Optical imaging system with continuous protection against pulsed laser-induced blindness

Abstract

This invention relates to the field of optical imaging system technology, and more particularly to an optical imaging system for continuous protection against pulsed laser-induced blindness. The system includes a secondary imaging optical system, an imaging detector, a nonlinear absorption-type optical limiter, and a two-dimensional moving unit. The secondary imaging optical system comprises a primary imaging optical component and a secondary imaging optical component. After the light beam enters the secondary imaging optical system, it is focused by the primary imaging optical component to form a primary image focal point, and then imaged onto the imaging detector by the secondary imaging optical component. The nonlinear absorption-type optical limiter is mounted on the two-dimensional moving unit and positioned near the primary image plane of the secondary imaging optical system's principal optical axis. The two-dimensional moving unit drives the movement of the nonlinear absorption-type optical limiter, allowing the incident light beam to pass through different positions on the nonlinear absorption-type optical limiter. The advantage is that it provides continuous laser protection for the imaging detector, achieving automatic protection for the optical imaging system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical imaging systems, and particularly relates to an optical imaging system capable of resisting continuous laser damage and blinding. BACKGROUND

[0002] With the development and wide application of laser technology, laser has posed a growing threat to the working safety of optical imaging systems, such as photoelectric countermeasure equipment, laser ranging equipment, laser autonomous navigation equipment, etc. In a conventional optical system, a parallel light beam is converged on an imaging spot on the surface of an imaging detector (the typical spot size is about 1 to 2 pixels, and for a certain type of CMOS imaging detector, the pixel size is 2.4 µm x 2.4 µm, and the spot size corresponding to 2 pixels is about 23 µm 2 ), resulting in a very high power / energy density of the laser beam on the surface of the imaging detector. In particular, pulsed laser (common pulse width is in the order of milliseconds to nanoseconds) is more likely to cause damage and blinding of the imaging detector in the optical imaging system under the action of pulsed laser, and thus causes the failure of the optical imaging system. From the perspective of photoelectric countermeasure attack and defense and laser protection of high-value photoelectric imaging targets, it is urgent to develop an optical imaging system with strong anti-laser damage capability and capable of providing continuous anti-laser damage and blinding.

[0003] By improving the optical system, the laser power / energy density on the surface of the imaging detector can be reduced, and the risk of damage and blinding of the optical imaging system by laser can be reduced. In the prior art, a Chinese patent application for invention with publication number CN109931817A and publication date June 25, 2019 and the title of “Anti-laser damage adaptive protection device and optical detection system applying the device” discloses an anti-laser damage technical solution mainly based on a phase change material. In this solution, a beam splitter grating, a protection unit and a beam combining grating are arranged in sequence along the optical path. The protection unit includes a phase change unit and a reflection unit. When the phase change unit is not phase changed, the light can pass through to ensure normal work of the detector. When the incident light power or the temperature of the phase change unit reaches a set threshold, the phase change unit undergoes a semiconductor metal phase change to prevent the light from passing through. The reflection unit is used to reflect and / or scatter the light incident on the unit out of the device. The beam splitter grating projects the light in the working waveband of the detector onto the phase change unit and projects the light outside the working waveband of the detector onto the reflection unit. The beam combining grating is used to combine the light coming out of the beam splitter grating. The beam splitter grating and the beam combining grating are transmission gratings.

[0004] The invention patent application with publication number CN105865268A, publication date August 17, 2016, and invention name "Infrared optical system and method for resisting laser-induced blindness" discloses a technical solution for resisting laser-induced blindness mainly based on a double-probe system. In the solution, the optical system is composed of a common-aperture mid-wave imaging probe unit and a mid-wave laser four-quadrant probe unit. Data switching and steering of the mid-wave imaging probe unit and the mid-wave laser four-quadrant probe unit are realized through a conversion logic device. When the infrared target radiation intensity is less than a certain threshold, the mid-wave imaging probe unit works. When the infrared target radiation intensity reaches a certain threshold, the mid-wave imaging probe unit output image appears saturated and is closed for self-protection, and the mid-wave laser four-quadrant probe unit starts to work. The guidance system switches to the mode of using the four-quadrant probe unit for detection and tracking to continue searching, so as to overcome the problem of blindness caused by laser.

