Pixel multiplexing single-photon imaging system based on array laser

Abstract

The invention relates to a pixel multiplexing single-photon imaging system based on an array laser, which belongs to the technical field of photoelectric detection, and comprises an array laser, a lens, a single-photon detector and an electronics control subsystem, and the electronics control subsystem is electrically connected with the array laser and the single-photon detector. The electronic control subsystem is used for controlling each laser emitting unit in the array laser to sequentially emit pulse laser according to a preset sequence and a preset time period, each pixel in the single-photon detector receives photons reflected by each position of a detection target according to a certain time sequence, and the pulse laser is emitted by the single-photon detector in a pixel multiplexing mode. The method comprises the following steps: carrying out accumulative counting on photons detected in each time period, and arranging corresponding photon counting data and the spatial position of a corresponding detection target according to the spatial position of a laser emission unit to obtain a clear two-dimensional photon counting image of the detection target. According to the invention, the problem that target single-photon imaging of an existing single-photon detector is fuzzy is solved.

Description

Technical Field

[0001] The invention relates to the field of photoelectric detection technology, and in particular to a pixel multiplexing single-photon imaging system based on array lasers. Background Art

[0002] Single-photon detection technology is an active detection technology with ultra-high sensitivity: a laser pulse is emitted to the target. As long as one photon reflected by the target is detected and the flight time of this photon is calculated, the distance to the target point can be completed. If the target is scanned for distance measurement, or an array single-photon detector is used, the surface imaging of the target can be achieved. Usually, the laser is diffusely reflected on the surface of a non-cooperative target instead of being reflected by a mirror. The directionality of its echo photons is uncertain. A large number of diffusely reflected photons are not reflected back to the detector along the optical path of mirror reflection, but diffusely reflected in all directions within an angle range. When the non-cooperative target is farther away, the angle range containing these diffusely reflected photons is larger. The direct consequence of the above situation is that each pixel of the array single-photon detector may detect the photons diffusely reflected from each position of the non-cooperative target; or, the photons diffusely reflected from each position of the non-cooperative target may be detected by all pixels of the array single-photon detector. The above situation will cause blurry single-photon imaging of non-cooperative targets. Summary of the invention

[0003] In order to solve the problem that during the single-photon detection process, the photons reflected from the target may enter all pixels of the area array detector or the linear array detector and be recognized and detected by all pixels, resulting in blurred single-photon imaging of the target, the present invention proposes a pixel multiplexing single-photon imaging system based on array lasers.

[0004] To solve the above problems, the present invention adopts the following technical solutions:

[0005] A pixel multiplexing single-photon imaging system based on array lasers, comprising an array laser, a lens, a single-photon detector and an electronics control subsystem, wherein the electronics control subsystem is electrically connected to the array laser and the single-photon detector respectively;

[0006] The electronic control subsystem controls each laser emitting unit in the array laser to emit pulsed lasers in sequence according to a preset sequence and time period. After each emitted pulsed laser is reflected by the detection target, the reflected photons pass through the lens and are incident on the single-photon detector; the electronic control subsystem records the time sequence of photon events detected by each pixel of the single-photon detector in each time period and performs cumulative photon counting to obtain photon counting data corresponding to each laser emitting unit, wherein the photon events include detector photon counts caused by system noise photons, environmental noise photons, and echo signal photons; the electronic control subsystem arranges the photon counting data obtained according to the spatial position of each laser emitting unit in the array laser in accordance with the spatial position of the detection target to obtain a two-dimensional photon counting image of the detection target.

[0007] The beneficial effects of the present invention are:

[0008] The present invention controls each laser emitting unit in the array laser through an electronic control subsystem, and sequentially emits pulsed lasers according to a pre-set sequence and time period. Each pixel in the single-photon detector receives photons reflected from various positions of the detection target according to a certain time sequence. According to the time sequence of the echo signal photons detected by the single-photon detector, it can be determined which laser emitting unit in the array laser emitted the echo signal photons. Since one detector pixel in the present invention corresponds to not only one target position, but all positions of the detection target, it is a kind of pixel multiplexing. The electronic control subsystem accumulates and counts the photons detected by each pixel of the single-photon detector in each time period. At the same time, since the spatial position of the array laser and the detection target is one-to-one corresponding, the corresponding photon counting data is arranged according to the spatial position of each laser emitting unit in the array laser, corresponding to the spatial position of the detection target, and a two-dimensional photon counting image of the detection target can be obtained, and finally a clear reconstruction of the target image is completed, effectively solving the problem of blurred single-photon imaging of the target. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by the present invention.

