Method for Post-Pulse Correction of Response Curve of Single-Photon Indium Gallium Arsenide Detector

Abstract

The present application discloses a method for afterpulse correction based on the response curve of a single-photon indium gallium arsenide detector. According to the photon counts detected by the single-photon indium gallium arsenide detector to be corrected under different input signals, and the corresponding relationship between the photon counts detected by the detector to be corrected and its afterpulse correction curve obtained in advance, the afterpulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals is obtained, so as to perform afterpulse correction on the response curve of the detector to be corrected under the corresponding photon count detection situation. Compared with the prior art method of using the afterpulse correction curve of the detector to be corrected under a single photon count situation to perform afterpulse correction on the response curves of the detector to be corrected under different photon count detection situations, this method makes the response curve of the detector after afterpulse correction more accurate, thereby improving the stability and reliability of lidar detection data.

Description

Technical Field

[0001] The present application relates to the technical field of lidar, and particularly to a method for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector. Background Art

[0002] Lidar, especially infrared lidar in the range of 1μm - 1.5μm, has become a hot research field in laser remote sensing due to its advantages such as mature laser technology, small size, invisibility of infrared light, eye safety, and easy integration. In existing infrared lidars, quantum up-conversion detectors, superconducting nanowire detectors, and single-photon detectors (SPADs) are mainly used to detect the echo signals of lidars. Among them, single-photon detectors can detect weak optical signals because of their ultra-low noise and enhanced sensitivity. The incident light intensity can be as low as the single-photon level, so they are valued by various lidar manufacturers.

[0003] The core device of a single-photon detector is a single-photon avalanche photodiode based on indium gallium arsenide material. Due to the uncertainty of the target position in lidar, the arrival time of signal photons is random. Therefore, the single-photon indium gallium arsenide detector used in lidar usually operates in a free-running linear mode, and its reverse bias is always in the avalanche breakdown range. Specifically, electrons and holes excited by signal photons in the absorption layer of the single-photon indium gallium arsenide detector flow to the anode and cathode respectively under the action of an electric field, forming a photocurrent. The magnitude of the photocurrent is proportional to the incident light intensity. Among them, the excited electrons enter the multiplication layer of the single-photon indium gallium arsenide detector, are accelerated by a strong electric field to obtain sufficient energy, collide to generate additional free electrons, forming an avalanche effect. Subsequently, through a passive quenching circuit, the avalanche current is quenched to end the detection of a single signal photon, and the corresponding response curve is obtained.

[0004] However, after a large number of free electrons and holes in the single-photon indium gallium arsenide detector recombine, there are still a small number of free electrons that survive. These surviving free electrons have a certain probability of triggering an avalanche effect again, forming post-pulse counts, resulting in inaccurate response curves of the single-photon indium gallium arsenide detector. The magnitude of the post-pulse probability is one of the important indicators for measuring the performance of a single-photon indium gallium arsenide detector. Especially in a lidar system, the post-pulse effect of the single-photon indium gallium arsenide detector will cause distortion of the lidar detection signal, affecting the stability and reliability of lidar detection data. Therefore, how to correct the response curve of the single-photon indium gallium arsenide detector for post-pulses has become a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] To solve the above technical problems, an embodiment of the present application provides a method for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector to perform post-pulse correction on the response curve of the single-photon indium gallium arsenide detector, thereby improving the stability and reliability of lidar detection data.

[0006] To achieve the above object, an embodiment of the present application provides the following technical solutions:

[0007] A method for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector includes:

[0008] Based on different input signals, obtain the response curves of the detector to be corrected under different input signals;

[0009] Based on the response curves of the detector to be corrected under different input signals, obtain the photon counts detected by the detector to be corrected under different input signals;

[0010] Based on the photon counts detected by the detector to be corrected under different input signals and the corresponding relationship between the photon counts detected by the detector to be corrected and its post-pulse correction curve obtained in advance, obtain the post-pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals;

[0011] Based on the post-pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals, perform post-pulse correction on the response curves of the detector to be corrected under different input signals.

