stray light suppression capability testing system

Abstract

This invention belongs to the field of stray light suppression, and particularly relates to a stray light suppression capability testing system, comprising: a stray light simulation source for emitting stray light, and stray light incident angle adjustment module, pose adjustment module, irradiation detection module, environmental detection module, background extinction cavity, and stray light suppression module respectively disposed within an optical dark chamber. The stray light incident angle adjustment module is used to adjust the angle of stray light entering the optical dark chamber; the pose adjustment module is used to adjust the pose of the optical system under test; the irradiation detection module is used to measure the irradiance at the light inlet of the optical system under test; the environmental detection module is used to measure the ambient stray light energy within the field of view of the optical system under test; the background extinction cavity is used to absorb residual stray light within the field of view of the optical system under test; and the stray light suppression module is used to absorb residual stray light outside the field of view of the optical system under test. This invention, through systematic and innovative design, comprehensively improves the accuracy, efficiency, and reliability of stray light suppression capability testing of optical systems.

Description

Technical Field

[0001] This invention belongs to the field of stray light suppression technology, and in particular relates to a stray light suppression capability testing system. Background Technology

[0002] High-sensitivity optical systems, especially optoelectronic measurement equipment used in aerospace attitude measurement, astronomical observation, Earth remote sensing, and laser communication, are highly susceptible to interference from stray light. These systems typically need to detect extremely weak target signals in the presence of strong background light sources (such as the sun or moon). Therefore, stray light suppression capability is one of their core performance indicators, directly determining the signal-to-noise ratio, detection accuracy, and operational reliability of the equipment in complex lighting environments. To fully verify and optimize this performance during the ground-based development phase, a dedicated testing system capable of accurately simulating the space stray light environment and quantitatively evaluating the system's suppression capability must be constructed.

[0003] Currently, ground-based testing methods for suppressing stray light in optical systems generally face the following technical challenges:

[0004] First, the background noise control of the testing environment is insufficient. Ideally, testing should be conducted against an extremely dark background, similar to space, to accurately assess the contribution of stray light itself. However, existing testing equipment often struggles to effectively shield external stray light and suppress multiple reflections within the device, resulting in high background irradiance. This leads to excessive environmental noise in the measurement results, ultimately underestimating the true stray light suppression capability of the system under test and affecting the accuracy of performance evaluation.

[0005] Secondly, the simulation of stray light incident angles lacks flexibility. The impact of stray light on the system is closely related to its incident angle, requiring the test system to accurately simulate different incident angle conditions over a wide range. Existing technologies mostly achieve angle changes by rotating the bulky device under test (DUT) or moving a large light source simulator. The former is limited by the load-bearing capacity and rotation range of the DUT's mounting interface, while the latter suffers from difficulty in adjustment, low accuracy, and poor stability due to the large size and weight of the light source system.

[0006] Third, the incident beam and the system under test are not accurately matched. Most tests use a parallel beam with a fixed aperture. When the incident angle of stray light is changed, the size and shape of the spot of light illuminating the light inlet of the system under test may change. Simulated stray light that does not enter the light inlet of the system under test may enter the environment, generating redundant stray light, which will affect the consistency of the test.

[0007] Fourth, key parameters at the light inlet are missing. Quantitative assessment of stray light suppression capability relies on the precise irradiance value at the light inlet of the system. Existing testing methods typically use the theoretical output value of the light source directly or through simple calculations, failing to measure the actual irradiance at the light inlet of the device under test in real time and in situ. Due to uncertainties such as optical path attenuation and beam shaping losses, there is a deviation between the theoretical and actual values, which directly affects the accuracy of the final suppression capability calculation.

[0008] In summary, existing testing methods have limitations in environmental noise control, incident angle simulation flexibility, beam matching accuracy, and real-time measurement of key parameters, making it difficult to meet the growing demand for testing and verification of stray light suppression performance in high-precision, high-reliability optical systems. Therefore, there is an urgent need to develop a comprehensive testing system that can provide ultra-low background noise, achieve wide-range and high-precision stray light incident angle simulation, possess dynamic beam matching capabilities, and accurately measure irradiance at the light inlet in real time. This system would improve the realism, accuracy, and efficiency of testing, providing crucial technical support for the performance verification and quality assurance of various high-sensitivity optical systems. Summary of the Invention

[0009] In view of this, the present invention aims to provide a stray light suppression capability testing system to solve the problems of low testing accuracy caused by insufficient background irradiance, poor flexibility in simulating stray light incident angle, excessive stray light introduced into the system, and lack of real-time measurement of the true irradiance at the light inlet of the star sensor in existing testing methods.

