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

Abstract

The present invention discloses a spatial 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 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); in a calibration mode, the aspheric focusing lens is used to calibrate the focus and optical axis of the single-photon detector target surface; the first beam splitter forms an image point after reflecting the parallel light beam to the second telescopic camera, and the image point serves as a calibration point for the focus calibration between the single-photon detector target surface and the optical axis of the aspheric focusing lens; when the received parallel light beam diverges or the beam deflects, compensation is achieved by adjusting the collimating compensation lens group. The present invention ensures stable photon receiving efficiency of the laser ranging system through real-time monitoring and compensation.

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 space exploration and space technology, human activities in space have continued to intensify, but this has also generated an increasing amount of space debris. Space debris refers to all man-made objects in orbit other than functioning spacecraft. This includes completed rocket bodies and satellite bodies, rocket ejecta, discarded objects during space missions, and debris resulting from collisions between space objects. It is also known as "space junk." Currently, there are hundreds of millions of pieces of space debris larger than millimeters in size, totaling thousands of tons. Tens of thousands of spacecraft have been launched worldwide and could crash into Earth at any time. Space debris larger than centimeters can completely damage a spacecraft, while the cumulative impact of millimeter- or micron-sized debris can lead to performance degradation or even failure. The existence of space debris poses a serious threat to the safety of spacecraft in orbit, and the continued generation of space debris poses a significant threat to limited orbital resources.

[0003] Single-photon detectors are highly sensitive and can respond to single photons, making them ideal for receiving weak light signals. They are often used as laser echo receivers to detect laser echoes reflected from distant satellites / space debris. Laser ranging based on single-photon detectors offers the advantages of long-range measurement and high accuracy, making them a common method for high-precision orbit determination of space debris and enabling improved satellite / space debris orbit monitoring. Laser ranging systems require that the laser beam be able to accurately target space debris. The space debris will reflect the emitted laser back to the ground, where it will be received by the laser ranging system's receiving telescope and ultimately detected by the laser ranging system's single-photon detector, which will output an echo signal, achieving laser ranging.

[0004] Because space debris is very far from the Earth's surface and moves very quickly, it is difficult to both target and capture laser light reflected from space debris. Furthermore, since the detection target surface of a single-photon detector is generally small (~100 μm), it is difficult for the laser echo coupled by the ranging telescope system to enter the single-photon detector target surface. Furthermore, the telescope system is affected by environmental and human factors, and the mechanical structure and optical path of the telescope system are subject to frequent micro-changes. This can cause the laser echo coupled into the single-photon detector to deviate significantly, significantly reducing the single-photon detector's receiving efficiency, and even deviating from the single-photon detector target surface, preventing effective detection.

[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 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.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] 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 telephoto camera 4, a second telephoto 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 includes a concave lens 71 and a convex lens 72;

[0009] In the calibration mode, the parallel light source 8 emits a parallel light beam, which 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; by adjusting the aspheric focusing lens 2, the target surface of the single-photon detector 1 is aligned with the target surface image 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 located 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 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;

[0010] In compensation mode, the first telephoto camera 4, the second beam splitter 6, and the parallel light source 8 are removed, and a telescope system 9 is connected as a parallel light source. The telescope system 9 tracks the star image, and the imaging point of the second telephoto camera 5 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. When the optical system of the telescope system 9 is affected by environmental or human factors, the star image monitored by the second telephoto camera 5 will be deteriorated, that is, the aspheric focusing lens 2 will focus the parallel light on the light spot of the single-photon detector 1, and the concave lens 71 and the convex lens 72 in the collimating and compensating lens group 7 are adjusted to minimize the number of pixels occupied by the star image in the second telephoto camera 5, thereby achieving real-time monitoring and compensation of high-precision spatial coupling of the single-photon detector connected to the telescope system 9.

[0011] 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 pitch and roll for optical axis alignment adjustment. 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.

[0012] According to one embodiment of the present invention, the single-photon detector has an adjustment range of 2 to 5 mm in up and 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.

[0013] According to one 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%.

[0014] According to one 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%.

[0015] 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 beam size of the parallel light source or telescope system irradiating the convex lens and the clear aperture of the aspheric focusing lens.

[0016] 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 telescope system irradiated onto the convex lens and the clear aperture of the aspheric focusing lens is 1.1 to 1.5 times.

[0017] According to one embodiment of the present invention, the spot size of the parallel light beam is 10 to 100 mm.

[0018] 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.

[0019] 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:

[0020] 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 by the first telescopic camera, thereby achieving focus calibration of the aspheric focusing lens on the target surface of the single-photon detector.

[0021] Adjusting the single-photon detector so that the single-photon detector target surface is centered in the imaging area of the first telescopic camera, thereby achieving optical axis calibration between the single-photon detector target surface and the aspheric focusing lens;

[0022] The first beam splitter reflects part of the parallel light beam to the second telescopic camera to form an image point, and the image point serves as a calibration point for the optical axis calibration and focus calibration of the single-photon detector target surface and the aspheric focusing lens;

[0023] When the incoming parallel light beam diverges or the beam shifts, the image point formed by the second telescopic camera becomes larger or shifts the calibration point, and compensation is achieved by adjusting the collimating compensation lens group.

