A real-time measurement system and method for multi-angle damage of an optoelectronic imaging detector

Abstract

The present invention belongs to the technical field of laser damage measurement, and relates to a real-time multi-angle damage measurement system and method for an optoelectronic imaging detector. The measurement system includes: a laser emission unit, a first incident unit, a second incident unit, a detection light source, a measurement unit, and a controller. The laser emission unit is used to emit a laser beam with adjustable energy and type. The laser beam irradiates the same preset area on the optoelectronic imaging detector along the optical path constructed by the first incident unit and along the optical path constructed by the second incident unit, and the energy of the laser beam is equal. The detection light source enables the optoelectronic imaging detector to be controllably in a light-illuminated working condition or a non-light-illuminated working condition. The measurement unit is used to measure the damage image output by the optoelectronic imaging detector, the energy distribution characteristics of the laser spot, and the surface damage morphology image of the optoelectronic imaging detector. The controller receives the images output by the measurement unit and can issue four control commands. The present invention can achieve damage measurement under the action of multi-angle co-irradiation of the laser.

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] To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a real-time multi-angle damage measurement system for an optoelectronic imaging detector, comprising:

[0008] A laser emission unit for emitting a laser beam, the emission energy and beam type of the laser beam being adjustable;

[0009] A first incident unit, the laser beam irradiating a preset area on the optoelectronic imaging detector along a first incident optical path constructed by the first incident unit;

[0010] A second incident unit, the laser beam irradiating a preset area on the optoelectronic imaging detector along a second incident optical path constructed by the second incident unit; the preset areas irradiated on the optoelectronic imaging detector along the first incident optical path and the second incident optical path are the same, and the energies of the laser beams are equal;

[0011] A detection light source that can be controllably turned on or off, so that the optoelectronic imaging detector can be controllably in a light-illuminated working condition or a non-light-illuminated working condition;

[0012] A measurement unit for measuring the damage image output by the optoelectronic imaging detector, the energy distribution characteristics of the laser spot, and the surface damage morphology image of the optoelectronic imaging detector;

[0013] And a controller that receives the images output by the measurement unit and sends a first control instruction, a second control instruction, a third control instruction, and a fourth control instruction. The first control instruction is used to control the laser emission unit to emit a laser beam, the second control instruction is used to control the turning on or off of the detection light source, the third control instruction is used to control the turning on or off of the shutter, and the fourth control instruction is used to control the movement of a three-dimensional moving platform, and the three-dimensional moving platform is used to carry the optoelectronic imaging detector.

[0014] As a possible implementation, the laser emission unit sequentially includes in the transmission direction of the laser beam:

[0015] A laser for generating a laser beam;

[0016] A shutter for controlling the light-emitting duration of the laser beam;

[0017] A polarization attenuator for attenuating the energy of the laser beam and controlling the beam type, and the beam type is one of s-polarized light, p-polarized light, or a combined beam of s-polarized light and p-polarized light;

[0018] A beam expander-collimator for compressing the spatial divergence angle of the laser beam;

[0019] And a beam shaper for shaping the expanded and collimated laser beam to obtain a flat-top beam.

[0020] As a possible implementation, the polarization attenuator includes:

[0021] A polarization beam splitter. After the laser beam passing through the shutter enters the polarization beam splitter, it is divided into an s-polarized light and a p-polarized light.

[0022] An s-polarized light path. The s-polarized light is attenuated once and filtered twice on the s-polarized light path, and then enters the beam combiner through the first mirror.

[0023] A p-polarized light path. The p-polarized light is attenuated once and filtered twice on the p-polarized light path, and then directly enters the beam combiner.

[0024] A beam combiner that combines the received s-polarized light and p-polarized light.

[0025] An output light mirror that receives the combined laser beam and reflects it to the beam expander and collimator.

