Space coupling and real-time monitoring compensation device and method based on single-photon detector

Abstract

The invention discloses a space coupling and real-time monitoring compensation device and method based on a single photon detector. The device comprises a single-photon detector (1), an aspheric focusing lens (2), a first beam splitter (3), a first long-line-of-sight camera (4), a second long-line-of-sight camera (5), a second beam splitter (6), a collimation compensation lens group (7), a parallel light source (8) and a telescope system (9). In the calibration mode, focusing calibration and optical axis calibration of the aspheric focusing lens on the target surface of the single-photon detector are realized; a part of light reflected by the first beam splitter to the parallel light beams reaches the second long line-of-sight camera to form an image point, and the image point serves as a calibration point of the target surface of the single-photon detector and the optical axis of the aspheric focusing lens and focusing calibration; when the accessed parallel light beams diverge or deviate, compensation is realized by adjusting the collimation compensation lens group. According to the invention, through real-time monitoring compensation, stable photon receiving efficiency of the laser ranging system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection technology, and in particular to a spatial coupling and real-time monitoring compensation device and method based on a single-photon detector. Background Art

[0002] With the development of human space exploration and aerospace technology, human activities in space have been increasing, but more and more space debris has been generated. Space debris refers to all man-made objects in orbit except for normal spacecraft, including rocket bodies and satellite bodies that have completed their missions, rocket ejecta, discarded objects in the process of performing space missions, and debris generated by collisions between space objects, also known as "space junk". At present, there are hundreds of millions of space debris above the millimeter level in space, with a total amount of several thousand tons. Tens of thousands of spacecraft have been launched into the air around the world, and they may fall into the earth at any time. Space debris above the centimeter level can cause complete damage to spacecraft, while the cumulative impact effect of millimeter-level or micron-level space debris will cause spacecraft performance degradation or functional failure. The existence of space debris seriously threatens the safety of spacecraft in orbit, and the continuous generation of space debris also poses a serious threat to limited orbital resources.

[0003] Single-photon detectors can respond to single photons and have high sensitivity. They are very suitable for receiving weak light signals. They are usually used as laser echo receivers to detect laser echoes reflected by long-distance satellites / space debris. Laser ranging based on single-photon detectors has the advantages of long-range measurement and high accuracy, making it a conventional means of high-precision orbit determination of space debris and is used to better monitor the orbits of satellites / space debris. In the laser ranging system, the laser beam needs to be able to accurately emit lasers to aim at space debris. Space debris will reflect the emitted laser back to the ground, which will then be received by the receiving telescope of the laser ranging system and finally detected by the single-photon detector of the laser ranging system, outputting an echo signal to achieve laser ranging.

[0004] Since space debris is far away from the earth's surface and moves very fast, it is difficult to launch lasers to aim at space debris and capture lasers reflected by space debris. At the same time, since the detection target surface of single-photon detectors is generally small (~100um), it is difficult for the laser echo coupled by the ranging telescope system to enter the target surface of the single-photon detector. At the same time, the telescope system is affected by environmental or human factors, and the mechanical structure and optical path of the telescope system change frequently, which makes the laser echo coupled into the single-photon detector deviate greatly, and the receiving efficiency of the single-photon detector decreases significantly, and even deviates from the target surface of the single-photon detector, and cannot be effectively detected.

[0005] Therefore, how to compensate for slight changes in the telescope system, ensure the stability of the spatial coupling of the single-photon detector, and maintain the high-efficiency detection of the single-photon detector has become a technical problem that needs to be solved. Summary of the invention

[0006] The purpose of the present invention is to provide a spatial coupling and real-time monitoring compensation device and method based on a single-photon detector, which is used to achieve compensation for slight changes in the telescope system, ensure the stability of the spatial coupling of the single-photon detector, and maintain the high-efficiency detection of the single-photon detector.

