Photoelectric imaging detector multi-angle damage real-time measurement system and method

Abstract

The invention belongs to the technical field of laser damage measurement, and relates to a multi-angle damage real-time measurement system and method for a photoelectric imaging detector. The measuring system comprises a laser emitting unit, a first incident unit, a second incident unit, a detection light source, a measuring unit and a controller. The laser emission unit is used for emitting laser beams with adjustable energy and types, the laser beams irradiate the same preset area on the photoelectric imaging detector along a light path constructed by the first incidence unit and a light path constructed by the second incidence unit, and the energy of the laser beams is equal; the detection light source enables the photoelectric imaging detector to be controllably in an illumination working condition or a non-illumination working condition; the measuring unit is used for measuring a damage image output by the photoelectric imaging detector, laser spot energy distribution characteristics and a surface damage morphology image of the photoelectric imaging detector; and the controller receives the image output by the measuring unit and can send four control instructions. According to the invention, damage measurement under the action of laser multi-angle common irradiation can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of laser damage measurement, and in particular to a real-time multi-angle damage measurement system and method for a photoelectric imaging detector. Background Art

[0002] Photoelectric imaging detectors, such as charge coupled devices (CCD) and complementary metal-oxide-semiconductor (CMOS) image sensors, are small, highly sensitive, and have high resolution. They are widely used in visible light imaging, space remote sensing, and drone reconnaissance. As core components of optical imaging and detection systems, CCD and CMOS detectors are extremely susceptible to laser interference or damage and thus lose their functions. Therefore, the measurement of CCD and CMOS laser damage performance is helpful to strengthen the laser protection of photoelectric imaging detectors.

[0003] The existing technology mainly analyzes the laser damage characteristics of photoelectric imaging detectors through experimental measurements, but the following problems are usually not considered or exist in the experimental settings: ① Only the damage measurement under normal laser incidence is considered, and the damage measurement under the joint irradiation of lasers at multiple angles is not considered; ② For the analysis of laser damage, only the energy change is considered, and the influence of the polarization characteristics of the incident laser is not considered; ③ The laser damage measurement of the photoelectric imaging detector is only carried out under the conditions of illumination or no illumination, and the damage conditions in both cases are not measured simultaneously; ④ Photoelectric imaging detectors such as CCD have vertical and horizontal transfer registers. Therefore, in the experiment, the laser damage measurement of the photoelectric imaging detector should not be carried out in the horizontal or vertical direction as much as possible to prevent mutual interference; ⑤ In the laser damage test, the laser energy and the laser spot are often not measured in real time and at the same time, which affects the accurate measurement of the laser damage energy density; ⑥ The laser beam is often Gaussian, which causes the laser energy to be unevenly distributed on the photoelectric imaging detector, affecting the test of the damage performance.

[0004] In view of this, it is urgent to propose a photoelectric imaging detector laser damage measurement system and method that can solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a real-time measurement system and method for multi-angle damage of a photoelectric imaging detector, which can simultaneously measure the damage of the photoelectric imaging detector under illuminated and unilluminated conditions, and can also simultaneously measure the laser damage energy and the laser spot size, and obtain the image and surface damage morphology of the damaged photoelectric imaging detector in real time, so as to realize multi-angle real-time measurement of the damage of the photoelectric imaging detector.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: In a first aspect, the present invention provides a photoelectric imaging detector multi-angle damage real-time measurement system, comprising: A laser emitting unit, used for emitting a laser beam, wherein the emission energy and beam type of the laser beam are adjustable; A first incident unit, wherein the laser beam irradiates a preset area on the photoelectric imaging detector along a first incident light path constructed by the first incident unit; A second incident unit, wherein the laser beam irradiates a preset area on the photoelectric imaging detector along a second incident light path constructed by the second incident unit; the preset areas irradiated on the photoelectric imaging detector via the first incident light path and the second incident light path are the same, and the laser beam energy is equal; The detection light source can be controlled to be turned on or off, so that the photoelectric imaging detector can be controlled to be in a light-on condition or a no-light condition; A measuring unit, used to measure the damage image output by the photoelectric imaging detector, the energy distribution characteristics of the laser spot, and the damage morphology image on the surface of the photoelectric imaging detector; And a controller receives the image output by the measuring unit, and sends a first control instruction, a second control instruction, a third control instruction and a fourth control instruction, wherein the first control instruction is used to control the laser emitting unit to emit a laser beam, the second control instruction is used to control the opening or closing of the detection light source, the third control instruction is used to control the opening or closing of the shutter, and the fourth control instruction is used to control the movement of a three-dimensional mobile platform, and the three-dimensional mobile platform is used to carry the photoelectric imaging detector.

[0007] As a possible implementation, the laser emitting unit includes, in sequence, the following in the transmission direction of the laser beam: A laser for generating a laser beam; Shutter, used to control the duration of the laser beam; A polarization attenuator, used for attenuating the energy of the laser beam and controlling the beam type, the beam type being one of s-polarized light, p-polarized light, or a combined beam of s-polarized light and p-polarized light; Beam expander collimator, used to compress the spatial divergence angle of the laser beam; and a beam shaper for shaping the expanded and collimated laser beam to obtain a flat-top beam.