[0026] As a possible implementation, on the s-polarized light path, a first polarizer, a first rotating half-wave plate, a second polarizer, a first beam splitter, and a first mirror are sequentially arranged along the transmission direction of the s-polarized light. Among them, the polarization direction of the first polarizer is consistent with that of the s-polarized light; the rotation angle of the first rotating half-wave plate is 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 mirror, and the s-polarized light reflected by the first beam splitter is received by the energy controller. The energy controller generates a control instruction for controlling the rotation of the first rotating half-wave plate based on the energy magnitude of the received s-polarized light.

[0027] On the p-polarized light path, a second mirror, a third polarizer, a second rotating half-wave plate, a fourth polarizer, and a second beam splitter are sequentially arranged along the transmission direction of the p-polarized light. Among them, the second mirror 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 that 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 that of the third polarizer; the p-polarized light reflected by the second beam splitter is received by the energy controller. The energy controller generates a control instruction for controlling the rotation of the second rotating half-wave plate based on the energy magnitude of the received p-polarized light; the p-polarized light passing through the second beam splitter enters the beam combiner.

[0028] As a possible implementation, the first incident unit sequentially includes a third beam splitter, a fourth beam splitter, and a first focusing mirror in the transmission direction of the laser beam. Among them, the laser beam output by the laser emission unit is reflected by the third beam splitter and transmitted by the fourth beam splitter, and then irradiated to the preset area by the first focusing mirror.

[0029] The measuring unit further includes an energy meter. The laser beam transmitted through the third beam splitter is incident on the energy meter to obtain a transmitted energy value, and the transmitted energy value is sent to the controller. The controller is configured with the transmission and reflection ratio of the third beam splitter, and the reflected energy value of the laser beam is calculated based on the transmission and reflection ratio of the third beam splitter.

[0030] As a possible implementation, the second incident unit sequentially includes a fifth beam splitter and a second focusing mirror in the transmission direction of the laser beam. Among them, the fifth beam splitter reflects the laser beam reflected by the fourth beam splitter to the second focusing mirror, and the second focusing mirror irradiates a preset area.

[0031] 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 optical path of the fifth beam splitter. The beam quality analyzer is used to obtain the spot size of the laser beam, and calculate the laser spot energy distribution characteristics based on the spot size, the transmission and reflection ratio of the first focusing mirror, and the transmission and reflection ratio of the second focusing mirror.

[0032] The measuring unit further includes a camera for taking an image of the surface damage morphology of the photoelectric imaging detector.

[0033] As a possible implementation, the first focusing mirror can be controlled to move in the z-axis direction, the second focusing mirror can be controlled to move in the yz plane, and the third focusing mirror can be controlled to move 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.

[0034] The three-dimensional moving platform moves obliquely at a 45-degree angle in the xy plane, so that the preset area is intact and undamaged before the laser beam irradiates the preset area.

[0035] As a possible implementation, the transmission and reflection ratio of the third beam splitter is 1:9; the transmission and reflection ratio of the fourth beam splitter is 4.7:5.3; the transmission and reflection ratio of the fifth beam splitter is 1.1:8.9.

[0036] In a second aspect, the present invention provides a method for real-time multi-angle damage measurement of a photoelectric imaging detector. The controller sends a second control instruction to make the detection light source in a light-on working condition or a light-off working condition, and the following steps are executed to obtain the laser damage conditions under the light-on working condition and the light-off working condition respectively:

[0037] 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.

[0038] S2. The laser beam irradiates a preset area on the photoelectric imaging detector along the first incident optical path constructed by the first incident unit.

[0039] S3. The laser beam irradiates on a preset area of the photoelectric imaging detector along the second incident optical path constructed by the second incident unit; the preset areas irradiated on the photoelectric imaging detector through the first incident optical path and the second incident optical path are the same, and the energies of the laser beams are equal;

[0040] S4. The reflected energy value of the laser beam is calculated from the transmitted energy value obtained by the energy meter and the transmission - reflection ratio of the third beam splitter; the laser spot energy distribution characteristics are calculated based on the spot size obtained by the beam quality analyzer and the transmission - reflection ratios of the first focusing mirror and the second focusing mirror; the surface damage morphology image of the photoelectric imaging detector is obtained by camera shooting; the photoelectric imaging detector outputs a damage image;

[0041] S5. The controller determines the damage situation based on the surface damage morphology image and the damage image of the photoelectric imaging detector, and the damage situation includes point damage, line damage or complete failure damage.