[0010] To achieve the above objectives, the technical solution created by this invention is implemented as follows:

[0011] A stray light suppression capability testing system, comprising:

[0012] A stray light simulation source, used to emit a beam of light to simulate stray light;

[0013] An optical dark box is positioned in the direction of emission from a stray light simulation source, and an matting film is coated on the inner wall of the optical dark box.

[0014] A variable aperture is positioned on the optical dark box directly opposite the stray light simulation source;

[0015] A stray light incident angle adjustment module, which is located inside the optical dark box, is used to adjust the angle of stray light entering the optical dark box;

[0016] The pose adjustment module is located inside the optical dark box, and the optical system under test is mounted on the pose adjustment module. The pose adjustment module is used to adjust the five degrees of freedom of the optical system under test.

[0017] The irradiance detection module, which is set inside the optical dark box, is used to measure the irradiance at the light inlet of the optical system under test;

[0018] An environmental detection module, located inside an optical dark box, is used to measure the energy of stray ambient light within the field of view of the optical system under test.

[0019] The background extinction cavity, which is located inside the optical dark box, is used to absorb residual stray light in the field of view of the optical system under test;

[0020] A stray light suppression module, which is located inside an optical dark box, is used to absorb residual stray light outside the field of view of the optical system under test;

[0021] The computer is used to control the variable aperture, stray light incident angle adjustment module, optical system under test, pose adjustment module, irradiation detection module, and environmental detection module, respectively.

[0022] Furthermore, the stray light incident angle adjustment module includes a reflection component, a stray light X-axis linear displacement mechanism, and a stray light Z-axis rotation mechanism. The reflection component is mounted on the stray light Z-axis rotation mechanism, and the stray light Z-axis rotation mechanism is mounted on the stray light X-axis linear displacement mechanism. The stray light X-axis linear displacement mechanism is set along the optical axis direction of the stray light simulation source.

[0023] Furthermore, the pose adjustment module is located on one side of the stray light incident angle adjustment module and is not coaxial with it. The pose adjustment module includes a linear displacement mechanism for the X-axis under test, a linear displacement mechanism for the Y-axis under test, a linear displacement mechanism for the Z-axis under test, a rotation mechanism for the Z-axis under test, and a pitch mechanism for the Y-axis under test. The optical system under test is mounted on the rotation mechanism for the Z-axis under test, the rotation mechanism for the Z-axis under test is mounted on the pitch mechanism for the Y-axis under test, the pitch mechanism for the Y-axis under test is mounted on the linear displacement mechanism for the Y-axis under test, the linear displacement mechanism for the Y-axis under test is mounted on the linear displacement mechanism for the Z-axis under test, and the linear displacement mechanism for the Z-axis under test is mounted on the linear displacement mechanism for the X-axis under test. The linear displacement mechanism for the X-axis under test is set along the optical axis direction of the stray light simulation source, and the linear displacement mechanism for the Y-axis under test is horizontally perpendicular to the linear displacement mechanism for the X-axis under test.

[0024] Furthermore, the irradiation detection module includes a radiation detection component and a radiation Y-axis linear displacement mechanism. The radiation detection component is mounted on the radiation Y-axis linear displacement mechanism, which is mounted on the Z-axis rotation mechanism to be measured. The radiation Y-axis linear displacement mechanism and the Z-axis linear displacement mechanism to be measured are arranged in parallel.

[0025] Furthermore, the environmental detection module is positioned between the pose adjustment module and the background extinction cavity. The environmental detection module includes a weak light illuminance detection component, a detection X-axis linear displacement mechanism, a detection Y-axis linear displacement mechanism, a detection Z-axis linear displacement mechanism, and a detection Z-axis rotation mechanism. The weak light illuminance detection component is mounted on the detection Z-axis rotation mechanism, the detection Z-axis rotation mechanism is mounted on the detection Z-axis linear displacement mechanism, the detection Z-axis linear displacement mechanism is mounted on the detection Y-axis linear displacement mechanism, and the detection Y-axis linear displacement mechanism is mounted on the detection X-axis linear displacement mechanism. The detection X-axis linear displacement mechanism is positioned along the optical axis of the stray light simulation source, and the detection Y-axis linear displacement mechanism is horizontally perpendicular to the detection X-axis linear displacement mechanism.

[0026] Furthermore, the background extinction cavity is a hollow cavity structure with an entrance, and the inner wall of the hollow cavity is coated with a light-absorbing material. The extinction ratio of the background extinction cavity is greater than 99.8%.

[0027] Furthermore, the ratio of the emitted luminous flux to the incident luminous flux of the background extinction cavity satisfies the following formula:

[0028] ;

[0029] in, This is the ratio of the entrance area to the total inner wall area of ​​the background matting cavity. The total area of ​​the inner wall of the background matting cavity. ; The inlet area of ​​the background matting cavity. The reflectance of the inner wall of the background extinction cavity.