[0007] To achieve the above object, the present invention provides the following technical solutions: According to one aspect of the present invention, a spatial coupling and real-time monitoring compensation device based on a single-photon detector is provided, comprising: a single-photon detector 1, an aspheric focusing lens 2, a first beam splitter 3, a first telescopic camera 4, a second telescopic camera 5, a second beam splitter 6, a collimating compensation lens group 7, a parallel light source 8 and a telescope system 9; the collimating compensation lens group 7 comprises a concave lens 71 and a convex lens 72; In the calibration mode, the parallel light source 8 emits a parallel light beam, and the parallel light beam reaches the target surface of the single-photon detector 1 along the collimating compensation lens group 7, the second beam splitter 6, the first beam splitter 3, and the aspheric focusing lens 2 configured along the horizontal common optical axis. The parallel reflected light beam obtained after reflection from the target surface reaches the second beam splitter 6 along the aspheric focusing lens 2 and the first beam splitter 3 configured along the horizontal common optical axis, and is split by the second beam splitter 6 to obtain a first part of the parallel reflected light beam perpendicular to the optical axis; the first telescopic camera 4 images the first part of the parallel reflected light beam to obtain the target surface image of the single-photon detector 1; the aspheric focusing lens 2 is adjusted to make the target surface of the single-photon detector 1 The image of the surface is clear in the first telescopic camera 4, and the focus calibration of the aspheric focusing lens 2 on the target surface of the single-photon detector 1 is realized; by adjusting the single-photon detector 1 so that the target surface of the single-photon detector 1 is at the center of the imaging area of ​​the first telescopic camera 4, the optical axis calibration of the target surface of the single-photon detector 1 and the aspheric focusing lens 2 is realized; the parallel light beam of the parallel light source 8 is reflected and split by the first beam splitter 3 to obtain a first part of the parallel light beam, which arrives at the second telescopic camera 5 along the vertical optical axis to form a parallel light image point, and the parallel light image point is used as the calibration point of the optical axis calibration and focus calibration of the target surface of the single-photon detector 1 and the aspheric focusing lens 2; In the compensation mode, the first telescopic camera 4, the second beam splitter 6 and the parallel light source 8 are removed, and the telescope system 9 is connected as the parallel light source; the telescope system 9 tracks the star image at the imaging point of the second telescopic camera 5 as the calibration point for the optical axis calibration and focus calibration of the target surface of the single-photon detector 1 and the aspheric focusing lens 2; after the optical system of the telescope system 9 is affected by environmental or human factors, the star image monitored by the second telescopic camera 5 will be deteriorated, that is, the aspheric focusing lens 2 will focus the parallel light on the spot of the single-photon detector 1 will be deteriorated, at this time, by adjusting the concave lens 71 and the convex lens 72 in the collimating compensation lens group 7, the star image in the second telescopic camera 5 is imaged to occupy the minimum number of pixels, thereby realizing the real-time monitoring and compensation of the high-precision spatial coupling of the single-photon detector connected to the telescope system 9.

[0008] According to one embodiment of the present invention, the single-photon detector 1 can be adjusted forward and backward, up and down, left and right, and in pitch, and is used for alignment adjustment of the optical axis. It has a locking function and can be stably locked after adjustment; the aspheric focusing lens 2 can be adjusted forward and backward and can be locked after adjustment.

[0009] According to one embodiment of the present invention, the single-photon detector has an adjustment range of 2 to 5 mm in up, down, left, and right directions, a pitch adjustment range of 0 to 10°, and a front and back adjustment range of 2 to 10 mm.

[0010] According to an embodiment of the present invention, the reflectivity of the first beam splitter 3 to the parallel light beam of the parallel light source 8 is 1% to 3%, and the transmittance is greater than or equal to 95%.

[0011] According to an embodiment of the present invention, the reflectivity of the second beam splitter 6 to the parallel light beam of the parallel light source is 50%, and the transmittance is 50%.

[0012] According to one embodiment of the present invention, the quotient of the focal length of the convex lens 72 divided by the focal length of the concave lens 71 is greater than or equal to the quotient of the size of the beam of the parallel light source or the telescope system irradiating the convex lens and the aperture of the aspheric focusing lens.

[0013] According to one embodiment of the present invention, the quotient of the focal length of the convex lens divided by the focal length of the concave lens can be 2 to 10; the quotient of the beam size of the parallel light source or the parallel light beam of the telescope system irradiating the convex lens and the clear aperture of the aspheric focusing lens is 1.1 to 1.5 times.

[0014] According to an embodiment of the present invention, the spot size of the parallel light beam is 10 to 100 mm.