[0042] As a possible implementation, S1 specifically includes the following steps:

[0043] S10. The controller controls the laser to emit light according to the test requirements, controls the light - emitting duration by controlling the shutter, and then changes the emission energy size after passing through the polarization attenuator and / or outputs a laser beam containing s - polarized light and / or p - polarized light according to the test requirements;

[0044] S11. Adjust the focal lengths of the lens group included in the beam expander - collimator and the aspherical lens group included in the beam shaper so that the laser beam attenuated by the polarization attenuator outputs as a flat - top beam;

[0045] S12. According to the spot characteristics of the laser beam obtained by the beam quality analyzer, determine whether the laser beam reaches the flat - top beam distribution. If not, return to S11 for adjustment until the flat - top beam distribution is achieved.

[0046] Compared with the prior art, the beneficial effects produced by the present invention are as follows:

[0047] 1. The present invention can realize the multi - angle simultaneous damage test of the laser on the photoelectric imaging detector by using conventional optical elements such as beam splitters and lenses, and the implementation of the optical path is simple and convenient.

[0048] 2. The present invention realizes the damage measurement under the co - irradiation of the laser at multiple angles by arranging multiple beam splitters to make the laser beam incident on the photoelectric imaging detector from different angles.

[0049] 3. The present invention realizes the simultaneous measurement of the laser energy and the laser spot, and can accurately measure the laser damage energy density; at the same time, it also considers the influence of the polarization characteristics of the incident laser, providing an effective method for the damage measurement of the photoelectric imaging detector in the polarization state of the laser.

[0050] 4. The present invention reduces the beam divergence angle by beam expansion and shaping of 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.

[0051] 5. To avoid the mutual interference of different damage areas, the present invention uses a moving platform to control the photoelectric imaging detector to move obliquely at an angle of 45 degrees in the plane, effectively avoiding the interference effects caused by damage to the vertical or horizontal transfer registers of the CCD area array detector.

[0052] 6. The present invention can simultaneously measure the damage conditions of the photoelectric imaging detector under illuminated and non-illuminated conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic 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:

[0054] Figure 1 is a schematic structural diagram of a multi-angle damage real-time measurement system for a photoelectric imaging detector provided by an embodiment of the present invention;

[0055] Figure 2 is a schematic structural diagram of a polarization attenuator provided by an embodiment of the present invention;

[0056] Figure 3 is a flowchart of a multi-angle damage real-time measurement method for a photoelectric imaging detector provided by an embodiment of the present invention.

[0057] REFERENCE NUMERALS

[0058] 1 - Laser emission unit, 10 - Laser, 11 - Shutter, 12 - Polarization attenuator, 1200 - Polarizing beam splitter, 1201 - Beam combiner, 1202 - Output mirror, 1203 - First mirror, 1204 - First polarizer, 1205 - First rotating half-wave plate, 1206 - Second polarizer, 1207 - First beam splitter, 1208 - Energy controller, 1209 - Second mirror, 1210 - Third polarizer, 1211 - Second rotating half-wave plate, 1212 - Fourth polarizer, 1213 - Second beam splitter, 13 - Beam expander-collimator, 14 - Beam shaper;

[0059] 2 - First incident unit, 20 - Third beam splitter, 21 - Fourth beam splitter, 22 - First focusing mirror;

[0060] 3 - Second incident unit, 30 - Fifth beam splitter, 31 - Second focusing mirror;

[0061] 4-Detection light source;

[0062] 50-energy meter, 51-variable absorption attenuator, 52-third focusing mirror, 53-beam quality analyzer, 54-camera;

[0063] 6-controller, 7-photoelectric imaging detector, 8-three-dimensional mobile platform. DETAILED DESCRIPTION

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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:

[0068] In a first aspect, an embodiment of the present invention provides a real-time multi-angle damage measurement system for an optoelectronic imaging detector. Refer to Figure 1 , which includes: a laser emission unit 1, a first incident unit 2, a second incident unit 3, a detection light source 4, a measurement unit (in Figure 1 , the measurement 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 emission unit 1 is used to emit a laser beam, and the emission energy and beam type of the laser beam are adjustable.

