristics of the extinction coating under the five different interpolation densities are then imported into the light shield model to complete the point source transmittance simulation calculation and calculate the relative root mean square error. If the relative root mean square error only decreases slightly when the interpolation density increases from 50 to 200, and the overall fluctuation range is limited, it can be determined that the numerical noise introduced by the sampling density has a weak impact. While ensuring that the simulation accuracy meets the requirements, the interpolation sampling number can be selected as 100 to reduce unnecessary simulation computation time.

[0154] In addition to the aforementioned light shields, the stray light assessment method provided in this application embodiment can also be used in various space optical systems such as space astronomical observation telescopes, star sensors, and aerospace light shields. It can support stray light simulation and verification during the ground test phase, as well as serve stray light suppression design and analysis under on-orbit service conditions. It covers multiple working scenarios such as ground and space, and has a wide range of applicable optical objects and applications.

[0155] Corresponding to the aforementioned stray light assessment method based on scattering interpolation of the surface of the matting coating, this application also provides a stray light assessment device based on scattering interpolation of the surface of the matting coating, see [link to relevant documentation]. Figure 12 The device includes:

[0156] The acquisition module 1201 is used to acquire the bidirectional reflection distribution function of the matte coating sample at multiple incident angles;

[0157] Interpolation module 1202 is used to interpolate each of the bidirectional reflection distribution functions according to a variety of different interpolation schemes, and obtain the interpolation results of each interpolation scheme as candidate surface scattering characteristic data of the matting coating sample. Among them, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval.

[0158] The measurement module 1203 is used to measure stray light in the optical system and obtain measurement results, wherein the substrate and matte coating of the optical system are the same as the matte coating sample.

[0159] Simulation module 1204 is used to perform stray light simulation on the optical system using the scattering characteristic data of each candidate surface, and to obtain the simulation results corresponding to the scattering characteristic data of each candidate surface.

[0160] The filtering module 1205 is used to filter out the surface scattering characteristic data from each of the candidate surface scattering characteristic data, and select the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition, as the surface scattering characteristic data of the optical system.

[0161] In this embodiment, an interpolation scheme is used to generate candidate surface scattering characteristic data for the forward and backscattering ranges, quantifying the impact of forward and backscattering on stray light. This achieves a refined quantitative evaluation of the scattering characteristics of the matting coating. By combining the stray light measurement results of optical systems with the same substrate and matting coating model as the matting coating sample, surface scattering characteristic data whose differences from the measured results meet the preset result difference conditions are selected. This improves the accuracy of the surface scattering characteristic data obtained from the simulation, thereby enhancing the reliability of the stray light simulation evaluation results. This provides a reliable basis for the targeted selection and iterative optimization of matting coating materials.

[0162] In one possible implementation, the various interpolation schemes include the following:

[0163] Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region;

[0164] The various interpolation schemes include one or more of the following interpolation schemes:

[0165] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation.

[0166] Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, while in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation.

[0167] In one possible implementation, the bidirectional reflection distribution function is | -sin | is the independent variable, where, The scattering angle is... The angle of reflection is the specular reflection angle.

[0168] In one possible implementation, the step of interpolating each of the bidirectional reflection distribution functions according to multiple different interpolation schemes to obtain the interpolation results of each interpolation scheme includes:

[0169] For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each of the bidirectional reflection distribution functions according to the interpolation schemes, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities;

[0170] The surface scattering characteristic data whose differences between the corresponding simulation results and the measurement results meet the preset result difference conditions are selected as the surface scattering characteristic data of the optical system, including:

[0171] Surface scattering characteristic data whose differences between the simulation results and the measurement results satisfy a preset result difference condition are selected, and the surface scattering characteristic data whose interpolation density satisfies a preset interpolation density condition are used as the surface scattering characteristic data of the optical system.

[0172] In one possible implementation, the measurement results and the simulation results include point source transmittance.

[0173] In one possible implementation, obtaining the bidirectional reflectance distribution function of the matte-coated sample at multiple incident angles includes:

[0174] Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and with a scattering angle range of [-80°, 80°].

[0175] This application also provides an electronic device, such as... Figure 13 As shown, it includes a processor 1301, a communication interface 1302, a memory 1303, and a communication bus 1304, wherein the processor 1301, the communication interface 1302, and the memory 1303 communicate with each other through the communication bus 1304.

[0176] Memory 1303 is used to store computer programs;

[0177] When processor 1301 executes a program stored in memory 1303, it performs the following steps:

[0178] Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles;

[0179] Each of the bidirectional reflectance distribution functions is interpolated according to a variety of different interpolation schemes to obtain the interpolation results of each interpolation scheme, which are used as candidate surface scattering characteristic data of the matting coating sample. Among them, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval.

[0180] Stray light was measured on the optical system to obtain the measurement results, wherein the substrate and matte coating of the optical system were of the same type as the matte coating sample;

[0181] The optical system is simulated for stray light using the scattering characteristic data of each candidate surface, and the simulation results corresponding to the scattering characteristic data of each candidate surface are obtained.

[0182] From the candidate surface scattering characteristic data, the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition is selected as the surface scattering characteristic data of the optical system.

[0183] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0184] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0185] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0186] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0187] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of any of the above-described stray light evaluation methods based on surface scattering interpolation of an extinction coating.