[0015] According to one embodiment of the present invention, the first telescopic camera 4 includes a first focusing lens 41 and a first camera 42; the resolution of the first telescopic camera 4 is the pixel size of the first camera 42 divided by the focal length of the first focusing lens 41; the second telescopic camera 5 includes a second focusing lens 51 and a second camera 52; the resolution of the second telescopic camera 5 is the pixel size of the second camera 52 divided by the focal length of the second focusing lens 51.

[0016] On the other hand, the present invention also provides a spatial coupling and real-time monitoring compensation method based on a single-photon detector, the method comprising the following steps: After the parallel light source emits a parallel light beam and passes through the collimating compensation lens group, the parallel light beam passes through the second beam splitter, the first beam splitter, and the aspheric focusing lens to the target surface of the single-photon detector. The single-photon detector reflects the parallel light beam to the second beam splitter, and part of the light is received by the first telescopic camera. The first telescopic camera images the target surface of the single-photon detector. The aspheric focusing lens is adjusted so that the target surface of the single-photon detector is clearly imaged in the first telescopic camera, thereby realizing the focus calibration of the aspheric focusing lens on the target surface of the single-photon detector. The single-photon detector is adjusted so that the target surface of the single-photon detector is centered in the imaging area of ​​the first telescopic camera, so as to achieve optical axis calibration between the target surface of the single-photon detector and the aspherical focusing lens; The first beam splitter reflects part of the light of the parallel light beam to the second telescopic camera to form an image point, and the image point is used as a calibration point for the optical axis calibration and focus calibration of the single-photon detector target surface and the aspheric focusing lens; When the received parallel light beam diverges or the light beam deviates, the image point formed by the second telescopic camera becomes larger or deviates from the calibration point, and compensation is achieved by adjusting the collimation compensation lens group.

[0017] The present invention provides a spatial coupling and real-time monitoring compensation device and method based on a single-photon detector, which monitors the optical axis and focus of an aspheric focusing lens focusing parallel light onto a single-photon detector through a long-distance camera, and monitors the optical deviation of a connected telescope system in real time, and performs real-time compensation by adjusting a collimating compensation lens group.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. Using the first telescopic camera, parallel light is incident on the aspheric focusing lens and the single-photon detector to achieve high-precision adjustment and calibration of the optical axis and focus adjustment process of the aspheric focusing lens focusing the parallel light onto the single-photon detector.

[0019] 2. Use the second telescopic camera and collimating compensating lens group to monitor the parallel light entering distant stars through the telescope system in real time. When the changes in the star image emission of the telescope system for star observation are monitored, the collimating compensating lens group is adjusted to compensate for the slight changes in the telescope system.

[0020] 3. Use a beam splitter to form multiple light paths and achieve an equivalent constant light path for each light path. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 1 is an optical path diagram of a spatial coupling and real-time monitoring compensation device based on a single-photon detector in a calibration mode according to an exemplary embodiment of the present invention.

[0022] Figure 2 1 is an optical path diagram of a compensation device based on spatial coupling and real-time monitoring of single-photon detectors in a compensation mode according to an exemplary embodiment of the present invention.

[0023] Reference numerals: 1-single photon detector; 2-aspheric focusing lens; 3-first beam splitter; 4-first telephoto camera; 41-first focusing lens; 42-first camera; 5-second telephoto camera; 51-second focusing lens; 52-second camera; 6-second beam splitter; 7-collimating compensation lens group; 71-concave lens; 72-convex lens; 8-parallel light source; 9-telescope system; 91-condenser; 92-collimator; 93-reflector. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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.

[0027] A spatial coupling and real-time monitoring compensation device based on a single-photon detector according to an embodiment of the present invention comprises: a single-photon detector 1, an aspheric focusing lens 2, a first beam splitter 3, a first telescopic camera 4, a second telescopic camera 5, a second beam splitter 6, a collimating compensation lens group 7, a parallel light source 8 and a telescope system 9.

[0028] The first telescopic camera 4 includes a first focusing lens 41 and a first camera 42 ; the second telescopic camera 5 includes a second focusing lens 51 and a second camera 52 ; the collimating compensation lens group 7 includes a concave lens 71 and a convex lens 72 .