[0069] Refer to Figure 1 , as a possible implementation manner, the laser emission unit 1 sequentially includes, in the transmission direction of the laser beam: a laser 10, a shutter 11, a polarization attenuator 12, a beam expander-collimator 13, and a beam shaper 14; wherein, the laser 10 is used to generate a laser beam, and then the laser beam enters the shutter 11. The shutter 11 can control the light output 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, control 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.

[0070] Refer to Figure 1 , as an example, the beam expander-collimator 13 is composed of two aspherical lenses and is used to compress the spatial divergence angle of the laser beam; the beam shaper 14 is also composed of two aspherical lenses. The laser beam expanded and collimated by the beam expander-collimator 13 enters the beam shaper 14 to shape the Gaussian beam into a flat-top beam.

[0071] The purpose of expanding and collimating the laser beam is to obtain a high-quality laser beam. In this application, a polarization attenuator is added before expanding and collimating the laser beam, and the laser beam generated by the laser is first attenuated and then expanded and collimated. With such a design, it can be avoided that the high-quality laser beam after expansion and collimation is damaged in beam quality when attenuated again, so this 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 optoelectronic imaging detector, greatly improving the performance of laser damage testing.

[0072] Refer to Figure 2 , as a possible implementation manner, the polarization attenuator 12 includes: a polarization beam splitter 1200, an s-polarization optical path, a p-polarization optical path, a beam combiner 1201, and an output light reflecting mirror 1202.

[0073] Refer to Figures 1 to 2The laser beam passing through the shutter 11 is divided into s-polarized light and p-polarized light after entering the polarization beam splitter 1200; the s-polarized light undergoes one attenuation and two filtrations on the s-polarized light path and then enters the beam combiner 1201 through the first mirror 1203; the p-polarized light directly enters the beam combiner 1201 after undergoing one attenuation and two filtrations on the p-polarized light path.

[0074] See Figure 2 As a possible implementation, a first polarizer 1204, a first rotating half-wave plate 1205, a second polarizer 1206, a first beam splitter 1207, and a first mirror 1203 are sequentially arranged along the transmission direction of the s-polarized light on the s-polarized light path; among them, the polarization direction of the first polarizer 1204 is consistent with that of the s-polarized light; the rotation angle of the first rotating half-wave plate 1205 is controllably rotated to change the intensity of the s-polarized light; the polarization direction of the second polarizer 1206 is consistent with that of the first polarizer 1204; the s-polarized light passing through the first beam splitter 1207 enters the beam combiner 1201 through the first mirror 1203, and the s-polarized light reflected by the first beam splitter 1207 is received by the 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 magnitude of the received s-polarized light.

[0075] See Figure 2 As a possible implementation, a second mirror 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; among them, the second mirror 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 that 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 that 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 magnitude of the received p-polarized light; the p-polarized light passing through the second beam splitter 1213 enters the beam combiner 1201.

[0076] The measurement system provided by the embodiments of the present invention can adjust the beam energy intensity by controlling the angle of the rotating half-wave plate. In addition, two stages of polarizers are respectively arranged on the s-polarization optical path and the p-polarization optical path in this application, and filtering is performed once before and after the beam energy attenuation, which can effectively remove stray light. Compared with the prior art where only the beam energy is attenuated without filtering, the beam emitted in this embodiment is purer. Furthermore, by arranging a beam splitter on the optical path and an energy controller on the reflected optical path of the beam splitter in this application, corresponding control instructions can be issued based on the beam energy magnitude, making the control of the beam energy more accurate.