[0012] Optionally, the process of obtaining the corresponding relationship between the photon counts detected by the detector to be corrected and its post-pulse correction curve includes:

[0013] Use a laser to generate a continuous laser signal;

[0014] Use an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulse optical signals with different light intensities, and the light intensity of the time-domain narrow pulse optical signal represents the number of photons it contains;

[0015] Input the time-domain narrow pulse optical signals with different light intensities into the detector to be corrected for detection in sequence, and obtain the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities;

[0016] Based on the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities, obtain the photon counts detected by the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities;

[0017] Based on the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities and the calibrated response curve, obtain the post-pulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities;

[0018] Based on the after-pulse correction curve of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, and the detected photon counts, the corresponding relationship between the photon counts detected by the detector to be corrected and its after-pulse correction curve is obtained.

[0019] Optionally, modulating the continuous laser signal into time-domain narrow pulsed optical signals with different light intensities by using an electro-optic modulator includes:

[0020] Using a first controller to generate a control signal for time-domain narrow pulsed optical signals with different light intensities;

[0021] Using a waveform generator to generate a waveform modulation signal for time-domain narrow pulsed optical signals with different light intensities based on the control signal for time-domain narrow pulsed optical signals with different light intensities;

[0022] Using an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulsed optical signals with different light intensities based on the waveform modulation signal for time-domain narrow pulsed optical signals with different light intensities.

[0023] Optionally, sequentially inputting time-domain narrow pulsed optical signals with different light intensities into the detector to be corrected for detection, and obtaining the response curve of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities includes:

[0024] Sequentially inputting time-domain narrow pulsed optical signals with different light intensities into the detector to be corrected for detection, and obtaining the photocurrent signals of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities;

[0025] Inputting the photocurrent signals of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities into a multi-channel digital signal acquisition card, and after analog-to-digital conversion, obtaining the digital signals of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities;

[0026] Inputting the digital signals of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities into a second controller, and obtaining the response curve of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0027] Optionally, the process of obtaining the calibrated response curve of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities includes:

[0028] Use an optical fiber splitter to split the time-domain narrow pulse optical signal output by the electro-optic modulator into two beams. Among them, one beam of the time-domain narrow pulse optical signal is input into the detector to be corrected, so as to sequentially input the time-domain narrow pulse optical signals with different light intensities into the detector to be corrected for detection. The other beam of the time-domain narrow pulse optical signal is input into the superconducting nanowire detector, so as to sequentially input the time-domain narrow pulse optical signals with different light intensities into the superconducting nanowire detector for detection, and obtain the response curve of the superconducting nanowire detector under the time-domain narrow pulse optical signals with different light intensities, which is used as the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities;

[0029] Alternatively, under preset conditions, sequentially input time-domain narrow pulse optical signals with different light intensities into the detector to be corrected, and obtain the response curve output by the detector to be corrected according to the time-domain narrow pulse optical signals with different light intensities under the preset conditions, which is used as the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities.

[0030] Optionally, the process of obtaining the correspondence between the photon count detected by the detector to be corrected and its subsequent pulse correction curve further includes:

[0031] Make a data table of the correspondence between the photon count detected by the detector to be corrected and its subsequent pulse correction curve, and store it in the detector to be corrected.

[0032] Compared with the prior art, the above technical solution has the following advantages:

[0033] The post-pulse correction method for the response curve of a single-photon indium gallium arsenide detector provided by an embodiment of the present application includes: obtaining the response curve of the detector to be corrected under different input signals based on different input signals; obtaining the photon counts detected by the detector to be corrected under different input signals based on the response curve of the detector to be corrected under different input signals; obtaining the post-pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals based on the photon counts detected by the detector to be corrected under different input signals and the pre-obtained corresponding relationship between the photon counts detected by the detector to be corrected and its post-pulse correction curve; and performing post-pulse correction on the response curve of the detector to be corrected under different input signals based on the post-pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals. It can be seen that compared with the prior art method of using the post-pulse correction curve of the detector to be corrected under a single photon count to perform post-pulse correction on the response curve of the detector to be corrected under different detected photon counts, this method performs post-pulse correction on the response curve of the detector to be corrected under the corresponding detected photon counts according to the post-pulse correction curves of the detector to be corrected under different detected photon counts, that is, the response curves of the detector to be corrected under different detected photon counts correspond to different post-pulse correction curves, making the response curve of the detector after post-pulse correction more accurate, thereby improving the stability and reliability of the lidar detection data. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 Schematic diagram for comparison before and after post-pulse correction of the response curve of a single-photon indium gallium arsenide detector in a lidar system;