[0030] Furthermore, the stray light suppression module is a honeycomb light-absorbing plate fixed on the inner wall of the optical dark box, and the surface of the honeycomb light-absorbing plate has a pyramidal structure.

[0031] Furthermore, the angle between the stray light axis reflected by the reflective component and the optical axis of the optical system under test is defined as the stray light incident angle θ, which is maintained within the range of 20°-90°.

[0032] Furthermore, the incident angle θ of the stray light satisfies the following formula:

[0033] ;

[0034] in, The distance between the center of the reflective component and the end of the stray light simulation source near the stray light X-axis linear displacement mechanism; The distance between the center of the optical system under test and the end of the X-axis linear displacement mechanism under test that is closest to the stray light simulation source is denoted as . ; The center distance between the X-axis linear displacement mechanism to be tested and the stray light X-axis linear displacement mechanism is defined; the end of the stray light X-axis linear displacement mechanism near the stray light simulation source is aligned with the end of the X-axis linear displacement mechanism to be tested near the stray light simulation source.

[0035] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0036] 1. The stray light suppression capability testing system integrates an optical darkroom with an internally coated ultra-high absorptivity extinction film, a background extinction cavity, and a stray light suppression module, constructing a multi-layered, three-dimensional stray light suppression system. This stray light suppression system effectively isolates external stray light and strongly absorbs unexpected reflected and scattered light generated within the stray light suppression capability testing system, stabilizing the test background illuminance at 10. -8 The ultra-low level below lx highly simulates the dim environment of deep space, fundamentally avoiding the problem of underestimating stray light suppression capability due to excessive background noise, and significantly improving the accuracy and reliability of the test.

[0037] 2. By employing an independent stray light incident angle adjustment module, the beam deflection is achieved on a fixed optical path through a reflective component and a linear and rotating mechanism, thereby changing the stray light incident angle θ. This invention eliminates the need to move bulky analog light sources or rotate the optical system under test; only the position and angle of the reflective component need to be controlled to achieve stepless and precise adjustment of the stray light incident angle within the range of 20°-90°. This not only simplifies operation and improves adjustment efficiency but also ensures the reference stability of the system's optical axis, laying the foundation for highly repeatable testing.

[0038] 3. By introducing a variable aperture in the optical path and adjusting its aperture in real time, it is possible to ensure that the size of the light spot illuminating the optical system under test after reflection remains precisely consistent with the aperture diameter. This dynamic matching mechanism avoids the over-illumination or under-illumination problems that may occur with traditional fixed-aperture beams at different incident angles, minimizes the introduction of invalid stray light in non-aperture areas, reduces system noise, and improves the signal-to-noise ratio of the test signal.

[0039] 4. During testing, the irradiance detection module can quickly move the detection component to the light inlet of the optical system under test for in-situ measurement, directly obtaining the true irradiance of stray light at the light inlet. This design completely changes the previous indirect measurement method that relied on the theoretical output value of the light source for conversion, eliminating errors introduced by uncertainties such as optical path attenuation and reflection loss. It provides the most critical and accurate input data for subsequent calculation of point source transmittance, greatly improving the accuracy of the final test results.

[0040] 5. The environmental detection module can output the amount of residual stray light in real time, enabling convenient detection of redundant stray light in the environment and increasing reliability.

[0041] 6. The entire stray light suppression capability testing system is centrally controlled and data processed by a computer system, realizing coordinated control of the variable aperture, motion mechanism, and various detection modules, as well as automatic data acquisition and processing. This integrated design not only simplifies the testing process and reduces human error, but also enables rapid and continuous automated testing at multiple angles (different stray light incident angles θ), directly outputting PST-θ curves for comprehensive performance evaluation. Examples show that this stray light suppression capability testing system exhibits high repeatability and reliable results, providing an efficient and powerful ground-based testing platform for performance verification and quality control of the optical system under test. Attached Figure Description

[0042] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0043] Figure 1 A schematic diagram of the stray light suppression capability testing system described in the embodiments of the present invention;

[0044] Figure 2 A schematic diagram of the stray light incident angle adjustment module described in an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the pose adjustment module described in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the structure of the environmental detection module described in an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached figures: 1. Stray light simulation source; 2. Variable aperture; 3. Optical dark box; 4. Stray light incident angle adjustment module; 5. Optical system under test; 6. Pose adjustment module; 7. Irradiation detection module; 8. Environmental detection module; 9. Background extinction cavity; 10. Stray light suppression module; 11. Support frame; 12. Computer; 41. Reflection component; 42. Stray light X-axis linear displacement mechanism; 43. Stray light Z-axis rotation mechanism; 61. Tested Z-axis rotation mechanism; 62. Tested Y-axis pitch mechanism; 63. Tested Y-axis linear displacement mechanism; 64. Tested Z-axis linear displacement mechanism; 65. Tested X-axis linear displacement mechanism; 71. Radiation detection component; 72. Radiation Y-axis linear displacement mechanism; 81. Low light illuminance detection component; 82. Detection X-axis linear displacement mechanism; 83. Detection Y-axis linear displacement mechanism; 84. Detection Z-axis linear displacement mechanism; 85. Detection Z-axis rotation mechanism. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] The following will refer to Figures 1-4 The invention will be described in detail with reference to the embodiments.