[0077] See Figures 1 to 2 , the beam combiner 1201 combines the received s-polarized light and p-polarized light; the combined laser beam enters the output mirror 1202, and the output mirror 1202 receives the combined laser beam and reflects it to the beam expander and collimator 13. Specifically, the output mirror 1202 adjusts the output laser to have the same direction as the incident laser.

[0078] The embodiments of the present invention consider the influence of the polarization characteristics of the incident laser, and provide an effective method for measuring the damage of the photoelectric imaging detector under the polarization state of the laser.

[0079] See Figure 1 , as a possible implementation manner, the laser beam irradiates a preset area on the photoelectric imaging detector 7 along the first incident optical path constructed by the first incident unit 2; specifically, the first incident unit 2 sequentially 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; among them, the laser beam output by the laser emission 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.

[0080] See Figure 1 , as a possible implementation manner, the measurement unit includes an energy meter 50, and the laser beam transmitted by the third beam splitter 20 is incident on the energy meter 50 to obtain the transmitted energy value, and the transmitted energy value is sent to the controller 6; the transmittance ratio of the third beam splitter 20 is configured in the controller 6, and the reflected energy value of the laser beam is calculated according to the transmittance ratio of the third beam splitter 20, and this reflected energy value can be used for subsequent calculation of the laser energy irradiated on the detector.

[0081] As an example, the transmittance ratio of the third beam splitter 20 is 1:9; the transmittance ratio of the fourth beam splitter 21 is 4.7:5.3.

[0082] See Figure 1, as a possible implementation, the laser beam irradiates on a preset area of the photoelectric imaging detector along the second incident optical path constructed by the second incident unit 3; specifically, the second incident unit 3 sequentially 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 reflects the laser beam reflected by the fourth beam splitter 21 to the second focusing mirror 31, and the second focusing mirror 31 irradiates it to the preset area. In this embodiment, the preset areas irradiated on the photoelectric imaging detector 7 through the first incident optical path and the second incident optical path are the same, and the energies of the laser beams are equal.

[0083] As an example, the transmittance-to-reflectance ratio of the fifth beam splitter 30 is 1.1:8.9.

[0084] See Figure 1 , the detection light source 4 can be controllably turned on or off so that the photoelectric imaging detector can be controllably in a light-illuminated working condition or a non-light-illuminated working condition.

[0085] By using the multi-angle damage real-time measurement system for the photoelectric imaging detector provided by the embodiment of the present invention, it is possible to simultaneously measure the damage conditions of the photoelectric imaging detector under light-illuminated and non-light-illuminated working conditions.

[0086] See Figure 1 , as a possible implementation, the measurement unit sequentially includes a variable absorption attenuator 51, a third focusing mirror 52, and a beam quality analyzer 53 arranged on the transmission optical path of the fifth beam splitter 30. Exemplarily, the variable absorption attenuator 51 is composed of multiple neutral density filter sheets with different optical density sizes, and is mainly used for attenuating 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 and obtain the laser spot energy distribution characteristics based on the spot size, the transmittance-to-reflectance ratio of the first focusing mirror 22, and the transmittance-to-reflectance ratio of the second focusing mirror 31.

[0087] By comprehensively using the spot size obtained by the beam quality analyzer, the transmittance-to-reflectance ratio of the first focusing mirror, and the transmittance-to-reflectance ratio of the second focusing mirror, this system can accurately calculate the laser energy density irradiated on the surface of the photoelectric imaging detector.

[0088] Specifically, the measurement unit is used to measure the damage image output by the optoelectronic imaging detector 7, the energy distribution characteristics of the laser spot, and the surface damage morphology image of the optoelectronic imaging detector. Among them, the energy distribution characteristics of the laser spot are obtained by the beam quality analyzer 53, and the surface damage morphology image of the optoelectronic imaging detector is obtained by the camera 54 included in the measurement unit. The damage image can be output by the optoelectronic imaging detector 7 itself. At this time, it can be understood that the measurement unit and the optoelectronic imaging detector 7 share the measurement device for measuring the damage image. It can also be that a measurement device dedicated to obtaining the damage image is configured separately.