[0010] Figure 1 This is a schematic diagram of a pixel multiplexing single-photon imaging system based on array lasers according to an embodiment of the present invention;

[0011] Figure 2Schematic diagram of the corresponding relationship between the array laser and the detection target position.

[0012] Explanation of the reference numerals: 101, array laser; 1011, first laser emitting unit; 1012, second laser emitting unit; 102, detection target; 1021, first target position; 1022, second target position; 103, lens; 104, single photon detector; 1041, pixel; 105, electronic control subsystem. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0014] like Figure 1 As shown, this embodiment provides a pixel multiplexing single-photon imaging system based on array laser, which includes an array laser 101, a lens 103, a single-photon detector 104 and an electronic control subsystem 105, wherein the electronic control subsystem 105 is electrically connected to the array laser 101 and the single-photon detector 104 respectively.

[0015] The array laser 101 includes a plurality of laser emitting units, each of which can emit pulsed lasers independently of one another, and the pulsed laser emission time can be precisely controlled under the control of the electronic control subsystem 105 .

[0016] According to an embodiment of the present invention, the array laser 101 may be any one of a VCSEL array laser, a stacked array laser, an array fiber laser, and a diffraction array output laser, or any combination of several of them.

[0017] According to an embodiment of the present invention, the single-photon detector 104 may be any one of a single-pixel single-photon detector, a linear array single-photon detector, and a planar array single-photon detector, or any combination of several of them. Figure 1 and Figure 2 The single-photon detector 104 is only taken as a planar array single-photon detector including a plurality of pixels 1041 for illustration, but it is not intended to limit the single-photon detector 104 .

[0018] The electronic control subsystem 105 includes a laser emission controller, a single photon counter, and a two-dimensional photon counting image reconstruction system, which are electrically connected to each other.

[0019] The laser emission controller in the electronic control subsystem 105 can control the moment, pulse width, pulse energy and laser wavelength of each laser emission unit in the array laser 101 to emit laser pulses. At the same time, the single photon counter in the electronic control subsystem 105 can record the time sequence of photon events detected by each pixel 1041 in the single photon detector 104, and perform corresponding photon accumulation counting. The two-dimensional photon counting image reconstruction system in the electronic control subsystem 105 can calculate the photon flight time, and statistically output the distance of the detection target 102, and arrange the spatial positions of the corresponding array laser 101 and the detection target 102, and finally obtain a two-dimensional photon counting image. The detection target 102 in this embodiment is a non-cooperative target or a cooperative target. The laser emission controller, single photon counter, and two-dimensional photon counting image reconstruction system included in the electronic control subsystem 105 in this embodiment can all be implemented using existing controllers, counters, and image reconstruction systems, which will not be repeated here.

[0020] Specifically, the laser emission controller included in the electronic control subsystem 105 first sets and records the moment, pulse width, pulse energy and laser wavelength of the laser emission unit in the array laser 101 emitting the laser pulse. After the setting is completed, each laser emission unit in the array laser 101 is numbered. The laser emission controller controls each laser emission unit in the array laser 101 to emit pulse lasers in sequence according to a preset order (or number) and time period (or timing). After each emitted pulse laser is reflected by the detection target 102, the reflected photon passes through the lens 103 and is incident on the single photon detector 104, and is detected by the pixel 1041 in the single photon detector 104.

[0021] In each time period when the laser emitting unit emits pulsed laser, the single photon counter included in the electronic control subsystem 105 records the time sequence of photon events detected by each pixel 1041 of the single photon detector 104 in the time period, and performs cumulative photon counting of all pixels 1041 in the time period. In each time period, the photon events detected by all pixels 1041 included in the single photon detector 104 are assumed to be photons reflected from the corresponding position of the target corresponding to a laser emitting unit in the array laser 101. According to the time sequence of the echo signal photons detected by the single photon detector 104, it can be determined which laser emitting unit in the array laser 101 emitted the echo signal photons. After all laser emitting units have completed emitting pulsed lasers, the photon counting data corresponding to each laser emitting unit is obtained. The photon events in this embodiment include detector photon counts caused by system noise photons, environmental noise photons, and echo signal photons.