[0005] The invention patent application with publication number CN116931283A, publication date August 17, 2016, and invention name "Photoelectric imaging system with laser protection function" provides a photoelectric imaging system for resisting laser damage mainly based on a wavefront coding element. The system includes an imaging lens, an image sensor, an image processing system, and a cubic vortex phase control element. The cubic vortex phase control element is located between the laser source and the imaging lens and closely contacts the imaging lens to form an equivalent phase plane. When there is no interfering laser, the object image is received by the image sensor after being focused by the imaging lens and modulated by the phase control element. The image sensor sends the received blurred coded image to the image processing system for decoding processing to obtain a clear decoded image, which is then output and displayed. When there is interfering laser, the phase control function of the cubic vortex phase control element can redistribute the energy reaching the image sensor. The light spot at the image sensor is similar to an isosceles triangular spot, the main lobe energy is weakened, and the light intensity maximum position is shifted, thereby reducing the maximum single-pixel receiving power on the image sensor to achieve the purpose of resisting laser damage.

[0006] The above-mentioned three anti-laser-damage blindness solutions have certain effects in resisting continuous laser damage blindness, but have insufficient ability in resisting pulsed laser damage blindness. The main shortcomings include the following aspects:

[0007] (1) Response speed is slow. The optoelectronic countermeasure system or laser ranging system generally uses nanosecond pulse laser as working laser source, and the pulse width is in the order of several nanoseconds to tens of nanoseconds. The main means of "anti-laser damage self-adaptive protection device and optical detection system applying the device" for reducing the laser power / energy density at the imaging detector is high-temperature phase change mechanism of material, and the response time of phase change process is generally in the order of milliseconds, which is greater than the pulse width of nanosecond pulse laser, and cannot make protection response within the action time of laser pulse. The "infrared optical system and method for resisting laser blinding" determines the occurrence of laser interference according to the appearance of saturated spot in the image of middle wave imaging detection unit, and starts the protection mechanism process which needs to go through computer or electronic data processing process such as imaging, image processing, laser interference judgment, conversion logic device operation and guidance mode conversion. The whole processing process takes more than tens of milliseconds, which is greater than the pulse width of nanosecond pulse laser, and cannot make protection response within the action time of laser pulse.

[0008] (2) The protection components or units are damaged after being damaged by pulse laser, and the optical system cannot work normally. The main protection components of "anti-laser damage self-adaptive protection device and optical detection system applying the device" are transmission grating and phase change film. The "infrared optical system and method for resisting laser blinding" has no protection components, and the laser is directly focused on the imaging detector or four-quadrant detector. The main protection component of "optoelectronic imaging system with laser protection function" is a cubic vortex phase control element (the pattern of the cubic vortex phase control element is strictly matched with the rear-end image processing algorithm. If the element is damaged, even if the imaging detector is not damaged, the imaging system cannot correctly decode and obtain a clear decoded image). Most of the above protection components are precision optical elements or imaging detectors themselves, which are easy-to-damage optical devices. Under the condition of high power / energy density laser incidence, the protection components also have damage risk, and the damage of the protection components will lead to the failure of the imaging system. Therefore, in the above technical solutions, if the protection components are damaged, even if the laser disappears, the protection components cannot provide laser protection function for the imaging system, or the imaging system cannot continue to work normally, which has certain defects. SUMMARY

[0009] The present application provides a kind of continuously anti-pulse laser damage blinding optical imaging system to solve the above problems.

[0010] The present application provides a kind of continuously anti-pulse laser damage blinding optical imaging system, comprising: secondary imaging optical system, imaging detector, nonlinear absorption type optical limiting device, two-dimensional moving unit.