[0089] In the embodiment of the present invention, a camera is used to obtain the surface damage morphology image of the optoelectronic imaging detector. By combining the damage image output by the optoelectronic imaging detector itself and the surface damage morphology image of the optoelectronic imaging detector, the damage type can be determined more accurately.

[0090] See Figure 1 , as a possible implementation, the first focusing mirror 22 is controllably moved in the z-axis direction, the second focusing mirror 31 is controllably moved in the yz plane, and the third focusing mirror 52 is controllably moved 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 moving platform 8 moves obliquely at an angle of 45 degrees in the xy plane so that the preset area is intact and undamaged before the laser beam irradiates the preset area.

[0091] To avoid the mutual interference of different damage areas, in the embodiment of the present invention, the moving platform is used to control the optoelectronic imaging detector to move obliquely at an angle of 45 degrees in the plane, effectively avoiding the interference effect caused by the damage of the vertical or horizontal transfer register of the CCD area array detector.

[0092] See Figure 1 , as a possible implementation, the controller 6 receives the images output by the measurement unit. Specifically, it includes receiving the energy distribution characteristics of the laser spot obtained by the beam quality analyzer 53, receiving the damage image output by the optoelectronic imaging detector 7, and receiving the surface damage morphology image of the optoelectronic imaging detector obtained by the camera 54. Further, the controller 6 is also used to send the first control instruction, the second control instruction, the third control instruction, and the fourth control instruction. Among them, 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 moving platform 8. The three-dimensional moving platform 8 is used to carry the optoelectronic imaging detector 7.

[0093] See Figure 1, the working principle of this measurement system is that the controller 6 controls the opening or closing of the detection light source 4 to make the photoelectric imaging detector in the light-illuminated condition or the non-light-illuminated condition. Next, the measurement system performs the following operations: send a control instruction according to the test requirements to make the laser 10 emit light, and control the light-emitting duration by sending a control instruction to the shutter 11. The laser changes its energy size through the polarization attenuator 12 or outputs one of s-polarized light, p-polarized light, or the combined light of s-polarized light and p-polarized light according to the test requirements. Adjust the focal length of the lens group in the beam expander and collimator 13 and the focal length of the aspherical lens group in the beam shaper 14 to make the attenuated laser emit as a flat-top beam. The energy meter 50 obtains the energy of the incident laser according to the transmission and reflection ratio of the third beam splitter 20. Judge whether the flat-top beam distribution is achieved according to the laser beam spot size obtained by the beam quality analyzer 53. If not, continue to adjust the focal length of the lens group in the beam expander and collimator 13 and the focal length of the aspherical lens group in the beam shaper 14 until the flat-top beam distribution is achieved. Calculate the laser energy density irradiated on the surface of the photoelectric imaging detector 7 according to the transmission and 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 takes pictures to record the damage morphology image on the surface of the photoelectric imaging detector. The controller collects the damage image output by the photoelectric imaging detector 7, and judges the point damage, line damage, complete failure damage, etc. according to the damage morphology image and the damage image on the surface of the photoelectric imaging detector.

[0094] The controller 6 makes the three-dimensional moving platform 8 move obliquely at a 45-degree angle in the xy plane, and changes the angle of the incident light through the fifth beam splitter 30. By repeating the operations performed by the above measurement system, the point damage, line damage, and complete failure damage conditions of the new irradiation position of the photoelectric imaging detector 7 under the light-illuminated condition and the non-light-illuminated condition can be obtained.

[0095] The present invention can realize the multi-angle simultaneous damage test of the laser on the photoelectric imaging detector by using conventional optical elements such as beam splitters and lenses. The optical path implementation is simple and convenient. By setting multiple beam splitters, the laser beam is incident on the photoelectric imaging detector from different angles, realizing the damage measurement under the multi-angle common irradiation of the laser.