[0029] like Figure 1 As shown, in the calibration mode, the device uses a parallel light source 8 to emit a parallel light beam, and the parallel light beam reaches the target surface of the single-photon detector 1 along the collimating compensation lens group 7, the second beam splitter 6, the first beam splitter 3, and the aspheric focusing lens 2 configured along the horizontal common optical axis; The parallel light beam is reflected by the target surface of the single-photon detector 1 to obtain a parallel reflected light beam, and the parallel reflected light beam reaches the second beam splitter 6 along the aspheric focusing lens 2 and the first beam splitter 3 configured along the horizontal common optical axis; the parallel reflected light beam is split by the second beam splitter 6 to obtain a first part of parallel reflected light beams perpendicular to the optical axis; the first part of the parallel reflected light beam reaches the first telescopic camera 4, and the first telescopic camera 4 images the target surface of the single-photon detector 1; By adjusting the aspheric focusing lens 2, the image of the target surface of the single-photon detector 1 in the first long-distance camera 4 is clear, so as to achieve the focus calibration of the aspheric focusing lens 2 on the target surface of the single-photon detector 1; The single-photon detector 1 is adjusted so that the target surface of the single-photon detector 1 is at the center of the imaging area of ​​the first telescopic camera 4, and the optical axis calibration between the target surface of the single-photon detector 1 and the aspherical focusing lens 2 is achieved; The parallel light beam of the parallel light source 8 is reflected and split by the first beam splitter 3 to obtain a first part of the parallel light beam, which arrives at the second telescopic camera 5 along the vertical optical axis to form a parallel light image point, and the parallel light image point is used as a calibration point for the optical axis calibration and focus calibration of the target surface of the single-photon detector 1 and the aspheric focusing lens 2.

[0030] The single photon detector 1 can be adjusted forward and backward, up and down, left and right, and pitched, and is used for the alignment adjustment of the horizontal optical axis, and has a locking function, and can be stably locked after adjustment to prevent loosening. The single photon detector can be adjusted up and down, left and right in a range of 2 to 5 mm, in a pitch adjustment range of 0 to 10°, and in a range of 2 to 10 mm in a front and back adjustment range.

[0031] The aspheric focusing lens 2 can be adjusted forward and backward. By adjusting forward and backward, the light beam of the parallel light source 8 can be focused on the target surface of the single-photon detector 1, and can be locked after adjustment.

[0032] The reflectivity of the first beam splitter 3 to the parallel light beam of the parallel light source 8 is 1% to 3%, and the transmittance is greater than or equal to 95%, so that an absolute part of the parallel light beam of the parallel light source 8 is imaged on the single-photon detector 1, and a small part is imaged on the second telescopic camera 5.

[0033] The second beam splitter 6 has a reflectivity of 50% and a transmittance of 50% for the parallel light source, and is used to split the parallel light beam of the parallel light source 8 into a first parallel light beam and a second parallel light beam, and ensure that the parallel light reflected back from the target surface of the single-photon detector has sufficient intensity to reach the first telescopic camera 4.

[0034] like Figure 2 As shown, the device is in compensation mode, removing Figure 1 The first telescopic camera 4, the second beam splitter 6 and the parallel light source 8 are connected to a telescope system 9. The telescope system 9 is used as a parallel light source. The telescope system 9 tracks stars. At this time, the parallel light beam is the star image (star parallel light imaging). The star image image point of the second telescopic camera 5 is used as the calibration point for the optical axis calibration and focus calibration of the single photon detector 1 target surface and the aspheric focusing lens 2; exist Figure 2 In the figure, an exemplary telescope system is given, which includes a condenser 91, a collimator 92, and a reflector 93. The stellar image is condensed by the condenser 91 and collimated by the collimator 92 to obtain stellar image parallel light. The reflector 93 reflects the stellar image parallel light and enters the horizontal optical axis, and reaches the target surface of the single-photon detector 1 as a parallel light beam.

[0035] After the optical system of the telescope system 9 is affected by environmental or human factors, the star image monitored by the second telescopic camera 5 will deteriorate, that is, the spot of the single-photon detector 1 focused by the aspherical focusing lens 2 on the parallel light will deteriorate. At this time, by adjusting the concave lens 71 and the convex lens 72 in the collimating compensation lens group 7, the star image in the second telescopic camera 5 is optimally imaged with the minimum number of pixels occupied, thereby realizing real-time monitoring and compensation of high-precision spatial coupling of the single-photon detector connected to the telescope system 9.