[0011] The secondary imaging optical system comprises a primary imaging optical assembly and a secondary imaging optical assembly; after entering the secondary imaging optical system, the light beam is focused by the primary imaging optical assembly to form a primary image plane focal point, and then imaged on an imaging detector by the secondary imaging optical assembly;

[0012] The nonlinear absorption type optical limiting device is installed on a two-dimensional moving unit and placed near the primary image plane position of the primary focal point of the main optical axis of the secondary imaging optical system;

[0013] The nonlinear absorption type optical limiting device is moved by the two-dimensional moving unit, so that the incident light beam passes through different positions on the nonlinear absorption type optical limiting device, thereby realizing the continuous anti-laser damage blinding function.

[0014] Preferably, the two-dimensional moving unit comprises a one-dimensional rotating platform and a one-dimensional linear displacement table; the one-dimensional rotating platform is arranged on the one-dimensional linear displacement table, and the nonlinear absorption type optical limiting device is installed on the one-dimensional rotating platform; the one-dimensional rotating platform and the one-dimensional linear displacement table cooperate to move, so that the incident light beam passes through different positions on the nonlinear absorption type optical limiting device at each moment.

[0015] Preferably, a plurality of sheet-shaped nonlinear absorption type optical limiting devices are installed on the one-dimensional rotating platform, and each nonlinear absorption type optical limiting device has the same or different performance.

[0016] Preferably, a ring-shaped nonlinear absorption type optical limiting device is installed on the one-dimensional rotating platform.

[0017] Preferably, the material of the nonlinear absorption type optical limiting device comprises at least one of phthalocyanine, porphyrin, graphene, fullerene, carbon nanotube, organic small molecule and metal nanoparticle.

[0018] Preferably, the nonlinear absorption type optical limiting device is located on the side of the primary image plane focal point close to the primary imaging optical assembly.

[0019] Preferably, the size of the nonlinear absorption type optical limiting device is greater than the size of the light spot near the primary image plane focal point.

[0020] Preferably, a laser detector is further installed around the system;

[0021] A plurality of sheet-shaped nonlinear absorption type optical limiting devices with different performances are installed on the one-dimensional rotating platform;

[0022] After detecting different system or different wavelength laser incidence, the laser detector provides early warning or laser parameter information to the main system of the continuous anti-pulse laser damage blinding optical imaging system, and the main system automatically controls the rotation of the one-dimensional rotating platform to select nonlinear absorption type optical limiting devices with different performances for protection.

[0023] Preferably, the incident pulsed laser energy density on the surface of the imaging detector is less than the damage / blinding threshold of the imaging detector.

[0024] Preferably, the incident pulsed laser energy density on the surface of the nonlinear absorption type optical limiting device is less than the breakdown threshold of the nonlinear absorption type optical limiting device.

[0025] Compared with the prior art, the present application can achieve the following beneficial effects:

[0026] In view of the problem that the prior art can only resist low-power / energy density continuous laser damage blinding, the present application provides a protection scheme for the optical imaging system to resist pulsed laser damage blinding persistently. The nonlinear absorption type optical limiting device with nanosecond self-response speed is used to effectively reduce the power / energy density of continuous laser and pulsed laser with a pulse width ≥ nanosecond to the surface of the imaging detector, so as to realize automatic protection of the optical imaging system; and after the incident laser disappears, the normal working characteristics of the optical imaging system can be restored. The displacement platform or / and the rotating platform is added to the imaging system, when the incident laser power / energy is large, the nonlinear absorption type optical limiting device is used as a sacrificial material to protect the imaging detector, and the nonlinear absorption type optical limiting device is moved by the displacement platform, so that the laser is irradiated on different positions of the nonlinear absorption type optical limiting device which is not damaged at each moment, thereby realizing persistent laser protection of the imaging detector. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structural schematic diagram of the optical imaging system to resist pulsed laser damage blinding persistently provided according to an embodiment of the present application.