[0053] like Figure 1 As shown, this invention provides a stray light suppression capability testing system, including a stray light simulation source 1, a variable aperture 2, an optical dark box 3, a stray light incident angle adjustment module 4, a pose adjustment module 6, an irradiation detection module 7, an environmental detection module 8, a background extinction cavity 9, a stray light suppression module 10, a support frame 11, and a computer 12; wherein, the stray light simulation source 1 is used to emit a parallel beam to simulate stray light; the optical dark box 3 is set in the emission direction of the stray light simulation source 1, and the inner wall of the optical dark box 3 is coated with an extinction film with a reflectivity ≤1%, thereby providing a reflectivity better than 10% for the optical system 5 under test.-8 The ultra-low illumination darkness environment of lx effectively isolates external stray light interference. A variable aperture 2 is positioned on the optical dark box 3 directly opposite the stray light simulation source 1. Stray light emitted from the simulation source 1 enters the optical dark box 3 through the variable aperture 2. The aperture of the variable aperture 2 is adjustable, thereby controlling the diameter of the beam entering the optical dark box 3 to match the entrance size of the optical system under test 5. A stray light incident angle adjustment module 4 is located inside the optical dark box 3 to adjust the angle of the stray light entering the optical dark box 3. A pose adjustment module 6 is located inside the optical dark box 3 and has five degrees of freedom. The optical system under test 5 is mounted on the pose adjustment module 6, and the pose adjustment module 6 enables five-degree-of-freedom adjustment. An irradiance detection module 7 is located inside the optical dark box 3 to measure the irradiance at the entrance of the optical system under test 5. An environmental detection module 8 is located inside the optical dark box 3 to measure the environmental stray light energy within the field of view of the optical system under test 5. A background extinction cavity 9 is located inside the optical dark box 3 to absorb... The optical system under test (OST) 5 receives residual stray light within its field of view, providing a very weak light observation background for its testing. The stray light suppression module 10, located inside the optical dark box 3, absorbs residual stray light outside the OST's field of view. The computer 12, located outside the optical dark box 3, serves as the control and data processing center for the entire testing system. It is connected via signal lines to the variable aperture 2, stray light incident angle adjustment module 4, OST 5, pose adjustment module 6, irradiation detection module 7, and environmental detection module 8. The computer 12 sends control commands to control the aperture of the variable aperture 2, the stray light incident angle adjustment module 4, the pose adjustment module 6, the irradiation detection module 7, and the environmental detection module 8 to work collaboratively. It also receives and processes the measurement data from these modules to accurately output the stray light suppression capability test results for OST 5.

[0054] The optical axis of the parallel beam is defined as system optical axis I, and the principal optical axis of the detector of the optical system under test 5 is defined as system optical axis II. System optical axis I and system optical axis II are parallel and equidistant from the bottom of the optical dark box 3 (i.e., system optical axis I and system optical axis II are at the same height). The plane in which system optical axis I and system optical axis II are located is defined as the XY plane. The direction pointed to by system optical axis I is the X-axis, the direction perpendicular to the X-axis in the XY plane is the Y-axis, and the direction perpendicular to both the X-axis and the Y-axis is the Z-axis.

[0055] The variable aperture 2 is set at the position of the successor optical path of the stray light simulation source 1 along the optical axis I of the system, and the optical axis of the variable aperture 2 coincides with the optical axis I of the system.

[0056] The aperture of the variable aperture 2 is continuously adjustable. The size of the aperture is controlled by the computer 12, thereby precisely controlling the light flux entering the optical dark box 3. This ensures that the diameter of the light spot after reflection by the stray light incident angle adjustment module 4 is always equal to the diameter of the light inlet of the optical system under test 5, so as to minimize the introduction of invalid stray light.

[0057] An entrance aperture is provided on the side of the optical dark box 3 facing the stray light simulation source 1, and the geometric center of the entrance aperture is located on the system optical axis I. A variable aperture 2 is installed inside the entrance aperture. In order to ensure that the geometric center of the entrance aperture coincides with the system optical axis I, the optical dark box 3 is mounted on a support frame 11. The support frame 11 can support and level the entire optical dark box 3, ensuring that the geometric center of the entrance aperture always coincides with the system optical axis I, thus ensuring the stability of the optical path reference.