[0008] As a possible implementation, the polarization attenuator includes: Polarization beam splitter: the laser beam passing through the shutter enters the polarization beam splitter and is divided into s-polarized light and p-polarized light; S-polarized light path: the s-polarized light is attenuated once and filtered twice on the s-polarized light path before entering the beam combiner through the first reflector; p-polarized light path: p-polarized light directly enters the beam combiner after being attenuated once and filtered twice on the p-polarized light path; A beam combiner combines the received s-polarized light and p-polarized light; The light-emitting reflector receives the combined laser beam and reflects it to the beam expander collimator.

[0009] As a possible implementation, a first polarizer, a first rotating half-wave plate, a second polarizer, a first beam splitter and a first reflector are sequentially arranged on an s-polarized light path along the transmission direction of the s-polarized light; wherein the first polarizer is consistent with the polarization direction of the s-polarized light; the rotation angle of the first rotating half-wave plate can be controllably rotated to change the intensity of the s-polarized light; the polarization direction of the second polarizer is consistent with that of the first polarizer; the s-polarized light passing through the first beam splitter enters the beam combiner through the first reflector, and the s-polarized light reflected by the first beam splitter is received by an energy controller, and the energy controller generates a control instruction for controlling the rotation of the first rotating half-wave plate based on the energy of the received s-polarized light; A second reflector, a third polarizer, a second rotating half-wave plate, a fourth polarizer and a second beam splitter are sequentially arranged on a p-polarized light path along the transmission direction of the p-polarized light; wherein the second reflector reflects the p-polarized light received from the polarization beam splitter to the third polarizer, and the polarization direction of the third polarizer is consistent with the polarization direction of the p-polarized light; the rotation angle of the second rotating half-wave plate is controllably rotated to change the intensity of the p-polarized light; the polarization direction of the fourth polarizer is consistent with the polarization direction of the third polarizer; the p-polarized light reflected by the second beam splitter is received by an energy controller, and the energy controller generates a control instruction for controlling the rotation of the second rotating half-wave plate based on the energy size of the received p-polarized light; the p-polarized light passing through the second beam splitter enters the beam combiner.

[0010] As a possible implementation, the first incident unit includes a third beam splitter, a fourth beam splitter and a first focusing mirror in the transmission direction of the laser beam in sequence; wherein the laser beam output by the laser emitting unit is reflected by the third beam splitter, transmitted by the fourth beam splitter, and then irradiated to a preset area by the first focusing mirror; The measuring unit also includes an energy meter, and the laser beam transmitted through the third beam splitter is incident on the energy meter to obtain a transmission energy value, and the transmission energy value is sent to the controller; the controller is configured with the transmission-reflection ratio of the third beam splitter, and the reflection energy value of the laser beam is obtained by calculation based on the transmission-reflection ratio of the third beam splitter.

[0011] As a possible implementation method, the second incident unit includes a fifth beam splitter and a second focusing mirror in sequence in the transmission direction of the laser beam; wherein the fifth beam splitter receives the laser beam reflected by the fourth beam splitter and then reflects it to the second focusing mirror, which irradiates the laser beam to a preset area.

[0012] As a possible implementation, the measuring unit includes a variable absorption attenuator, a third focusing mirror, and a beam quality analyzer arranged in sequence on the transmission light path of the fifth beam splitter, the beam quality analyzer is used to obtain the spot size of the laser beam, and calculate the energy distribution characteristics of the laser spot based on the spot size, the transmission-reflection ratio of the first focusing mirror, and the transmission-reflection ratio of the second focusing mirror; The measuring unit also includes a camera for photographing and obtaining an image of the surface damage morphology of the photoelectric imaging detector.

[0013] As a possible implementation, the first focusing mirror is controllable to move in the z-axis direction, the second focusing mirror is controllable to move in the yz plane, and the third focusing mirror is controllable to move in the y-axis direction, so that the spot size irradiated in the preset area is the same as the spot size focused on the beam quality analyzer; The three-dimensional mobile platform moves obliquely at 45 degrees in the xy plane, so that the preset areas are intact and undamaged before the laser beam irradiates the preset areas.

[0014] As a possible implementation manner, the transmission-reflection ratio of the third beam splitter is 1:9; the transmission-reflection ratio of the fourth beam splitter is 4.7:5.3; and the transmission-reflection ratio of the fifth beam splitter is 1.1:8.9.