[0036] The quotient of the focal length of the convex lens 72 divided by the focal length of the concave lens 71 is greater than or equal to the quotient of the beam size of the parallel light beam of the parallel light source 8 or the telescope system 9 irradiated onto the convex lens 72 and the clear aperture of the aspheric focusing lens 2, ensuring that the parallel light beams passing through the concave lens 71 and the convex lens 72 can all pass through the aspheric focusing lens 2 and be focused onto the single-photon detector 1. The quotient of the focal length of the convex lens 72 divided by the focal length of the concave lens 71 can be 2 to 10. The quotient of the beam size of the parallel light beam of the parallel light source 8 or the telescope system 9 irradiated onto the convex lens 72 and the clear aperture of the aspheric focusing lens 2 can be 1.1 to 1.5 times. The spot size of the parallel light beam can be set to 10 to 100 mm.

[0037] When the device is in calibration mode or compensation mode, when the parallel light beam of the connected parallel light source 8 or telescope system 9 diverges or shifts, the image point formed by the second telescopic camera 5 becomes larger or shifts the calibration point, and the parallel light image point meets the requirements of being a calibration point by adjusting the collimating compensation lens group 7.

[0038] The first telescopic camera 4 includes a first focusing lens 41 and a first camera 42; the resolution of the first telescopic camera 4 is the pixel size of the first camera 42 divided by the focal length of the first focusing lens 41; the second telescopic camera 5 includes a second focusing lens 51 and a second camera 52; the resolution of the second telescopic camera 5 is the pixel size of the second camera 52 divided by the focal length of the second focusing lens 51.

[0039] The existing coupling technology for single-photon detectors can only achieve spatial coupling, connecting the photons in free space to the single-photon detector, especially in laser detection, coupling the photons of the laser echo signal into the single-photon detector to achieve high-sensitivity detection. However, the coupling efficiency and stability are not guaranteed in this process, and the existing technology does not provide a better method or device for this. The spatial coupling and real-time monitoring compensation device of the single-photon detector of the present invention provides a better spatial coupling method for the photon reception of the single-photon detector, and can perform real-time monitoring and compensation. By monitoring the quality of the imaging image points of the parallel light incident on the single-photon detector, it can be timely discovered whether the telescope system has deviations. After the deviation occurs, the concave lens 71 and the convex lens 72 in the collimation compensation lens group 7 can be adjusted in time to compensate for the imaging deviation, which can effectively solve the problem of stable detection of spatial light by the single-photon detector.

[0040] A spatial coupling and real-time monitoring compensation method based on a single-photon detector comprises the following steps: After the parallel light source emits a parallel light beam and passes through the collimating compensation lens group, the parallel light beam passes through the second beam splitter, the first beam splitter, and the aspheric focusing lens to the target surface of the single-photon detector. The single-photon detector reflects the parallel light beam to the second beam splitter, and part of the light is received by the first telescopic camera. The first telescopic camera images the target surface of the single-photon detector. The aspheric focusing lens is adjusted so that the target surface of the single-photon detector is clearly imaged in the first telescopic camera, thereby realizing the focus calibration of the aspheric focusing lens on the target surface of the single-photon detector. The single-photon detector is adjusted so that the target surface of the single-photon detector is at the center of the imaging area of ​​the first telescopic camera, so as to realize the optical axis calibration of the target surface of the single-photon detector and the aspheric focusing lens; the first beam splitter forms an image point for part of the light reflected by the parallel light beam to the second telescopic camera, and the image point is used as the calibration point for the optical axis and focus calibration of the target surface of the single-photon detector and the aspheric focusing lens; When the received parallel light beam diverges or the light beam deviates, the image point formed by the second telescopic camera becomes larger or deviates from the calibration point, and compensation is achieved by adjusting the collimation compensation lens group.

[0041] In a specific implementation, the single-photon detector matches the wavelength response of the detected response photons according to the actual measurement needs. The device meets the required measured wavelength for coupling and monitoring. The corresponding devices (optical lens size, shape), etc. are limited by the size of the connected parallel light beam spot. If the spot of the external parallel light beam (telescope system) is large, the corresponding device size is also large. If it is small, the corresponding size is also small, so that the spot of the parallel light beam of different telescope systems can be coupled to the single-photon detector through the device of the present invention.