[0036] Figure 2 Schematic diagram of the relationship between the quantum efficiency and post-pulse probability of a certain type of single-photon indium gallium arsenide detector and the photon counts detected by it;

[0037] Figure 3 Flow chart of the post-pulse correction method for the response curve of a single-photon indium gallium arsenide detector provided by an embodiment of the present application;

[0038] Figure 4 For Figure 3In the shown process, it is a schematic diagram of a process for pre-obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve;

[0039] Figure 5 For Figure 4 In the shown process, it is a schematic diagram of a process for modulating a continuous laser signal into a time-domain narrow pulse optical signal with different light intensities by using an electro-optic modulator;

[0040] Figure 6 Based on Figure 4 And Figure 5 In the shown process, it is a schematic diagram of an implementation method for obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve;

[0041] Figure 7 For Figure 5 In the shown process, it is a schematic diagram of the correspondence between the light intensity of the time-domain narrow pulse optical signal with different light intensities modulated by using an electro-optic modulator and the range gate;

[0042] Figure 8 For Figure 4 In the shown process, it is a schematic diagram of a process for sequentially inputting time-domain narrow pulse optical signals with different light intensities into the detector to be corrected for detection, and obtaining the response curve of the detector to be corrected under time-domain narrow pulse optical signals with different light intensities;

[0043] Figure 9 Based on Figure 4 In the shown process, it is another schematic diagram of an implementation method for obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve;

[0044] Figure 10 Based on Figure 4 In the shown process, it is yet another schematic diagram of an implementation method for obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve;

[0045] Figure 11 For Figure 3 In the shown process, it is another schematic diagram of a process for pre-obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the protection scope of the present application.

[0047] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application may be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0048] Secondly, the present application will be described in detail in conjunction with schematic diagrams. When detailing the embodiments of the present application, for the sake of illustration, the cross-sectional views showing the device structure will be enlarged locally out of the general scale, and the schematic diagrams are only examples and should not limit the scope of protection of the present application herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0049] As described in the background art section, how to perform afterpulse correction on the response curve of a single-photon indium gallium arsenide detector has become a technical problem that those skilled in the art urgently need to solve.

[0050] The inventors have found through research that, on the one hand, by optimizing the performance of the single-photon indium gallium arsenide detector and reasonably selecting the detector parameters, the probability of its afterpulses can be minimized as much as possible; on the other hand, since the afterpulse probability follows a statistical distribution, therefore, a correction algorithm can be used to perform afterpulse correction on the response curve of the single-photon indium gallium arsenide detector. Figure 1 A comparison schematic diagram before and after performing afterpulse correction on the response curve of a single-photon indium gallium arsenide detector in a lidar system is given. Among them, the vertical axis is the photon number error, which represents the photon counting error caused by the afterpulse effect rather than the actual signal photons in the single-photon indium gallium arsenide detector, and the horizontal axis is the detection distance of the lidar. From Figure 1 it can be seen that as the detection distance of the lidar increases, the photon number error of the single-photon indium gallium arsenide detector becomes larger, that is, the afterpulse effect of the single-photon indium gallium arsenide detector is more obvious. After performing afterpulse correction on the response curve of the single-photon indium gallium arsenide detector, the photon number error is stabilized within a smaller range. Therefore, it is very necessary to perform afterpulse correction on the response curve of the single-photon indium gallium arsenide detector.

[0051] The inventors further found through research that in different weather conditions, the echo signal intensity of the lidar has a large dynamic range. For example, in cloudy and foggy weather, the photon counting rate range of the lidar echo signal is 0.1 KHz - 200 MHz, where the photon counting rate refers to the photon count received by the lidar per unit time, that is, the photon count received by the single-photon indium gallium arsenide detector per unit time. And, as Figure 2 shown, Figure 2 a schematic diagram showing the relationship between the quantum efficiency and the afterpulse probability of a certain model of single-photon indium gallium arsenide detector and the photon count detected by it is given. From Figure 2It can be seen that the more photons incident on the photosensitive surface of the single-photon indium gallium arsenide detector, that is, the more photon counts detected by the single-photon indium gallium arsenide detector, the greater the amount of charge flowing through the single-photon indium gallium arsenide detector during a single avalanche process. Then, the more electron-hole pairs remaining in the single-photon indium gallium arsenide detector, the greater the probability of triggering the afterpulse effect in the single-photon indium gallium arsenide detector, and the lower the quantum efficiency of the single-photon indium gallium arsenide detector.