[0015] In a second aspect, the present invention provides a method for real-time measurement of multi-angle damage of a photoelectric imaging detector. The controller sends a second control instruction to place the detection light source in an illuminated working condition or a non-illuminated working condition, and executes the following steps to obtain the laser damage conditions under the illuminated working condition and the non-illuminated working condition respectively: S1. The controller sends a first control instruction to control the laser emitting unit to emit a laser beam according to a preset emission energy and beam type; S2. The laser beam irradiates a preset area on the photoelectric imaging detector along the first incident light path constructed by the first incident unit; S3. The laser beam irradiates a preset area on the photoelectric imaging detector along the second incident light path constructed by the second incident unit; the preset area irradiated on the photoelectric imaging detector via the first incident light path and the second incident light path is the same, and the laser beam energy is equal; S4. The reflected energy value of the laser beam is calculated by the transmission energy value obtained by the energy meter and the transmission-reflection ratio of the third beam splitter; the energy distribution characteristics of the laser spot are calculated according to the spot size obtained by the beam quality analyzer and the transmission-reflection ratio of the first focusing mirror and the transmission-reflection ratio of the second focusing mirror; the surface damage morphology image of the photoelectric imaging detector is obtained by taking a camera; the photoelectric imaging detector outputs the damage image; S5. The controller determines the damage condition based on the surface damage morphology image and the damage image of the photoelectric imaging detector, and the damage condition includes point damage, line damage or complete failure damage.

[0016] As a possible implementation method, S1 specifically includes the following steps: S10. The controller controls the laser light according to the test requirements, and controls the duration of the light by controlling the shutter, and then changes the emission energy size after the polarization attenuator and / or outputs a laser beam containing s-polarized light and / or p-polarized light according to the test requirements; S11. Adjusting the focal length of the lens group included in the beam expander and collimator and the focal length of the aspheric lens group included in the beam shaper so that the laser beam attenuated by the polarization attenuator is output as a flat-top beam; S12. According to the spot characteristics of the laser beam obtained by the beam quality analyzer, determine whether the laser beam reaches a flat-top beam distribution. If not, return to S11 for adjustment until a flat-top beam distribution is achieved.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention utilizes conventional optical elements, such as transflective mirrors, lenses, etc., to realize multi-angle simultaneous damage testing of lasers on photoelectric imaging detectors, and the optical path is simple and convenient to implement.

[0018] 2. The present invention sets a plurality of beam splitters to allow the laser beam to be incident on the photoelectric imaging detector from different angles, thereby realizing damage measurement under the joint irradiation of laser at multiple angles.

[0019] 3. The present invention realizes the simultaneous measurement of laser energy and laser spot, and can accurately measure the laser damage energy density; at the same time, it also takes into account the influence of the polarization characteristics of the incident laser, and provides an effective method for measuring the damage of the photoelectric imaging detector under the polarization state of the laser.

[0020] 4. The present invention reduces the beam divergence angle by expanding and shaping the laser beam, and changes the Gaussian beam into a flat-top beam, which can effectively avoid the problem of uneven distribution of laser energy on the photoelectric imaging detector and greatly improve the performance of laser damage testing.

[0021] 5. To avoid mutual interference between different damaged areas, the present invention uses a mobile platform to control the photoelectric imaging detector to move obliquely at 45 degrees in the plane, effectively avoiding the interference caused by damage to the vertical or horizontal transfer register of the CCD array detector.

[0022] 6. The present invention can realize the simultaneous measurement of the damage condition of the photoelectric imaging detector under the conditions of illumination and no illumination. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic diagram of the structure of a multi-angle damage real-time measurement system for a photoelectric imaging detector provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a polarization attenuator provided by an embodiment of the present invention; Figure 3 A flow chart of a method for real-time multi-angle damage measurement of a photoelectric imaging detector provided in an embodiment of the present invention.

[0024] Reference numerals 1-laser emitting unit, 10-laser, 11-shutter, 12-polarization attenuator, 1200-polarization beam splitter, 1201-beam combiner, 1202-light output reflector, 1203-first reflector, 1204-first polarizer, 1205-first rotating half-wave plate, 1206-second polarizer, 1207-first beam splitter, 1208-energy controller, 1209-second reflector, 1210-third polarizer, 1211-second rotating half-wave plate, 1212-fourth polarizer, 1213-second beam splitter, 13-beam expander collimator, 14-beam shaper; 2-first incident unit, 20-third beam splitter, 21-fourth beam splitter, 22-first focusing mirror; 3-second incident unit, 30-fifth beam splitter, 31-second focusing mirror; 4-Detection light source; 50-energy meter, 51-variable absorption attenuator, 52-third focusing mirror, 53-beam quality analyzer, 54-camera; 6-controller, 7-photoelectric imaging detector, 8-three-dimensional mobile platform. DETAILED DESCRIPTION

[0025] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, words such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and their order is not limited. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit them to be different.

[0026] It should be noted that, in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0027] In the present invention, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. The following at least one item (items) or similar expressions thereof refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (items) of a, b or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b, c can be single or multiple.