[0028] Figure 2 is a front view schematic diagram of the optical imaging system to resist pulsed laser damage blinding persistently provided according to an embodiment of the present application.

[0029] Figure 3 is an example photo of the nonlinear absorption type optical limiting device provided according to an embodiment of the present application.

[0030] Figure 4 is an input-output energy density curve of the nonlinear absorption type optical limiting device provided according to an embodiment of the present application.

[0031] REFERENCE NUMERALS:

[0032] 1. primary imaging optical assembly;

[0033] 2. secondary imaging optical assembly;

[0034] 3. imaging detector;

[0035] 4. nonlinear absorption type optical limiting device;

[0036] 5. One-dimensional rotating platform;

[0037] 6. One-dimensional linear displacement stage;

[0038] 7. Primary imaging optical system main optical axis. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. In the following description, the same modules are denoted by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0040] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not constitute a limitation on the present application.

[0041] Reference Figures 1-2 As shown in the drawings, the present application provides an optical imaging system for continuous anti-pulse laser damage blindness, comprising: a secondary imaging optical system, an imaging detector 3, a nonlinear absorption type optical limiting device 4, and a two-dimensional moving unit;

[0042] The secondary imaging optical system comprises a primary imaging optical assembly 1 and a secondary imaging optical assembly 2. After the light enters the secondary imaging optical system, it is focused by the primary imaging optical assembly 1 to form a primary image plane focal point, and then imaged on the imaging detector 3 by the secondary imaging optical assembly 2;

[0043] The nonlinear absorption type optical limiting device 4 is installed on the two-dimensional moving unit and placed near the primary image plane position of the secondary imaging optical system main optical axis 7;

[0044] Specifically, the nonlinear absorption type optical limiting device 4 is located on the side of the primary image plane focal point close to the primary imaging optical assembly 1, and its position relative to the primary image plane focal point needs to be accurately designed to ensure its working performance;

[0045] Specifically, the two-dimensional moving unit comprises a one-dimensional rotating platform 5 and a one-dimensional linear displacement stage 6; the one-dimensional rotating platform 5 is arranged on the one-dimensional linear displacement stage 6; the nonlinear absorption type optical limiting device 4 is installed on the one-dimensional rotating platform 5; the one-dimensional rotating platform 5 and the one-dimensional linear displacement stage 6 cooperate to move, so that the incident light beam passes through different positions on the nonlinear absorption type optical limiting device 4 at each moment.

[0046] The typical material of the nonlinear absorption type optical limiting device 4 can be, but is not limited to, phthalocyanine, porphyrin, graphene, fullerene, carbon nanotube, organic small molecule or metal nanoparticle and the like.

[0047] The spot size near the primary image plane focal point on the primary optical axis 7 of the secondary imaging optical system is far smaller than the size of the nonlinear absorption type optical limiting device 4. The small spot can move on the nonlinear absorption type optical limiting device 4 by the cooperation of the one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6. The translation step and speed need to be designed according to the size of the damage spot in the preliminary test.

[0048] The front view of the optical imaging system for continuously resisting the laser-induced blindness is shown in Figure 2

[0049] In a specific embodiment, the one-dimensional rotating platform 5 can be installed with multiple nonlinear absorption type optical limiting devices 4. The one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6 are controlled by programming to move the nonlinear absorption type optical limiting device 4 in a small step two-dimensional motion perpendicular to the primary optical axis 7 of the secondary imaging optical system. When the primary system determines that the nonlinear absorption type optical limiting device 4 is damaged and cannot be used or the protection parameters are not suitable, the one-dimensional rotating platform 5 is rotated in a large range to place another nonlinear absorption type optical limiting device 4 on the primary optical axis 7 of the secondary imaging optical system. Then the one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6 control the nonlinear absorption type optical limiting device 4 to move in a small step two-dimensional motion again. In this way, the primary optical axis 7 of the secondary imaging optical system passes through different positions of the nonlinear absorption type optical limiting device 4 at each moment, and the function of continuously resisting the laser-induced blindness of the secondary imaging optical system is realized.