[0022] Finally, since the spatial positions of the array laser 101 and the detection target 102 are one-to-one corresponding, the two-dimensional photon counting image reconstruction system contained in the electronic control subsystem 105 arranges the obtained photon counting data at the corresponding positions of the detection target 102 according to the spatial positions of each laser emitting unit in the array laser 101, and finally obtains a two-dimensional photon counting image of the detection target 102.

[0023] To further illustrate the acquisition of a two-dimensional photon counting image, the single-photon detector 104 is taken as an example as a surface array single-photon detector. Figure 2 As shown, during the time period when the first laser emitting unit 1011 emits a pulsed laser, the photon events detected by all the pixels 1041 included in the single-photon detector 104 are all considered to be the photon counting data of the first target position 1021 in the detection target 102. During the time period when the second laser emitting unit 1012 emits a pulsed laser, the photon events detected by all the pixels 1041 included in the single-photon detector 104 are all considered to be the photon counting data of the second target position 1022 in the detection target 102, and so on. After collecting the photon counting data of all corresponding positions of the detection target 102, the photon counting data of the corresponding positions of the detection target 102 are arranged correspondingly according to the spatial positions of the laser emitting units in the array laser 101, and a two-dimensional photon counting image of the detection target 102 can be obtained.

[0024] The present invention controls each laser emitting unit in the array laser through an electronic control subsystem, and sequentially emits pulsed lasers according to a pre-set sequence and time period. Each pixel in the single-photon detector receives photons reflected from various positions of the detection target according to a certain time sequence. According to the time sequence of the echo signal photons detected by the single-photon detector, it can be determined which laser emitting unit in the array laser emitted the echo signal photons. Since one detector pixel in the present invention corresponds not only to one target position, but to all positions of the detection target, it is a kind of pixel multiplexing. The electronic control subsystem accumulates and counts the photons detected by each pixel of the single-photon detector in each time period. At the same time, since the spatial positions of the array laser and the detection target are one-to-one corresponding, the corresponding photon counting data is arranged according to the spatial positions of each laser emitting unit in the array laser to correspond to the spatial position of the detection target, so that a two-dimensional photon counting image of the detection target can be obtained, and finally a clear reconstruction of the target image is completed, effectively solving the problem of blurred single-photon imaging of the target.

[0025] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0026] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A pixel multiplexing single-photon imaging system based on array laser, characterized in that: It comprises an array laser (101), a lens (103), a single photon detector (104) and an electronic control subsystem (105), wherein the electronic control subsystem (105) is electrically connected to the array laser (101) and the single photon detector (104) respectively; The electronic control subsystem (105) controls each laser emitting unit in the array laser (101) to emit pulsed lasers in sequence according to a preset sequence and time period. After each emitted pulsed laser is reflected by the detection target (102), the reflected photons pass through the lens (103) and are incident on the single photon detector (104). The electronic control subsystem (105) records the time sequence of photon events detected by each pixel (1041) of the single photon detector (104) in each time period and performs cumulative photon counting to obtain photon counting data corresponding to each laser emitting unit. The photon events include detector photon counts caused by system noise photons, environmental noise photons, and echo signal photons. The electronic control subsystem (105) arranges the photon counting data obtained corresponding to the spatial positions of the laser emitting units in the array laser (101) in accordance with the spatial positions of the detection target (102) to obtain a two-dimensional photon counting image of the detection target (102).

2. The pixel multiplexing single-photon imaging system based on array laser according to claim 1, characterized in that: The array laser (101) is any one of a VCSEL array laser, a stacked array laser, an array fiber laser, and a diffraction array output laser, or a combination of any of the above.

3. The pixel multiplexing single-photon imaging system based on array laser according to claim 1, characterized in that: The single-photon detector (104) is any one of a single-pixel single-photon detector, a linear array single-photon detector, and a surface array single-photon detector, or a combination of any of the above.

4. The pixel multiplexing single-photon imaging system based on array laser according to claim 1, characterized in that: The electronics control subsystem (105) includes a laser emission controller, a single photon counter and a two-dimensional photon counting image reconstruction system.

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