[0028] The embodiment of the present invention aims to provide a system and method for real-time measurement of multi-angle damage of a photoelectric imaging detector, which can simultaneously measure the damage of the photoelectric imaging detector under illuminated and unilluminated conditions, and can also simultaneously measure the laser damage energy and laser spot size, and obtain the image and surface damage morphology of the damaged photoelectric imaging detector in real time, so as to realize multi-angle real-time measurement of the damage of the photoelectric imaging detector. The specific implementation methods are as follows: In a first aspect, an embodiment of the present invention provides a multi-angle damage real-time measurement system for a photoelectric imaging detector, see Figure 1 , including: a laser emitting unit 1, a first incident unit 2, a second incident unit 3, a detection light source 4, a measuring unit (in Figure 1 The measuring unit is composed of an energy meter 50, a variable absorption attenuator 51, a third focusing mirror 52, a beam quality analyzer 53 and a camera 54) and a controller 6; wherein the laser emitting unit 1 is used to emit a laser beam, and the emission energy and beam type of the laser beam are adjustable.

[0029] See also Figure 1As a possible implementation, the laser emitting unit 1 includes: a laser 10, a shutter 11, a polarization attenuator 12, a beam expander collimator 13, and a beam shaper 14 in the transmission direction of the laser beam; wherein the laser 10 is used to generate a laser beam, and then the laser beam enters the shutter 11, and the shutter 11 can control the duration of the laser beam, and then the laser beam enters the polarization attenuator 12. The polarization attenuator 12 can attenuate the energy of the laser beam and can control the beam type, for example, controlling the beam type to be one of s-polarized light, p-polarized light, or a combined beam of s-polarized light and p-polarized light.

[0030] See also Figure 1 As an example, the beam expander collimator 13 is composed of two aspheric lenses, which are used to compress the spatial divergence angle of the laser beam; the beam shaper 14 is also composed of two aspheric lenses. The laser beam after being expanded and collimated by the beam expander collimator 13 enters the beam shaper 14, and the Gaussian beam is shaped into a flat-top beam.

[0031] The purpose of expanding and collimating the laser beam is to obtain a high-quality laser beam. The present application adds a polarization attenuator before expanding and collimating the laser beam, and first attenuates the laser beam generated by the laser before expanding and collimating it. This design can avoid the destruction of the beam quality of the high-quality laser beam after expansion and collimation when it is attenuated again, so the present application can obtain a high-quality beam. In addition, changing the Gaussian beam into a flat-top beam can effectively avoid the problem of uneven distribution of laser energy on the photoelectric imaging detector, greatly improving the performance of laser damage testing.

[0032] See also Figure 2 As a possible implementation, the polarization attenuator 12 includes: a polarization beam splitter 1200 , an s-polarization light path, a p-polarization light path, a beam combiner 1201 , and a light output reflector 1202 .

[0033] See also Figure 1 to Figure 2 , the laser beam passing through the shutter 11 enters the polarization beam splitter 1200 and is divided into s-polarized light and p-polarized light; the s-polarized light is attenuated once and filtered twice on the s-polarized light path and then enters the beam combiner 1201 through the first reflector 1203; the p-polarized light is attenuated once and filtered twice on the p-polarized light path and then directly enters the beam combiner 1201.

[0034] See also Figure 2As a possible implementation method, a first polarizer 1204, a first rotating half-wave plate 1205, a second polarizer 1206, a first beam splitter 1207 and a first reflector 1203 are sequentially arranged on an s-polarized light path along the transmission direction of the s-polarized light; wherein the first polarizer 1204 is consistent with the polarization direction of the s-polarized light; the rotation angle of the first rotating half-wave plate 1205 can be controllably rotated to change the intensity of the s-polarized light; the second polarizer 1206 is consistent with the polarization direction of the first polarizer 1204; the s-polarized light passing through the first beam splitter 1207 enters the beam combiner 1201 through the first reflector 1203, and the s-polarized light reflected by the first beam splitter 1207 is received by an energy controller 1208, and the energy controller 1208 generates a control instruction for controlling the rotation of the first rotating half-wave plate 1205 based on the energy of the received s-polarized light.

[0035] See also Figure 2 As a possible implementation method, a second reflector 1209, a third polarizer 1210, a second rotating half-wave plate 1211, a fourth polarizer 1212 and a second beam splitter 1213 are sequentially arranged along the transmission direction of the p-polarized light on the p-polarized light path; wherein the second reflector 1209 reflects the p-polarized light received from the polarization beam splitter 1200 to the third polarizer 1210, and the polarization direction of the third polarizer 1210 is consistent with the polarization direction of the p-polarized light; the rotation angle of the second rotating half-wave plate 1211 is controllably rotated to change the intensity of the p-polarized light; the polarization direction of the fourth polarizer 1212 is consistent with the polarization direction of the third polarizer 1210; the p-polarized light reflected by the second beam splitter 1213 is received by the energy controller 1208, and the energy controller 1208 generates a control instruction for controlling the rotation of the second rotating half-wave plate 1211 based on the energy size of the received p-polarized light; the p-polarized light passing through the second beam splitter 1213 enters the beam combiner 1201.