[0058] like Figure 2 As shown, the stray light incident angle adjustment module 4 is disposed inside the optical dark box 3 and located at the position following the light entrance aperture along the system optical axis I. The stray light incident angle adjustment module 4 includes a reflection component 41, a stray light X-axis linear displacement mechanism 42, and a stray light Z-axis rotation mechanism 43. The reflection component 41 is mounted on the top of the stray light Z-axis rotation mechanism 43, which drives the reflection component 41 to rotate around the Z-axis. The bottom end of the stray light Z-axis rotation mechanism 43 is mounted on the slider of the stray light X-axis linear displacement mechanism 42, which is set along the X-axis. The stray light X-axis linear displacement mechanism 42 drives the reflection component 41 to move along the X-axis. Regardless of whether the reflection component 41 moves along the X-axis or rotates around the Z-axis, the reflection geometric center of the reflection component 41 is ultimately located on the system optical axis I.

[0059] The optical axis of the light-transmitting aperture of the variable aperture 2, the geometric center of the light-incident aperture, and the reflection geometric center of the reflective component 41 all coincide with the optical axis I of the system.

[0060] The angle between the stray light axis reflected by the reflector 41 and the system optical axis II is defined as the stray light incident angle θ, which is controlled within the range of 20°-90° by the stray light incident angle adjustment module 4.

[0061] like Figure 3As shown, the pose adjustment module 6 is located on one side of the stray light incident angle adjustment module 4 and is not coaxial with it. The pose adjustment module 6 includes a Z-axis rotation mechanism 61 to be tested, a Y-axis pitch mechanism 62 to be tested, a Y-axis linear displacement mechanism 63 to be tested, a Z-axis linear displacement mechanism 64 to be tested, and an X-axis linear displacement mechanism 65 to be tested. The optical system 5 to be tested is mounted on the top of the Z-axis rotation mechanism 61 to be tested. The bottom of the Z-axis rotation mechanism 61 to be tested is mounted on the top of the Y-axis pitch mechanism 62 to be tested. The bottom of the Y-axis pitch mechanism 62 to be tested is mounted on the slider of the Y-axis linear displacement mechanism 63 to be tested. The slide rail of the Y-axis linear displacement mechanism 63 to be tested is mounted on the slider of the Z-axis linear displacement mechanism 64 to be tested. The slide rail of the Z-axis linear displacement mechanism 64 to be tested is mounted on the slider of the X-axis linear displacement mechanism 65 to be tested. The slide rail of the X-axis linear displacement mechanism 65 to be tested is fixed to the bottom of the optical dark box 3.

[0062] The slide rail of the X-axis linear displacement mechanism 65 to be tested is set along the X-axis direction, the slide rail of the Y-axis linear displacement mechanism 63 to be tested is set along the Y-axis direction, and the Z-axis rotation mechanism 61 to be tested is set along the Z-axis direction.

[0063] The end of the X-axis linear displacement mechanism 65 under test, which is close to the stray light simulation source 1, is aligned with the end of the stray light X-axis linear displacement mechanism 42, which is close to the stray light simulation source 1.

[0064] The optical system under test (OST) 5 is rotated around the Z-axis via the Z-axis rotation mechanism 61, pitched along the Y-axis via the Y-axis pitch mechanism 62, moved along the Y-axis via the Y-axis linear displacement mechanism 63, moved along the Z-axis via the Z-axis linear displacement mechanism 64, and moved along the X-axis via the X-axis linear displacement mechanism 65. The OST 5 achieves five-degree-of-freedom adjustment via the pose adjustment module 6, thereby enabling precise positioning and attitude simulation of the OST 5 in space.

[0065] like Figure 3 As shown, the irradiation detection module 7 is mounted on the pose adjustment module 6 and is positioned at the rear of the optical system under test 5 along the system optical axis II during operation. The irradiation detection module 7 includes a radiation detection component 71 and a radiation Y-axis linear displacement mechanism 72. The radiation detection component 71 is mounted on the radiation Y-axis linear displacement mechanism 72, which is mounted on the Z-axis rotation mechanism 61 under test along the Y-axis. The radiation Y-axis linear displacement mechanism 72 drives the radiation detection component 71 to move along the Y-axis, so that the detector center axis of the radiation detection component 71 is coaxial with the system optical axis II and closely attached to the optical system under test 5, thereby realizing the real-time measurement of the irradiance at the light entrance of the optical system under test 5.