[0024] The present invention provides a spatial coupling and real-time monitoring compensation device and method based on a single-photon detector. The device monitors the optical axis and focus of an aspheric focusing lens focusing parallel light onto a single-photon detector through a long-range camera, and monitors the optical deviation of an connected telescope system in real time. The device also performs real-time compensation by adjusting a collimating compensation lens group.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 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.

[0027] 2. Use a second telescopic camera and collimating compensating lens group to monitor in real time the parallel light entering distant stars through the telescope system. When changes in the star image emission of the telescope system are monitored, the collimating compensating lens group is adjusted to compensate for slight changes in the telescope system.

[0028] 3. Use beam splitters to form multiple light paths and achieve equivalent constant light paths for each light path. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying 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 accompanying drawings:

[0030] 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.

[0031] Figure 2 1 is an optical path diagram of a compensation device based on spatial coupling and real-time monitoring of a single-photon detector in a compensation mode according to an exemplary embodiment of the present invention.

[0032] Reference numerals:

[0033] 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 and compensating lens group; 71-concave lens; 72-convex lens; 8-parallel light source; 9-telescope system; 91-condenser; 92-collimator; 93-reflector. DETAILED DESCRIPTION

[0034] To facilitate a clear description of the technical solutions of the embodiments of the present invention, the words "first" and "second" are used in the embodiments of the present invention to distinguish between identical or similar items with substantially the same functions and effects. For example, the first threshold and the second threshold are merely used to distinguish between different thresholds and do not limit their order. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0035] 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 construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0036] In the present invention, "at least one" means one or more, and "more" 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: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. The following at least one item (item) or similar expressions refers to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one item (item) 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 plural.

[0037] A spatial coupling and real-time monitoring compensation device based on a single-photon detector according to an embodiment of the present invention includes: 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.

[0038] 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 and compensating lens group 7 includes a concave lens 71 and a convex lens 72 .

[0039] 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;

[0040] After the parallel light beam is reflected by the target surface of the single-photon detector 1, a parallel reflected light beam is obtained. 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 portion of parallel reflected light beams perpendicular to the optical axis. The first portion of the parallel reflected light beam reaches the first telescopic camera 4, which images the target surface of the single-photon detector 1.

[0041] 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 made clear, thereby achieving focus calibration of the aspheric focusing lens 2 on the target surface of the single-photon detector 1;

[0042] The optical axis of the single-photon detector 1 and the aspheric focusing lens 2 are calibrated 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;

[0043] 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 an image of a parallel light point. The parallel light point serves 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.

[0044] The single-photon detector 1 can be adjusted forward, backward, vertically, horizontally, and in pitch, for alignment with the horizontal optical axis. It also features a locking function, ensuring a stable lock after adjustment to prevent loosening. The single-photon detector can be adjusted vertically, horizontally, and horizontally within a range of 2 to 5 mm, with a pitch adjustment range of 0 to 10°, and a forward and backward adjustment range of 2 to 10 mm.

[0045] 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.

[0046] 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 directed to the single-photon detector 1, and a small part is directed to the second telescopic camera 5 for imaging.

[0047] 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.

[0048] like Figure 2 As shown, the device is in compensation mode, removing Figure 1 The first telescopic camera 4, second beam splitter 6, and parallel light source 8 are connected to a telescope system 9. The telescope system 9 serves as a parallel light source. Telescope system 9 tracks stars. The parallel light beams represent the star's image (stellar parallel light imaging). The image point of the star's image on the second telescopic camera 5 serves as a calibration point for optical axis alignment and focus calibration between the target surface of the single-photon detector 1 and the aspheric focusing lens 2.

[0049] exist Figure 2In the figure, an exemplary telescope system is given, which includes a condenser 91, a collimator 92, and a reflector 93. The star image is condensed by the condenser 91 and collimated by the collimator 92 to obtain star image parallel light. The reflector 93 reflects the star 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.

[0050] When the optical system of telescope system 9 is affected by environmental or human factors, the image of the stars monitored by the second telescopic camera 5 will deteriorate. That is, the spot of the parallel light focused by the aspheric focusing lens 2 on the single-photon detector 1 will be deteriorated. At this time, by adjusting the concave lens 71 and convex lens 72 in the collimating and compensating lens group 7, the star image in the second telescopic camera 5 is optimally imaged with the minimum number of pixels occupied, thereby achieving high-precision real-time monitoring and compensation of the spatial coupling of the single-photon detector connected to the telescope system 9.

[0051] 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 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 size of the 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.

[0052] When the device is in calibration mode or compensation mode, when the parallel light source 8 or the parallel light beam of the telescope system 9 connected thereto diverges or deviates, the image point formed by the second telescopic camera 5 becomes larger or deviates from the calibration point, and the collimating and compensating lens group 7 is adjusted to make the parallel light image point meet the requirements as the calibration point.