[0188] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to perform any of the stray light evaluation methods based on surface scattering interpolation of the matting coating described in the above embodiments.

[0189] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (SSD)).

[0190] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0191] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0192] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A stray light assessment method based on surface scattering interpolation of an extinction coating, characterized in that, The method includes: Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles; Each of the bidirectional reflectance distribution functions is interpolated according to a variety of different interpolation schemes to obtain the interpolation results of each interpolation scheme, which are used as candidate surface scattering characteristic data of the matting coating sample; wherein, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval; Stray light was measured on the optical system to obtain the measurement results, wherein the substrate and matte coating of the optical system were of the same type as the matte coating sample; The optical system is simulated for stray light using the scattering characteristic data of each candidate surface, and the simulation results corresponding to the scattering characteristic data of each candidate surface are obtained. From the candidate surface scattering characteristic data, the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition is selected as the surface scattering characteristic data of the optical system.

2. The method according to claim 1, characterized in that, The various interpolation schemes include the following: Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region; The various interpolation schemes include one or more of the following interpolation schemes: Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation. Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, while in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation.

3. The method according to claim 2, characterized in that, The bidirectional reflection distribution function is based on | -sin | is the independent variable; where, The scattering angle is... The angle of reflection is the specular reflection angle.

4. The method according to claim 1, characterized in that, The process of interpolating each of the bidirectional reflection distribution functions according to multiple different interpolation schemes to obtain the interpolation results of each interpolation scheme includes: For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each of the bidirectional reflection distribution functions according to the interpolation schemes, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities; The surface scattering characteristic data whose differences between the corresponding simulation results and the measurement results meet the preset result difference conditions are selected as the surface scattering characteristic data of the optical system, including: Surface scattering characteristic data whose differences between the simulation results and the measurement results satisfy a preset result difference condition are selected, and the surface scattering characteristic data whose interpolation density satisfies a preset interpolation density condition are used as the surface scattering characteristic data of the optical system.

5. The method according to claim 1, characterized in that, The measurement results and the simulation results include point source transmittance.

6. The method according to claim 1, characterized in that, The acquisition of the bidirectional reflectance distribution function of the matte coating sample at multiple incident angles includes: Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and with a scattering angle range of [-80°, 80°].

7. A stray light evaluation device based on surface scattering interpolation of an extinction coating, characterized in that, The device includes: The acquisition module is used to acquire the bidirectional reflection distribution function of the matte coating sample at multiple incident angles; An interpolation module is used to interpolate each of the bidirectional reflectance distribution functions according to a variety of different interpolation schemes, and obtain the interpolation results of each interpolation scheme as candidate surface scattering characteristic data of the matting coating sample. Among them, the interpolation interval of at least one interpolation scheme is the forward scattering interval, and the interpolation interval of at least one interpolation scheme is the backscattering interval. The measurement module is used to measure stray light in the optical system and obtain measurement results, wherein the substrate and matte coating of the optical system are the same as those of the matte coating sample. The simulation module is used to simulate stray light in the optical system using the scattering characteristic data of each candidate surface, and to obtain the simulation results corresponding to the scattering characteristic data of each candidate surface. The filtering module is used to filter out the surface scattering characteristic data from each of the candidate surface scattering characteristic data, and select the surface scattering characteristic data whose difference between the simulation result and the measurement result meets the preset result difference condition, as the surface scattering characteristic data of the optical system.

8. The apparatus according to claim 7, characterized in that, The various interpolation schemes include the following: Interpolation is performed only in the forward scattering region; interpolation is performed only in the backscattering region; The various interpolation schemes include one or more of the following interpolation schemes: Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the mean of the forward scattering bidirectional reflection distribution function and the backscattering bidirectional reflection distribution function is used for interpolation. In other intervals, the backscattering bidirectional reflection distribution function is used for interpolation. Interpolation is performed on the forward scattering and backscattering intervals. In the forward scattering interval, the bidirectional reflection distribution function of forward scattering is used for interpolation, and in other intervals, the bidirectional reflection distribution function of backscattering is used for interpolation. The bidirectional reflection distribution function is based on | -sin | is the independent variable, where, The scattering angle is... The angle of specular reflection; The process of interpolating each of the bidirectional reflection distribution functions according to multiple different interpolation schemes to obtain the interpolation results of each interpolation scheme includes: For each of the various interpolation schemes, interpolation with different interpolation densities is performed on each of the bidirectional reflection distribution functions according to the interpolation schemes, so as to obtain the interpolation results of each interpolation scheme under different interpolation densities; The surface scattering characteristic data whose differences between the corresponding simulation results and the measurement results meet the preset result difference conditions are selected as the surface scattering characteristic data of the optical system, including: Surface scattering characteristic data whose differences between the simulation results and the measurement results satisfy a preset result difference condition are selected, and the surface scattering characteristic data whose interpolation density satisfies a preset interpolation density condition are used as the surface scattering characteristic data of the optical system. The measurement results and the simulation results include point source transmittance; The acquisition of the bidirectional reflectance distribution function of the matte coating sample at multiple incident angles includes: Obtain the bidirectional reflection distribution function of the matte coating sample at multiple incident angles within [0°, 75°] and with a scattering angle range of [-80°, 80°].

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method of any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-6.

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