[0050] In a specific embodiment, the nonlinear absorption type optical limiting device 4 is typically in the shape of a circular thin sheet (as shown in Figure 3 The primary optical axis 7 of the secondary imaging optical system passes through the nonlinear absorption type optical limiting device 4.

[0051] In a specific embodiment, according to the actual production process changes, the nonlinear absorption type optical limiting device 4 can be prepared in a large size. For example, the nonlinear absorption type optical limiting device 4 can be made into a ring structure, and the installation method on the one-dimensional rotating platform 5 is adjusted accordingly. At the same time, the motion method of the one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6 will change. The one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6 can be replaced by a two-dimensional linear displacement table to realize the position change of the nonlinear absorption type optical limiting device 4 relative to the primary optical axis 7 of the secondary imaging optical system.

[0052] In a specific embodiment, since the optical imaging system for continuously resisting the laser-induced blindness has protection requirements for different systems or different wavelengths of laser, multiple nonlinear absorption type optical limiting devices with different performances can be installed on the one-dimensional rotating platform 5. During the work, different nonlinear absorption type optical limiting devices are selected by rotating the one-dimensional rotating platform 5.

[0053] ​Further, the position of the nonlinear absorption optical limiting device 4 relative to the primary image plane needs to be precisely designed. Since the nonlinear absorption optical limiting material mainly exhibits the following three working characteristics under the action of laser:

[0054] (1) Linear absorption characteristic (the pulse laser energy density incident on the front surface of the nonlinear absorption optical limiting device 4 is 0~XJ / cm 2 ), in which case the energy density F1 incident on the nonlinear absorption optical limiting device 4 and the energy density F2 transmitted through the nonlinear absorption optical limiting device 4 substantially satisfy the linear proportional relationship: F2 / F1=A<1;

[0055] (2) Nonlinear absorption characteristic (the incident pulse laser energy density is XJ / cm 2 ~YJ / cm 2 ), in which case as the incident pulse laser energy density F1 increases, the ratio F2 / F1 decreases, and then, after the incident pulse laser disappears, the nonlinear absorption optical limiting device 4 can restore the linear absorption characteristic;

[0056] (3) Damage characteristic (the incident pulse laser energy density≥YJ / cm 2 , and the damage threshold of the nonlinear absorption optical limiting device 4 is defined as YJ / cm 2 ), in which case the nonlinear absorption optical limiting device 4 first exhibits nonlinear absorption characteristics, then is damaged, and after the incident pulse laser disappears, the linear absorption characteristic cannot be restored.

[0057] Based on the above working characteristics of the nonlinear absorption optical limiting device 4, the position of the nonlinear absorption optical limiting device 4 relative to the primary image plane can be designed according to the performance index requirements of the anti-laser damage blinding optical imaging system for normal operation and anti-laser damage blinding, and then the spot size of the laser beam on the surface of the nonlinear absorption optical limiting device 4 is controlled, so as to make the incident pulse laser energy density F1 on the surface of the nonlinear absorption optical limiting device 4<YJ / cm 2 , and the incident pulse laser energy density F3 on the surface of the imaging detector is<the damage / blinding threshold of the imaging detector ZJ / cm 2 ; in the case where the above two conditions cannot be met simultaneously, the incident pulse laser energy density F3 on the surface of the imaging detector is preferentially ensured to be<the damage / blinding threshold of the imaging detector ZJ / cm 2 .

[0058] Further, a laser detector can be installed around the optical imaging system resistant to blindness caused by persistent anti-pulse laser damage, and after detecting laser of different systems or different wavelengths, the main system of the optical imaging system resistant to blindness caused by persistent anti-pulse laser damage is provided with early warning or laser parameter information, and the main system automatically controls the one-dimensional rotating platform 5 to rotate and select nonlinear absorption type optical limiting devices with different performances. The above improvement scheme can further expand the application range of the optical imaging system resistant to blindness caused by laser damage.