[0036] The measurement system provided in the embodiment of the present invention can adjust the energy intensity of the light beam by controlling the angle of the rotating half-wave plate, and the present application respectively sets two-stage polarizers on the s-polarized light path and the p-polarized light path, and performs filtering once before and after the light beam energy attenuation, which can effectively remove stray light. Compared with the prior art that only attenuates the light beam energy without filtering, the present embodiment can make the emitted light beam purer. In addition, the present application can issue corresponding control instructions based on the light beam energy size by setting a spectroscope on the light path and setting an energy controller on the reflection light path of the spectroscope, so as to make the control of the light beam energy more precise.

[0037] See also Figure 1 to Figure 2, the beam combiner 1201 combines the received s-polarized light and p-polarized light; the combined laser beam enters the light-emitting reflector 1202, and the light-emitting reflector 1202 receives the combined laser beam and reflects it to the beam expander collimator 13. Specifically, the light-emitting reflector 1202 adjusts the outgoing laser to be in the same direction as the incident laser.

[0038] The embodiment of the present invention takes into account the influence of the polarization characteristics of the incident laser and provides an effective method for measuring the damage of the photoelectric imaging detector under the polarization state of the laser.

[0039] See also Figure 1 As a possible implementation method, the laser beam is irradiated to a preset area on the photoelectric imaging detector 7 along the first incident light path constructed by the first incident unit 2; specifically, the first incident unit 2 includes a third beam splitter 20, a fourth beam splitter 21 and a first focusing mirror 22 in the transmission direction of the laser beam; wherein, the laser beam output by the laser emitting unit 1 is reflected by the third beam splitter 20 and transmitted by the fourth beam splitter 21, and then irradiated to the preset area by the first focusing mirror 22.

[0040] See also Figure 1 As a possible implementation method, the measuring unit includes an energy meter 50. The laser light beam transmitted through the third beam splitter 20 is incident on the energy meter 50 to obtain a transmission energy value, and the transmission energy value is sent to the controller 6. The controller 6 is configured with the transmission-reflection ratio of the third beam splitter 20. The reflection energy value of the laser light beam is obtained according to the transmission-reflection ratio of the third beam splitter 20. The reflection energy value can be used for subsequent calculation of the laser energy irradiated on the detector.

[0041] As an example, the transmission-reflection ratio of the third beam splitter 20 is 1:9; and the transmission-reflection ratio of the fourth beam splitter 21 is 4.7:5.3.

[0042] See also Figure 1 As a possible implementation, the laser beam irradiates the preset area on the photoelectric imaging detector along the second incident light path constructed by the second incident unit 3; specifically, the second incident unit 3 includes a fifth beam splitter 30 and a second focusing mirror 31 in the transmission direction of the laser beam; wherein the fifth beam splitter 30 receives the laser beam reflected by the fourth beam splitter 21 and then reflects it to the second focusing mirror 31, and the laser beam is irradiated to the preset area by the second focusing mirror 31. In this embodiment, the preset areas irradiated on the photoelectric imaging detector 7 via the first incident light path and the second incident light path are the same, and the laser beam energy is equal.

[0043] As an example, the transmission-reflection ratio of the fifth beam splitter 30 is 1.1:8.9.

[0044] See also Figure 1The detection light source 4 can be controllably turned on or off, so that the photoelectric imaging detector can be controllably placed in an illuminated working condition or a non-illuminated working condition.

[0045] The multi-angle damage real-time measurement system for photoelectric imaging detectors provided by the embodiment of the present invention can realize simultaneous measurement of the damage of the photoelectric imaging detectors under conditions with illumination and without illumination.

[0046] See also Figure 1 As a possible implementation, the measuring unit includes a variable absorption attenuator 51, a third focusing mirror 52 and a beam quality analyzer 53 arranged in sequence on the transmission light path of the fifth beam splitter 30. Exemplarily, the variable absorption attenuator 51 is composed of a plurality of neutral density filters of different optical densities, and is mainly used to attenuate the laser energy to ensure that the laser beam focused on the beam quality analyzer 53 by the third focusing mirror 52 is within the safe measurement range of the beam quality analyzer 53. The beam quality analyzer 53 is used to obtain the spot size of the laser beam, and calculate the energy distribution characteristics of the laser spot based on the spot size, the transmittance-reflection ratio of the first focusing mirror 22, and the transmittance-reflection ratio of the second focusing mirror 31.

[0047] The system can accurately calculate the laser energy density irradiated to the surface of the photoelectric imaging detector by integrating the spot size obtained by the comprehensive beam quality analyzer, the transmittance-reflection ratio of the first focusing mirror and the transmittance-reflection ratio of the second focusing mirror.

[0048] Specifically, the measuring unit is used to measure the damage image output by the photoelectric imaging detector 7, the energy distribution characteristics of the laser spot, and the damage morphology image on the surface of the photoelectric imaging detector; wherein the energy distribution characteristics of the laser spot are obtained by the beam quality analyzer 53; the damage morphology image on the surface of the photoelectric imaging detector is obtained by taking pictures of the camera 54 included in the measuring unit. The damage image can be output by the photoelectric imaging detector 7 itself, and in this case, it can be understood that the measuring unit and the photoelectric imaging detector 7 share the measuring device for measuring the damage image, or a measuring device configured separately for obtaining the damage image.