[0066] like Figure 4As shown, the environmental detection module 8 is located at the rear of the optical system 5 under test along the optical axis II. The environmental detection module 8 includes a low light intensity detection component 81, a detection X-axis linear displacement mechanism 82, a detection Y-axis linear displacement mechanism 83, a detection Z-axis linear displacement mechanism 84, and a detection Z-axis rotation mechanism 85. The low light intensity detection component 81 is mounted on the top of the detection Z-axis rotation mechanism 85, and the bottom of the detection Z-axis rotation mechanism 85 is mounted on the slider of the detection Z-axis linear displacement mechanism 84. The slide rail of the detection Z-axis linear displacement mechanism 84 is mounted on the slider of the detection Y-axis linear displacement mechanism 83 along the Y-axis direction, and the slide rail of the detection Y-axis linear displacement mechanism 83 is mounted on the slider of the detection X-axis linear displacement mechanism 82. The detection X-axis linear displacement mechanism 82 is fixed to the bottom of the optical dark box 3 along the optical axis II.

[0067] The weak light intensity detection component 81 is moved along the X-axis by the X-axis linear displacement mechanism 82, along the Y-axis by the Y-axis linear displacement mechanism 83, along the Z-axis by the Z-axis linear displacement mechanism 84, and rotated around the Z-axis by the Z-axis rotation mechanism 85. Through the multi-degree-of-freedom motion of the weak light intensity detection component 81, the ambient stray light energy within the field of view of the optical system under test 5 is measured.

[0068] Background extinction cavity 9 is located at the rear of environmental detection module 8 along the optical axis II of the system. Background extinction cavity 9 is a hollow cavity structure with an entrance. The inner wall of the hollow cavity is coated with light-absorbing material. The extinction ratio of background extinction cavity 9 is >99.8% to absorb residual stray light in the field of view of the optical system under test 5, providing the optical system under test 5 with an extremely low reflection and almost absolute darkness as an observation background.

[0069] The ratio of the emitted luminous flux to the incident luminous flux of the background extinction cavity 9 satisfies the following formula:

[0070] ;

[0071] in, The ratio of the entrance area to the total inner wall area of ​​the background matting cavity 9 is given. The total area of ​​the inner wall of the background matting cavity 9. ; The inlet area of ​​background matting cavity 9. The reflectance of the inner wall of the background extinction cavity 9 is given.

[0072] The detection optical axis of the weak light illuminance detection component 81 and the geometric center of the background extinction cavity 9 are both coincident with the system optical axis II.

[0073] A stray light suppression module 10 is located in the stray light concentration area within the optical dark chamber 3. The stray light suppression module 10 is a honeycomb-shaped light-absorbing plate fixed to the inner wall of the optical dark chamber 3. The porous structure of the honeycomb-shaped light-absorbing plate can absorb residual stray light outside the field of view of the optical system 5 under test. The surface of the honeycomb-shaped light-absorbing plate has a pyramidal structure, which allows redundant stray light to be reflected multiple times between the pyramidal structures, making the absorption of redundant stray light by the honeycomb-shaped light-absorbing plate more thorough and avoiding secondary stray light interference. The honeycomb-shaped light-absorbing plates are arranged in an array on the inner wall of the optical dark chamber 3. The honeycomb-shaped light-absorbing plates can be 3D printed or purchased as finished products.

[0074] In a specific example of the present invention, the stray light simulation source 1 adopts a radiant intensity of 1360 W / m². 2 A customized light source with a spot diameter of Φ100mm, a divergence angle of 1°, a spectral matching degree of Class A, and an irradiance non-uniformity of ≤2%.

[0075] The reflective component 41 uses a customized planar reflector that meets the following requirements: parallelism deviation ≤ 1′, surface accuracy λ / 2-λ / 4, reflectivity ≥ 95%, and surface quality 60-40.

[0076] The stray light X-axis linear displacement mechanism 42 adopts the product model PT-GD140G-1500.

[0077] The stray light Z-axis rotation mechanism 43 uses a product with model number PT-GD220H.

[0078] The Z-axis rotation mechanism 61 under test is a product with model number PT-GD95A120.

[0079] The Y-axis pitch mechanism 62 under test is a product with model number PT-GD145.

[0080] The Y-axis linear displacement mechanism 63 to be tested is a product with model number PT-GD140G-200.

[0081] The Z-axis linear displacement mechanism 64 under test is a product with model number PT-GD402.

[0082] The X-axis linear displacement mechanism 65 under test is a product with model number PT-GD140G-500.

[0083] The radiation detection component 71 uses the PP120-200 model.

[0084] The radial Y-axis linear displacement mechanism 72 uses a product with model number PP120-150.

[0085] The low light illuminance detection component 81 uses the product model KLL-04.

[0086] The X-axis linear displacement detection mechanism 82 uses the PT-GD140G-500 model.

[0087] The Y-axis linear displacement detection mechanism 83 uses a product with model number GD140G-300.

[0088] The Z-axis linear displacement detection mechanism 84 uses a product with model number PT-GD2513.