[0042] The existing single telescopic camera lacks monitoring of the working optical path because there is no second telescopic camera in the working optical path. At the same time, due to the lack of collimating compensation lens group, the working optical path lacks compensation function due to environmental or human factors during testing.

[0043] In the technical solution of the present invention, in the calibration mode, two telescopic cameras are used, one telescopic camera monitors the light spot after the parallel light is spatially coupled to the single-photon detector, and the other telescopic camera monitors the parallel light beam. For the same path of parallel light, the light spot after the parallel light is spatially coupled to the single-photon detector is calibrated and marked on the monitored parallel light beam; in the compensation mode, the working light path only uses one telescopic camera to monitor the working light path. When the working light path, that is, the telescopic camera monitors the light spot after the parallel light is spatially coupled to the single-photon detector, the telescopic camera is not used, thereby reducing the attenuation of the number of photons of the working light (50% attenuation). The working light path is monitored by a camera that monitors the parallel light beam, and the monitoring situation of the working light path and the effect of the parallel light beam monitoring are analyzed to determine whether there is a problem with the working light path. If there is a problem, the collimation compensation mirror group is adjusted to ensure that the working light path has good consistency with the parallel light path adjusted by the calibration, thereby ensuring that the working light path can be well coupled into the single-photon detector.

[0044] The image point formed by the working optical path in the second telescopic camera is compared with the calibrated image point size (pixel size). If the deviation between the two sizes is large, for example, greater than the first deviation threshold, it is necessary to first perform a large-scale coarse adjustment of the collimation compensation mirror to make the image point smaller than or equal to the first deviation threshold. If it is still greater than the second deviation threshold after being reduced, then perform a small-scale fine adjustment to ensure that the image point is smaller than the target threshold size. The smaller the image point size after collimation compensation, the better. If the deviation between the image point size after collimation compensation and the calibrated image point size is not large, for example, greater than the second deviation threshold, then fine-tune the collimation compensation mirror to ensure that the image point is within the range of less than the target threshold size, the smaller the better.

[0045] The calibration accuracy of the optical axis is determined by the focusing lens of the telescopic camera and the pixel size of the camera, which can form a higher accuracy (pixel size divided by the focal length of the focusing lens). For example, if the pixel size is 2.5um and the focal length is 100mm, the corresponding accuracy can theoretically reach 25urad.

[0046] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the specification. Certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0047] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the present invention and its equivalents.

Claims

1. A spatial coupling and real-time monitoring compensation device based on a single-photon detector, characterized in that: include: A single-photon detector (1), an aspheric focusing lens (2), a first beam splitter (3), a first telescopic camera (4), a second telescopic camera (5), a second beam splitter (6), a collimating compensation lens group (7), a parallel light source (8) and a telescope system (9); the collimating compensation lens group (7) comprises a concave lens (71) and a convex lens (72); In a calibration mode, a parallel light source (8) emits a parallel light beam, and the parallel light beam reaches the target surface of the single-photon detector (1) along a collimating compensation lens group (7), a second beam splitter (6), a first beam splitter (3), and an aspheric focusing lens (2) arranged on a horizontal common optical axis. The parallel reflected light beam obtained after being reflected from the target surface reaches the second beam splitter (6) along an aspheric focusing lens (2) and a first beam splitter (3) arranged on the horizontal common optical axis, and is split by the second beam splitter (6) to obtain a first portion of parallel reflected light beams perpendicular to the optical axis; the first telescopic camera (4) images the first portion of the parallel reflected light beam to obtain a target surface image of the single-photon detector (1); and the aspheric focusing lens (2) is adjusted so that the single-photon detector (1) The target surface is imaged clearly on the first telescopic camera (4), and the aspheric focusing lens (2) is used to calibrate the focus of the target surface of the single-photon detector (1); the single-photon detector (1) is adjusted so that the target surface of the single-photon detector (1) is located at the center of the imaging area of ​​the first telescopic camera (4), and the optical axis calibration of the target surface of the single-photon detector and the aspheric focusing lens (2) is achieved; the parallel light beam of the parallel light source is reflected and split by the first beam splitter (3) to obtain a first part of the parallel light beam, which arrives at the second telescopic camera (5) along the vertical optical axis to form a parallel light image point, and the parallel light image point is used as a calibration point for the optical axis calibration and focus calibration of the target surface of the single-photon detector (1) and the aspheric focusing lens (2); In the compensation mode, the first telescopic camera (4), the second beam splitter (6) and the parallel light source (8) are removed, and the telescope system (9) is connected as the parallel light source; the telescope system (9) tracks the star image of the second telescopic camera (5) and uses the image point as the calibration point for the optical axis calibration and focus calibration of the single-photon detector (1) target surface and the aspheric focusing lens (2); after the optical system of the telescope system is affected by environmental or human factors, the star image monitored by the second telescopic camera (5) will be deteriorated, that is, the spot of the single-photon detector (1) focused by the aspheric focusing lens (2) will be deteriorated. At this time, by adjusting the concave lens (71) and the convex lens (72) in the collimating compensation lens group (7), the number of pixels occupied by the star image in the second telescopic camera (5) is minimized, thereby achieving real-time monitoring and compensation of the high-precision spatial coupling of the single-photon detector connected to the telescope system (9).

2. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1 is characterized in that: The single-photon detector (1) can be adjusted forward and backward, up and down, left and right, and in pitch, and is used for alignment adjustment of the optical axis. It has a locking function and can be stably locked after adjustment. The aspheric focusing lens (2) can be adjusted forward and backward and can be locked after adjustment.

3. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 2 is characterized in that: The single-photon detector has an adjustment range of 2 to 5 mm up, down, left, and right, a pitch adjustment range of 0 to 10°, and a front and back adjustment range of 2 to 10 mm.

4. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1 is characterized in that: The reflectivity of the first beam splitter (3) to the parallel light beam of the parallel light source is 1% to 3%, and the transmittance is greater than or equal to 95%.

5. The spatial coupling and real-time monitoring compensation device based on single-photon detector according to claim 1 is characterized in that: The reflectivity of the second beam splitter (6) for the parallel light beam of the parallel light source is 50%, and the transmittance is 50%.

6. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1 is characterized in that: The quotient of the focal length of the convex lens (72) divided by the focal length of the concave lens (71) is greater than or equal to the quotient of the size of the beam of light irradiated onto the convex lens by the parallel light source or the telescope system and the clear aperture of the aspheric focusing lens.

7. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 6 is characterized in that: The quotient of the focal length of the convex lens divided by the focal length of the concave lens is 2 to 10; the quotient of the size of the beam of the parallel light source or the telescope system irradiating the convex lens and the aperture of the aspheric focusing lens is 1.1 to 1.5 times.

8. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1 is characterized in that: The spot size of the parallel light beam is 10 to 100 mm.

9. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1, characterized in that: The first telescopic camera (4) comprises a first focusing lens (41) and a first camera (42); the resolution of the first telescopic camera (4) is the pixel size of the first camera (42) divided by the focal length of the first focusing lens (41); the second telescopic camera (5) comprises a second focusing lens (51) and a second camera (52); the resolution of the second telescopic camera (5) is the pixel size of the second camera (52) divided by the focal length of the second focusing lens (51).

10. A method for spatial coupling and real-time monitoring compensation based on a single-photon detector according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: After the parallel light source emits a parallel light beam and passes through the collimating compensation lens group, the parallel light beam passes through the second beam splitter, the first beam splitter, and the aspheric focusing lens to the target surface of the single-photon detector. The single-photon detector reflects the parallel light beam to the second beam splitter, and part of the light is received by the first telescopic camera. The first telescopic camera images the target surface of the single-photon detector. The aspheric focusing lens is adjusted so that the target surface of the single-photon detector is clearly imaged in the first telescopic camera, thereby realizing the focus calibration of the aspheric focusing lens on the target surface of the single-photon detector. The single-photon detector is adjusted so that the target surface of the single-photon detector is centered in the imaging area of ​​the first telescopic camera, so as to achieve optical axis calibration between the target surface of the single-photon detector and the aspherical focusing lens; The first beam splitter reflects part of the light of the parallel light beam to the second telescopic camera to form an image point, and the image point is used as a calibration point for the optical axis calibration and focus calibration of the single-photon detector target surface and the aspheric focusing lens; When the received parallel light beam diverges or the light beam deviates, the image point formed by the second telescopic camera becomes larger or deviates from the calibration point, and compensation is achieved by adjusting the collimation compensation lens group.

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