[0049] The embodiment of the present invention uses a camera to obtain a surface damage morphology image of a photoelectric imaging detector, and combines the damage image output by the photoelectric imaging detector itself and the surface damage morphology image of the photoelectric imaging detector to more accurately determine the damage type.

[0050] See also Figure 1As a possible implementation method, the first focusing mirror 22 is controllably movable in the z-axis direction, the second focusing mirror 31 is controllably movable in the yz plane, and the third focusing mirror 52 is controllably movable in the y-axis direction, so that the spot size irradiated on the preset area is the same as the spot size focused on the beam quality analyzer 53; and the three-dimensional mobile platform 8 moves obliquely at 45 degrees in the xy plane, so that before the laser beam irradiates the preset area, the preset area is an intact and undamaged area.

[0051] To avoid mutual interference between different damaged areas, the embodiment of the present invention uses a mobile platform to control the photoelectric imaging detector to move obliquely at 45 degrees in a plane, effectively avoiding the interference caused by damage to the vertical or horizontal transfer register of the CCD array detector.

[0052] See also Figure 1 As a possible implementation, the controller 6 receives the image output by the measuring unit, specifically, including receiving the energy distribution characteristics of the laser spot obtained by the beam quality analyzer 53, receiving the damage image output by the photoelectric imaging detector 7, and receiving the photoelectric imaging detector surface damage morphology image obtained by the camera 54. Further, the controller 6 is also used to send a first control instruction, a second control instruction, a third control instruction, and a fourth control instruction, wherein the first control instruction is used to control the laser emitting unit 1 to emit a laser beam, the second control instruction is used to control the opening or closing of the detection light source 4, the third control instruction is used to control the opening or closing of the shutter 11, and the fourth control instruction is used to control the movement of the three-dimensional mobile platform 8, and the three-dimensional mobile platform 8 is used to carry the photoelectric imaging detector 7.

[0053] See also Figure 1The working principle of the measurement system is that the controller 6 controls the detection light source 4 to be turned on or off so that the photoelectric imaging detector is in an illuminated working condition or a non-illuminated working condition. Next, the measurement system performs the following operations: according to the test requirements, a control instruction is sent to make the laser 10 emit light, and the light emission time is controlled by sending a control instruction to the shutter 11. The laser changes the energy size through the polarization attenuator 12 or outputs it as one of s-polarized light, p-polarized light, or a combined beam of s-polarized light and p-polarized light according to the test requirements. The focal length of the lens group in the beam expander collimator 13 and the focal length of the aspheric lens group in the beam shaper 14 are adjusted so that the attenuated laser is emitted as a flat-top beam. The energy meter 50 obtains the energy of the incident laser according to the transmission-reflection ratio of the third beam splitter 20. It is judged whether the flat-top beam distribution is achieved according to the laser beam spot size obtained by the beam quality analyzer 53. If not, the focal length of the lens group in the beam expander collimator 13 and the focal length of the aspheric lens group in the beam shaper 14 are continued to be adjusted until the flat-top beam distribution is achieved. The laser energy density irradiated to the surface of the photoelectric imaging detector 7 is calculated based on the transmission-reflection ratio of the first focusing mirror 22 and the second focusing mirror 31, and the laser beam spot size obtained by the beam quality analyzer 53. The camera 54 records the photoelectric imaging detector surface damage morphology image, and the controller collects the damage image output by the photoelectric imaging detector 7. Point damage, line damage, complete failure damage, etc. are determined based on the photoelectric imaging detector surface damage morphology image and the damage image.

[0054] By using the controller 6 to make the three-dimensional mobile platform 8 move obliquely at 45 degrees in the xy plane, and changing the angle of the incident light through the fifth beam splitter 30, and repeating the operations performed by the above-mentioned measurement system, the point damage, line damage, and complete failure damage of the new irradiated position of the photoelectric imaging detector 7 under the conditions of illumination and no illumination can be obtained.

[0055] The present invention utilizes conventional optical elements, such as transflectors, lenses, etc., to realize multi-angle simultaneous damage testing of laser on photoelectric imaging detectors, and the optical path implementation is simple and convenient; by setting up multiple beam splitters, the laser beam is incident on the photoelectric imaging detector from different angles, thereby realizing damage measurement under the action of multi-angle joint irradiation of laser.

[0056] In a second aspect, the present invention provides a method for real-time measurement of multi-angle damage of a photoelectric imaging detector, wherein the controller sends a second control instruction to place the detection light source in an illuminated working condition or a non-illuminated working condition, see Figure 3 , perform the following steps to obtain the laser damage conditions under illumination and without illumination respectively: S1. The controller sends a first control instruction to control the laser emitting unit to emit a laser beam according to a preset emission energy and beam type; As a possible implementation method, S1 specifically includes the following steps: S10. The controller controls the laser light according to the test requirements, and controls the duration of the light by controlling the shutter, and then changes the emission energy size after the polarization attenuator and / or outputs a laser beam containing s-polarized light and / or p-polarized light according to the test requirements; S11. Adjusting the focal length of the lens group included in the beam expander and collimator and the focal length of the aspheric lens group included in the beam shaper so that the laser beam attenuated by the polarization attenuator is output as a flat-top beam; S12. According to the spot characteristics of the laser beam obtained by the beam quality analyzer, determine whether the laser beam reaches a flat-top beam distribution. If not, return to S11 for adjustment until a flat-top beam distribution is achieved.