[0089] The Z-axis rotation mechanism 85 is tested using a product with model number PX110-100.

[0090] The measurement procedure for the stray light suppression capability testing system is as follows:

[0091] Step S1: Level the optical dark box 3 using the support frame 11 to ensure that the geometric center of the light entrance aperture coincides with the optical axis I of the system.

[0092] Step S2: Start computer 12, establish signal connections with each module and complete initialization, verify the motion accuracy of stray light incident angle adjustment module 4 and pose adjustment module 6, and confirm that the detection functions of irradiation detection module 7 and environmental detection module 8 are normal.

[0093] Step S3: Set the stray light incident angle θ according to the test requirements.

[0094] Step S4: Calculate the displacement that the reflective component 41 needs to move according to the formula for calculating the stray light incident angle θ. and .

[0095] The formula for calculating the incident angle θ of stray light is:

[0096] ;

[0097] in, The distance between the center of the reflective component 41 and the end of the stray light X-axis linear displacement mechanism 42 near the stray light simulation source 1; The distance between the center of the optical system 5 under test and the end of the X-axis linear displacement mechanism 65 under test that is close to the stray light simulation source 1, and ; The center distance between the X-axis linear displacement mechanism 65 to be measured and the stray X-axis linear displacement mechanism 42 is denoted as 65.

[0098] Step S5: Adjust the position and angle of the reflective component 41 by using the stray light X-axis linear displacement mechanism 42 and the stray light Z-axis rotation mechanism 43 to make the stray light incident angle θ reach the set value.

[0099] Step S6: Obtain the entrance diameter parameter of the optical system under test 5 through computer 12, control the aperture of the variable aperture 2 to ensure that the diameter of the light spot after reflection by the reflective component 41 matches the entrance diameter of the optical system under test 5, and minimize the introduction of invalid stray light.

[0100] Step S7: Using the radiation Y-axis linear displacement mechanism 72, move the radiation detection component 71 to the rear position of the optical system under test 5 along the system optical axis II, so that the radiation detection component 71 is coaxial with the system optical axis II and in close contact with the optical system under test 5, and measure the irradiance E at the light entrance of the optical system under test 5 in real time. i (θ) is transmitted to computer 12, and the ambient stray light energy within the field of view of the optical system under test 5 is measured by the position and angle of the low light illuminance detection component 81 to ensure that the background illuminance meets 10. -8 Testing requirements below lx.

[0101] Step S8: The optical system under test 5 acquires the image plane irradiance E. d (θ) and uploaded to computer 12, which calculates the stray light suppression capability, i.e., the point source transmittance (PST) of the optical system 5 under test. PST is calculated using the following formula:

[0102] ;

[0103] Step S9: Repeat steps S3 to S8 above, select multiple different stray light incident angles θ in the range of 20°-90° for testing, record the PST value at each stray light incident angle θ, plot the PST-θ curve, and comprehensively evaluate the stray light suppression capability of the optical system 5 under test.

[0104] In actual testing, when θ = 45°, the measured PST = 2.21 × 10⁻⁶. -7 With a repeatability standard deviation of less than 5%, the test accuracy and reliability are significantly improved, ensuring that the test results can truly reflect the stray light suppression performance of the optical system 5 under test.

[0105] The optical system 5 to be tested in this invention can be a star sensor, remote sensing camera, space telescope, navigation optical payload, or other equipment that needs to operate in the complex light environment of space.

[0106] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0107] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A stray light suppression capability testing system, characterized in that, include: A stray light simulation source, used to emit a beam of light to simulate stray light; An optical dark box is positioned in the direction of emission from a stray light simulation source, and an matting film is coated on the inner wall of the optical dark box. A variable aperture is positioned on the optical dark box directly opposite the stray light simulation source; A stray light incident angle adjustment module, which is located inside the optical dark box, is used to adjust the angle of stray light entering the optical dark box; The pose adjustment module is located inside the optical dark box, and the optical system under test is mounted on the pose adjustment module. The pose adjustment module is used to adjust the five degrees of freedom of the optical system under test. The irradiance detection module, which is set inside the optical dark box, is used to measure the irradiance at the light inlet of the optical system under test; An environmental detection module, located inside an optical dark box, is used to measure the energy of stray ambient light within the field of view of the optical system under test. The background extinction cavity, which is located inside the optical dark box, is used to absorb residual stray light in the field of view of the optical system under test; A stray light suppression module, which is located inside an optical dark box, is used to absorb residual stray light outside the field of view of the optical system under test; The computer is used to control the variable aperture, stray light incident angle adjustment module, optical system under test, pose adjustment module, irradiation detection module, and environmental detection module, respectively.