[0059] The anti-laser protection scheme of the present application is not limited to the application range described in the present application, and can also be applied to other photoelectric detection systems.

[0060] Embodiment 1

[0061] The present embodiment provides an optical imaging system resistant to blindness caused by persistent anti-pulse laser damage, comprising: a primary imaging optical assembly 1, a secondary imaging optical assembly 2, an imaging detector 3, a nonlinear absorption type optical limiting device 4, a one-dimensional rotating platform 5, and a one-dimensional linear displacement table 6.

[0062] After the light enters the optical system, it is focused by the primary imaging optical assembly 1 to form a primary image focal point, and then imaged on the imaging detector 3 by the secondary imaging optical assembly 2.

[0063] The nonlinear absorption type optical limiting device 4 is installed on the one-dimensional rotating platform 5, and the main optical axis 7 of the secondary imaging optical system passes through the nonlinear absorption type optical limiting device 4; the nonlinear absorption type optical limiting device 4 is located on the side of the primary image focal point close to the primary imaging optical assembly 1.

[0064] The one-dimensional rotating platform 5 is installed with multiple nonlinear absorption type optical limiting devices 4; the material of the nonlinear absorption type optical limiting device 4 is phthalocyanine (such as Figure 3 The protective material prepared from phthalocyanine materials is shown in the left).

[0065] Further, a laser detector can be installed around the optical imaging system resistant to blindness caused by persistent anti-pulse laser damage, and after detecting laser of different systems or different wavelengths, the main system of the optical imaging system resistant to blindness caused by persistent anti-pulse laser damage is provided with early warning or laser parameter information, and the main system automatically controls the one-dimensional rotating platform 5 to rotate and select nonlinear absorption type optical limiting devices with different performances. The above improvement scheme can further expand the application range of the optical imaging system resistant to blindness caused by laser damage.

[0066] (1) In the absence of laser incidence, the nonlinear absorption type optical limiting device 4 maintains linear working characteristics, and the optical imaging system resistant to blindness caused by persistent anti-pulse laser damage normally performs imaging work tasks.

[0067] (2) The damage threshold of the nonlinear absorption type optical limiting device 4 is defined as YJ / cm 2 ; when laser is incident and the incident pulse laser energy density F1 < YJ / cm 2In this case, the nonlinear absorption type optical limiting device 4 automatically exhibits nonlinear absorption characteristics, and the optical path of the persistent anti-pulse laser damage blinding optical imaging system is basically in a closed state, and the imaging system is equivalent to stop working; after the incident laser disappears, the nonlinear absorption type optical limiting device 4 restores the linear working state, the optical path of the imaging system is reopened, and the persistent anti-pulse laser damage blinding optical imaging system continues to perform the imaging work task.

[0068] (3) When the laser is incident and the incident pulse laser energy density F1≥Y J / cm 2 In this case, the nonlinear absorption type optical limiting device 4 surface appears damage, but due to the one-dimensional rotating platform 5 and the one-dimensional linear displacement table 6 moving the undamaged area of the nonlinear absorption type optical limiting device 4 surface to the imaging system main light path at the next moment, the nonlinear absorption type optical limiting device 4 continues to provide laser protection for the imaging system, at this time the optical path of the persistent anti-pulse laser damage blinding optical imaging system continues to be in a closed state; after the incident laser disappears, the nonlinear absorption type optical limiting device 4 restores the linear working state, the optical path of the imaging system is reopened, and the persistent anti-pulse laser damage blinding optical imaging system continues to perform the imaging work task.

[0069] The laser is used to test the optical limiting effect of the nonlinear absorption type optical limiting device; the test laser parameters are as follows: the laser is a diode pumped Q-switched Nd:YAG pulse laser of Quantel Big Sky Centurion Company, the wavelength is 532 nm, the pulse width is 8 ns, the repetition frequency is 1-100 Hz, and the experiment is set to 10 Hz.