[0096] 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 make the detection light source in the light-illuminated condition or the non-light-illuminated condition. Refer to Figure 3 , and perform the following steps to obtain the laser damage conditions under the light-illuminated condition and the non-light-illuminated condition respectively:

[0097] S1. The controller sends a first control instruction to control the laser emission unit to emit a laser beam according to the preset emission energy and beam type;

[0098] As a possible implementation, S1 specifically includes the following steps:

[0099] S10. The controller controls the laser to emit light according to the test requirements, controls the light emission duration through the shutter, and then changes the emission energy size after passing through the polarization attenuator and / or outputs a laser beam containing s-polarized light and / or p-polarized light according to the test requirements;

[0100] S11. Adjust the focal length of the lens group included in the beam expander-collimator and the focal length of the aspherical lens group included in the beam shaper so that the laser beam attenuated by the polarization attenuator is output as a flat-top beam;

[0101] S12. According to the spot characteristics of the laser beam obtained by the beam quality analyzer, determine whether the laser beam reaches the flat-top beam distribution. If not, return to S11 for adjustment until the flat-top beam distribution is achieved.

[0102] S2. The laser beam irradiates on a preset area of the photoelectric imaging detector along the first incident optical path constructed by the first incident unit;

[0103] S3. The laser beam irradiates on a preset area of the photoelectric imaging detector along the second incident optical path constructed by the second incident unit; the preset areas irradiated on the photoelectric imaging detector along the first incident optical path and the second incident optical path are the same, and the laser beam energies are equal;

[0104] S4. Calculate the reflected energy value of the laser beam from the transmitted energy value obtained by the energy meter and the transmission-reflection ratio of the third beam splitter; calculate the laser spot energy distribution characteristics from the spot size obtained by the beam quality analyzer and the transmission-reflection ratios of the first focusing mirror and the second focusing mirror; obtain the surface damage morphology image of the photoelectric imaging detector by camera shooting; the photoelectric imaging detector outputs the damage image;

[0105] S5. The controller determines the damage situation based on the surface damage morphology image and the damage image of the photoelectric imaging detector. The damage situation includes point damage, line damage, or complete failure damage.

[0106] Although the present invention has been described in conjunction with various embodiments herein, however, in the process of implementing the claimed invention, those skilled in the art can understand and realize other variations of the disclosed embodiments by viewing the drawings, the disclosure content, and the accompanying drawings description. In the specification, the term "comprising" does not exclude other components or steps, and "a" or "one" does not exclude a plurality. A single processor or other unit can implement several functions listed in the specification. Certain measures are recited in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0107] Although the present invention has been described in connection with specific features and their embodiments, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the invention. Accordingly, the present specification and the drawings are merely illustrative of the invention and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A photoelectric imaging detector multi-angle damage real-time measurement system, characterized in that: include: A laser emitting unit, used to emit a laser beam, wherein the emission energy and beam type of the laser beam are adjustable; the laser emitting unit includes a laser in the transmission direction of the laser beam, used to generate the laser beam; and a shutter, used to control the duration of the laser beam; A polarization attenuator is 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; a beam expander collimator is used for compressing the spatial divergence angle of the laser beam; a beam shaper is used for shaping the laser beam after beam expansion and collimation to obtain a flat-top beam; the polarization attenuator includes 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 a 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; The beam combiner combines the received s-polarized light and p-polarized light; the light output reflector receives the combined laser beam and reflects it to the beam expander collimator; 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: 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.

3. 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.

4. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 3 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.

5. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 4 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.

6. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 5 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.

7. The photoelectric imaging detector multi-angle damage real-time measurement system according to claim 4 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.

8. A real-time measurement method for multi-angle damage of a photoelectric imaging detector, characterized in that: The method for real-time measurement of multi-angle damage of a photoelectric imaging detector uses the real-time measurement system for multi-angle damage of a photoelectric imaging detector according to any one of claims 1 to 7; the controller sends a second control instruction to make the detection light source be 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.

9. The real-time multi-angle damage measurement method of the photoelectric imaging detector according to claim 8 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.

Images