2. The stray light suppression capability testing system according to claim 1, characterized in that, The stray light incident angle adjustment module includes a reflection component, a stray light X-axis linear displacement mechanism, and a stray light Z-axis rotation mechanism. The reflection component is mounted on the stray light Z-axis rotation mechanism, and the stray light Z-axis rotation mechanism is mounted on the stray light X-axis linear displacement mechanism. The stray light X-axis linear displacement mechanism is set along the optical axis direction of the stray light simulation source.

3. The stray light suppression capability testing system according to claim 2, characterized in that, The pose adjustment module is located on one side of the stray light incident angle adjustment module and is not coaxial with it. The pose adjustment module includes a linear displacement mechanism for the X-axis under test, a linear displacement mechanism for the Y-axis under test, a linear displacement mechanism for the Z-axis under test, a rotation mechanism for the Z-axis under test, and a pitch mechanism for the Y-axis under test. The optical system under test is mounted on the rotation mechanism for the Z-axis under test, the rotation mechanism for the Z-axis under test is mounted on the pitch mechanism for the Y-axis under test, the pitch mechanism for the Y-axis under test is mounted on the linear displacement mechanism for the Y-axis under test, the linear displacement mechanism for the Y-axis under test is mounted on the linear displacement mechanism for the Z-axis under test, and the linear displacement mechanism for the Z-axis under test is mounted on the linear displacement mechanism for the X-axis under test. The linear displacement mechanism for the X-axis under test is set along the optical axis direction of the stray light simulation source, and the linear displacement mechanism for the Y-axis under test is horizontally perpendicular to the linear displacement mechanism for the X-axis under test.

4. The stray light suppression capability testing system according to claim 3, characterized in that, The irradiation detection module includes a radiation detection component and a radiation Y-axis linear displacement mechanism. The radiation detection component is mounted on the radiation Y-axis linear displacement mechanism, which is mounted on the Z-axis rotation mechanism to be measured. The radiation Y-axis linear displacement mechanism and the Z-axis linear displacement mechanism to be measured are arranged in parallel.

5. The stray light suppression capability testing system according to claim 1, characterized in that, The environmental detection module is positioned between the pose adjustment module and the background extinction cavity. The environmental detection module includes a weak light illuminance detection component, a detection X-axis linear displacement mechanism, a detection Y-axis linear displacement mechanism, a detection Z-axis linear displacement mechanism, and a detection Z-axis rotation mechanism. The weak light illuminance detection component is mounted on the detection Z-axis rotation mechanism, the detection Z-axis rotation mechanism is mounted on the detection Z-axis linear displacement mechanism, the detection Z-axis linear displacement mechanism is mounted on the detection Y-axis linear displacement mechanism, and the detection Y-axis linear displacement mechanism is mounted on the detection X-axis linear displacement mechanism. The detection X-axis linear displacement mechanism is positioned along the optical axis of the stray light simulation source, and the detection Y-axis linear displacement mechanism is horizontally perpendicular to the detection X-axis linear displacement mechanism.

6. The stray light suppression capability testing system according to claim 1, characterized in that, The background extinction cavity is a hollow cavity structure with an entrance. The inner wall of the hollow cavity is coated with a light-absorbing material, and the extinction ratio of the background extinction cavity is greater than 99.8%.

7. The stray light suppression capability testing system according to claim 6, characterized in that, The ratio of the emitted luminous flux to the incident luminous flux of the background extinction cavity satisfies the following formula: ； in, This is the ratio of the entrance area to the total inner wall area of ​​the background matting cavity. The total area of ​​the inner wall of the background matting cavity. ; The inlet area of ​​the background matting cavity. The reflectance of the inner wall of the background extinction cavity is given.

8. The stray light suppression capability testing system according to claim 1, characterized in that, The stray light suppression module is a honeycomb light-absorbing plate fixed on the inner wall of the optical dark box. The surface of the honeycomb light-absorbing plate has a pyramidal structure.

9. The stray light suppression capability testing system according to claim 3, characterized in that, The angle between the stray light optical axis reflected by the reflective component and the optical axis of the optical system under test is defined as the stray light incident angle θ, which is kept within the range of 20°-90°.

10. The stray light suppression capability testing system according to claim 9, characterized in that, The incident angle θ of stray light satisfies the following formula: ； in, The distance between the center of the reflective component and the end of the stray light simulation source near the stray light X-axis linear displacement mechanism; The distance between the center of the optical system under test and the end of the X-axis linear displacement mechanism under test that is closest to the stray light simulation source is denoted as . ; The center distance between the X-axis linear displacement mechanism to be tested and the stray light X-axis linear displacement mechanism is defined; the end of the stray light X-axis linear displacement mechanism near the stray light simulation source is aligned with the end of the X-axis linear displacement mechanism to be tested near the stray light simulation source.

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