[0057] S2. The laser beam irradiates a preset area on the photoelectric imaging detector along the first incident light path constructed by the first incident unit; S3. The laser beam irradiates a preset area on the photoelectric imaging detector along the second incident light path constructed by the second incident unit; the preset area irradiated on the photoelectric imaging detector via the first incident light path and the second incident light path is the same, and the laser beam energy is equal; S4. The reflected energy value of the laser beam is calculated by the transmission energy value obtained by the energy meter and the transmission-reflection ratio of the third beam splitter; the energy distribution characteristics of the laser spot are calculated according to the spot size obtained by the beam quality analyzer and the transmission-reflection ratio of the first focusing mirror and the transmission-reflection ratio of the second focusing mirror; the surface damage morphology image of the photoelectric imaging detector is obtained by taking a camera; the photoelectric imaging detector outputs the damage image; S5. The controller determines the damage condition based on the surface damage morphology image and the damage image of the photoelectric imaging detector, and the damage condition includes point damage, line damage or complete failure damage.

[0058] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the illustrations of the drawings. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0059] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A photoelectric imaging detector multi-angle damage real-time measurement system, characterized in that: include: A laser emitting unit, used for emitting a laser beam, wherein the emission energy and beam type of the laser beam are adjustable; A first incident unit, wherein the laser beam irradiates a preset area on the photoelectric imaging detector along a first incident light path constructed by the first incident unit; A second incident unit, wherein the laser beam irradiates a preset area on the photoelectric imaging detector along a second incident light path constructed by the second incident unit; The preset areas irradiated on the photoelectric imaging detector by the first incident light path and the second incident light path are the same, and the energy of the laser beams is equal; The detection light source can be controlled to be turned on or off, so that the photoelectric imaging detector can be controlled to be in a light-on condition or a no-light condition; A measuring unit, used to measure the damage image output by the photoelectric imaging detector, the energy distribution characteristics of the laser spot, and the damage morphology image on the surface of the photoelectric imaging detector; And a controller receives the image output by the measuring unit, and sends a first control instruction, a second control instruction, a third control instruction and a fourth control instruction, wherein the first control instruction is used to control the laser emitting unit to emit a laser beam, the second control instruction is used to control the opening or closing of the detection light source, the third control instruction is used to control the opening or closing of the shutter, and the fourth control instruction is used to control the movement of a three-dimensional mobile platform, and the three-dimensional mobile platform is used to carry a photoelectric imaging detector.

2. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 1 is characterized in that: The laser emitting unit includes, in sequence, in the transmission direction of the laser beam: A laser for generating a laser beam; Shutter, used to control the duration of the laser beam; A polarization attenuator, used for attenuating the energy of a laser beam and controlling the beam type, wherein the beam type is one of s-polarized light, p-polarized light, or a combined beam of s-polarized light and p-polarized light; Beam expander collimator, used to compress the spatial divergence angle of the laser beam; and a beam shaper for shaping the expanded and collimated laser beam to obtain a flat-top beam.

3. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 2 is characterized in that: The polarization attenuator comprises: A polarization beam splitter, wherein the laser beam passing through the shutter enters the polarization beam splitter and is divided into s-polarized light and p-polarized light; An s-polarized light path, wherein the s-polarized light enters the beam combiner through the first reflector after being attenuated once and filtered twice on the s-polarized light path; A p-polarized light path, where the p-polarized light directly enters the beam combiner after being attenuated once and filtered twice on the p-polarized light path; A beam combiner combines the received s-polarized light and p-polarized light; The light-emitting reflector receives the combined laser beam and reflects it to the beam expander collimator.

4. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 3 is characterized in that: A first polarizer, a first rotating half-wave plate, a second polarizer, a first beam splitter and a first reflector are sequentially arranged on the s-polarized light path along the transmission direction of the s-polarized light; wherein the first polarizer is consistent with the polarization direction of the s-polarized light; the rotation angle of the first rotating half-wave plate can be controlled to change the intensity of the s-polarized light; the polarization direction of the second polarizer is consistent with that of the first polarizer; the s-polarized light passing through the first beam splitter enters the beam combiner through the first reflector, and the s-polarized light reflected by the first beam splitter is received by the energy controller, and the energy controller generates a control instruction for controlling the rotation of the first rotating half-wave plate based on the energy of the received s-polarized light; A second reflector, a third polarizer, a second rotating half-wave plate, a fourth polarizer and a second beam splitter are sequentially arranged on the p-polarized light path along the transmission direction of the p-polarized light; wherein the second reflector reflects the p-polarized light received from the polarization beam splitter to the third polarizer, and the polarization direction of the third polarizer is consistent with the polarization direction of the p-polarized light; the rotation angle of the second rotating half-wave plate is controllably rotated to change the intensity of the p-polarized light; the polarization direction of the fourth polarizer is consistent with the polarization direction of the third polarizer; the p-polarized light reflected by the second beam splitter is received by an energy controller, and the energy controller generates a control instruction for controlling the rotation of the second rotating half-wave plate based on the energy size of the received p-polarized light; the p-polarized light passing through the second beam splitter enters the beam combiner.

5. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 1 is characterized in that: The first incident unit includes a third beam splitter, a fourth beam splitter and a first focusing mirror in the transmission direction of the laser beam. The laser beam output by the laser emitting unit is reflected by the third beam splitter, transmitted by the fourth beam splitter, and then irradiated to a preset area by the first focusing mirror. The measuring unit also includes an energy meter, and the laser beam transmitted through the third beam splitter is incident on the energy meter to obtain a transmission energy value, and the transmission energy value is sent to a controller; the controller is configured with the transmission-reflection ratio of the third beam splitter, and the reflection energy value of the laser beam is obtained by calculation based on the transmission-reflection ratio of the third beam splitter.

6. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 5 is characterized in that: The second incident unit includes a fifth beam splitter and a second focusing mirror in sequence in the transmission direction of the laser beam; wherein the fifth beam splitter receives the laser beam reflected by the fourth beam splitter and then reflects it to the second focusing mirror, and the second focusing mirror irradiates the laser beam to the preset area.

7. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 6 is characterized in that: The measuring unit includes a variable absorption attenuator, a third focusing mirror and a beam quality analyzer arranged in sequence on the transmission light path of the fifth beam splitter, wherein the beam quality analyzer is used to obtain the spot size of the laser beam, and calculate the energy distribution characteristics of the laser spot based on the spot size, the transmission-reflection ratio of the first focusing mirror and the transmission-reflection ratio of the second focusing mirror; The measuring unit also includes a camera for photographing and obtaining an image of the surface damage morphology of the photoelectric imaging detector.

8. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 7 is characterized in that: The first focusing mirror is controllable to move in the z-axis direction, the second focusing mirror is controllable to move in the yz plane, and the third focusing mirror is controllable to move in the y-axis direction, so that the spot size irradiated in the preset area is the same as the spot size focused on the beam quality analyzer; The three-dimensional moving platform moves obliquely at 45 degrees in the xy plane, so that the preset areas are intact and undamaged before the laser beam irradiates the preset areas.

9. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 6 is characterized in that: The transmission-reflection ratio of the third beam splitter is 1:9; the transmission-reflection ratio of the fourth beam splitter is 4.7:5.3; and the transmission-reflection ratio of the fifth beam splitter is 1.1:8.

9.

10. A real-time measurement method for multi-angle damage of a photoelectric imaging detector, characterized in that: The controller sends a second control instruction to place the detection light source in an illuminated working condition or a non-illuminated working condition, and executes the following steps to obtain the laser damage conditions under the illuminated working condition and the non-illuminated working condition respectively: S1. The controller sends a first control instruction to control the laser emitting unit to emit a laser beam according to a preset emission energy and beam type; S2. The laser beam irradiates a preset area on the photoelectric imaging detector along the first incident light path constructed by the first incident unit; S3. The laser beam irradiates a preset area on the photoelectric imaging detector along the second incident light path constructed by the second incident unit; the preset area irradiated on the photoelectric imaging detector via the first incident light path and the second incident light path is the same, and the laser beam energy is equal; S4. The reflected energy value of the laser beam is calculated by the transmission energy value obtained by the energy meter and the transmission-reflection ratio of the third beam splitter; the energy distribution characteristics of the laser spot are calculated according to the spot size obtained by the beam quality analyzer and the transmission-reflection ratio of the first focusing mirror and the transmission-reflection ratio of the second focusing mirror; the surface damage morphology image of the photoelectric imaging detector is obtained by taking a camera; the photoelectric imaging detector outputs the damage image; S5. The controller determines the damage condition based on the surface damage morphology image and the damage image of the photoelectric imaging detector, wherein the damage condition includes point damage, line damage or complete failure damage.

11. The real-time multi-angle damage measurement method of the photoelectric imaging detector according to claim 10 is characterized in that: The S1 specifically includes the following steps: S10. The controller controls the laser light according to the test requirements, and controls the duration of the light by controlling the shutter, and then changes the emission energy size after the polarization attenuator and / or outputs a laser beam containing s-polarized light and / or p-polarized light according to the test requirements; S11. Adjusting the focal length of the lens group included in the beam expander and collimator and the focal length of the aspheric lens group included in the beam shaper so that the laser beam attenuated by the polarization attenuator is output as a flat-top beam; S12. According to the spot characteristics of the laser beam obtained by the beam quality analyzer, determine whether the laser beam reaches a flat-top beam distribution. If not, return to S11 for adjustment until a flat-top beam distribution is achieved.

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