[0053] 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.

[0054] Existing coupling technologies for single-photon detectors can only achieve spatial coupling, connecting photons in free space to single-photon detectors. In particular, in laser detection, photons of laser echo signals are coupled into single-photon detectors 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 and compensation device for single-photon detectors of the present invention provides a better spatial coupling method for photon reception of single-photon detectors, and can perform real-time monitoring and compensation. By monitoring the quality of the imaging points of the parallel light incident on the single-photon detector, it is possible to promptly detect whether the telescope system has deviated. After the deviation occurs, the concave lens 71 and the convex lens 72 in the collimating 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.

[0055] A spatial coupling and real-time monitoring compensation method based on a single-photon detector comprises the following steps:

[0056] 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 by the first telescopic camera, thereby achieving focus calibration of the aspheric focusing lens on the target surface of the single-photon detector.

[0057] 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, thereby achieving optical axis calibration between the target surface of the single-photon detector and the aspheric focusing lens; the first beam splitter reflects a portion of the parallel light beam to the second telescopic camera to form an image point, and the image point serves as a calibration point for focus calibration between the target surface of the single-photon detector and the optical axis of the aspheric focusing lens;

[0058] When the incoming parallel light beam diverges or the beam shifts, the image point formed by the second telescopic camera becomes larger or shifts the calibration point, and compensation is achieved by adjusting the collimating compensation lens group.

[0059] In 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 incoming parallel light beam spot. For example, 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.

[0060] The existing single telescopic camera lacks a second telescopic camera when connected to the working optical path, so it lacks monitoring of the working optical path. At the same time, due to the lack of a collimating compensation lens group, the working optical path lacks compensation function due to environmental or human factors during testing.

[0061] 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 optical path only uses one telescopic camera to monitor the working optical path. When the working optical 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 optical path is monitored by the camera monitoring the parallel light beam, and the monitoring situation of the working optical path and the effect of the parallel light beam monitoring are analyzed to determine whether there is a problem with the working optical path. If there is a problem, the collimation compensation mirror group is adjusted to ensure that the working optical path and the parallel optical path adjusted by calibration have good consistency, thereby ensuring that the working optical path can be well coupled into the single-photon detector.

[0062] The image point formed on the second telescopic camera of the working optical path 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, the collimator compensation mirror is required to be coarsely adjusted over a large range to reduce the image point to less than or equal to the first deviation threshold. If it is still greater than the second deviation threshold after being reduced, fine adjustment is performed over a small range to ensure that the image point is smaller than the target threshold size. The smaller the image point size after collimator compensation, the better. If the deviation between the image point size after collimator compensation and the calibrated image point size is not large, for example, greater than the second deviation threshold, the collimator compensation mirror is fine-tuned to ensure that the image point is smaller than the target threshold size. The smaller the better.

[0063] 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.

[0064] 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 reviewing the drawings, the disclosure, and the drawings, etc. In the specification, the word "comprising" does not exclude other components or steps, and "a" 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.

[0065] Although the present invention has been described with reference to specific features and embodiments thereof, it will be apparent that various modifications and combinations thereof may be made without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the present invention and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the invention. It will be apparent that various modifications and variations of the present invention may be made by those skilled in the art without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such modifications and variations as fall within the scope of the 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) includes 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 convex lens (72) and the concave lens (71) of the collimating compensation mirror group (7) configured along the horizontal common optical axis, the second beam splitter (6), the first beam splitter (3), and the aspheric focusing lens (2). The parallel reflected light beam obtained after being reflected 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); by adjusting the aspheric focusing lens (2) The image of the target surface of the single-photon detector (1) on the first telescopic camera (4) is made clear, and the focus calibration of the aspheric focusing lens (2) on the target surface of the single-photon detector (1) is achieved; 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 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 star at the second telescopic camera (5) and uses the imaging 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 parallel light focused by the aspheric focusing lens (2) on 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 number of pixels occupied by the star image in the second telescopic camera (5) is minimized, thereby realizing 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 single-photon detector according to claim 2, characterized in that: The single-photon detector has an adjustment range of 2 to 5 mm up and 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, 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, characterized in that: 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%.

6. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1, 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, 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 beam size 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.

8. The spatial coupling and real-time monitoring compensation device based on a single-photon detector according to claim 1, 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 by the first telescopic camera, thereby achieving focus calibration of the aspheric focusing lens on the target surface of the single-photon detector. Adjusting the single-photon detector so that the single-photon detector target surface is centered in the imaging area of the first telescopic camera, thereby achieving optical axis calibration between the single-photon detector target surface and the aspheric focusing lens; The first beam splitter reflects part of the parallel light beam to the second telescopic camera to form an image point, and the image point serves 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 incoming parallel light beam diverges or the beam shifts, the image point formed by the second telescopic camera becomes larger or shifts the calibration point, and compensation is achieved by adjusting the collimating compensation lens group.

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