[0070] The test results are shown in FIG. 8. Figure 4 As shown in the figure, the horizontal coordinate is the incident laser energy density of the nonlinear absorption type optical limiting device, and the vertical coordinate is the transmitted laser energy density of the nonlinear absorption type optical limiting device. From the figure, it can be seen that as the incident laser energy density increases, the ratio of the transmitted energy density to the incident energy density decreases obviously. It is proved that the nonlinear absorption type optical limiting device can play a nonlinear optical limiting role in nanosecond level.

[0071] In summary, the application provides an optical imaging system for continuous anti-pulse laser damage blindness, which mainly comprises a secondary imaging optical system, a nonlinear absorption light limiting device, a two-dimensional moving unit and an imaging detector.

[0072] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present disclosure can be achieved, which is not limited herein.

[0073] The above detailed description does not constitute a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An optical imaging system resistant to continuous anti-pulse laser damage blindness, characterized in that, The application relates to a persistent anti-pulse laser damage blinding optical imaging system. The persistent anti-pulse laser damage blinding optical imaging system comprises a secondary imaging optical system, an imaging detector, a nonlinear absorption type optical limiting device and a two-dimensional moving unit. The secondary imaging optical system comprises a primary imaging optical assembly and a secondary imaging optical assembly; after entering the secondary imaging optical system, a light beam is focused by the primary imaging optical assembly to form a primary image plane focus, and then is imaged on the imaging detector by the secondary imaging optical assembly. The nonlinear absorption type optical limiting device is installed on the two-dimensional moving unit and is arranged near the primary image plane position of the main optical axis of the secondary imaging optical system. The movement of the nonlinear absorption type optical limiting device is driven by the two-dimensional moving unit, so that the incident light beam passes through different positions on the nonlinear absorption type optical limiting device, and the persistent anti-laser damage blinding function is realized; the two-dimensional moving unit comprises a one-dimensional rotating platform and a one-dimensional linear displacement table; the one-dimensional rotating platform is arranged on the one-dimensional linear displacement table, and the nonlinear absorption type optical limiting device is installed on the one-dimensional rotating platform; the one-dimensional rotating platform and the one-dimensional linear displacement table are movably connected, so that the incident light beam passes through different positions on the nonlinear absorption type optical limiting device at each moment.

2. The optical imaging system of claim 1, wherein: A plurality of groups of sheet-shaped nonlinear absorption type optical limiting devices are installed on the one-dimensional rotating platform, and the performance of each nonlinear absorption type optical limiting device is the same or different.

3. The optical imaging system of claim 1, wherein: An annular nonlinear absorption type optical limiting device is installed on the one-dimensional rotating platform.

4. The optical imaging system of claims 1-3, wherein: The material of the nonlinear absorption type optical limiting device comprises at least one of phthalocyanine, porphyrin, graphene, fullerene, carbon nanotube, organic small molecule and metal nanoparticle.

5. The optical imaging system of claim 1, wherein: The nonlinear absorption type optical limiting device is located on the side of the primary image plane focus close to the primary imaging optical assembly.

6. The optical imaging system of claim 5, wherein: The size of the nonlinear absorption type optical limiting device is greater than the size of the light spot near the primary image plane focus.

7. The optical imaging system of claim 1, wherein, A laser detector is installed around the system. A plurality of groups of sheet-shaped nonlinear absorption type optical limiting devices with different performances are installed on the one-dimensional rotating platform. After detecting different system or different wavelength laser incidence, the laser detector provides early warning or laser parameter information to the main system of the persistent anti-pulse laser damage blinding optical imaging system, and the main system automatically controls the rotation of the one-dimensional rotating platform to select nonlinear absorption type optical limiting devices with different performances for protection.

8. The optical imaging system of claim 1, wherein: The incident pulse laser energy density on the surface of the imaging detector is less than the damage / blinding threshold of the imaging detector.

9. The optical imaging system of claim 8, wherein: The incident pulse laser energy density on the surface of the nonlinear absorption type optical limiting device is less than the breakdown threshold of the nonlinear absorption type optical limiting device.

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