[0052] Thus, it can be seen that in a lidar system, the intensity of the radar echo signal received by the single-photon indium gallium arsenide detector changes dynamically under the influence of the external environment, that is, the photon counts detected by the single-photon indium gallium arsenide detector change dynamically, and the afterpulse probability of the single-photon indium gallium arsenide detector increases with the increase in the photon counts it detects. However, in the current methods for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector using a correction algorithm, usually, the post-pulse correction curve of the detector to be corrected under a single photon count is used to correct the response curves of the detector to be corrected under different detected photon counts, that is, the response curves of the detector to be corrected under different detected photon counts all correspond to the same post-pulse correction curve. It can be seen that this correction method has a large error and cannot accurately perform post-pulse correction on the response curves of the single-photon indium gallium arsenide detector under radar echo signals in different weather or environments.

[0053] Based on the above research, an embodiment of the present application provides a method for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector, as Figure 3 shown, the method includes:

[0054] S1: Based on different input signals, obtain the response curves of the detector to be corrected under different input signals.

[0055] It should be noted that the detector to be corrected is the single-photon indium gallium arsenide detector to be corrected, and the response curve of the detector to be corrected is the corresponding relationship between the photon counts detected by the detector based on the input signal and the detection time or detection distance of the input signal. Specifically, in an embodiment of the present application, taking the single-photon indium gallium arsenide detector applied in a lidar system as an example, the input signal is the lidar echo signals at different range gates. Among them, the lidar echo signal is the optical signal reflected from the target after the lidar emits a detection signal (pulsed laser beam) to the target, and the range gate is the detection time or detection distance between the lidar emitting the detection signal to the target and receiving the echo signal reflected from the target. Then, the response curve of this single-photon indium gallium arsenide detector is the corresponding relationship between the photon counts detected by this single-photon indium gallium arsenide detector receiving the lidar echo signals at different range gates and the range gate.

[0056] It should also be noted that, as can be seen from the description of the working principle of the single-photon indium gallium arsenide detector in the background art section, when an input signal is incident on the photosensitive surface of the single-photon indium gallium arsenide detector, electron-hole pairs are excited. The excited electrons and holes flow to the anode and cathode respectively under the action of an electric field, forming a photocurrent. The magnitude of the photocurrent is proportional to the light intensity of the input signal, and the light intensity of the input signal represents the number of photons it contains. Therefore, the magnitude of the photocurrent output by the single-photon indium gallium arsenide detector represents the number of photons contained in the input signal, thereby realizing the detection of the input signal.

[0057] However, the photocurrent signal output by the single-photon indium gallium arsenide detector is an analog signal. To obtain the response curve of the single-photon indium gallium arsenide detector, it is necessary to quantize the photocurrent signal output by the single-photon indium gallium arsenide detector to form a digital signal, and then input the quantized digital signal into a computer to obtain the response curve of the single-photon indium gallium arsenide detector, so as to reflect the corresponding relationship between the photon count detected by the single-photon indium gallium arsenide detector based on the input signal and the detection time or detection distance of the input signal. In practical applications, a multi-channel digital signal acquisition card can be used to perform analog-to-digital conversion on the photocurrent signal output by the single-photon indium gallium arsenide detector. Among them, the multi-channel digital signal acquisition card can be embedded in the single-photon indium gallium arsenide detector or independent of the single-photon indium gallium arsenide detector.

[0058] S2: Based on the response curves of the detector to be corrected under different input signals, obtain the photon counts detected by the detector to be corrected under different input signals.

[0059] It should be noted that the input signal of the single-photon indium gallium arsenide detector is usually a time-domain narrow pulse optical signal. The photocurrent output by the single-photon indium gallium arsenide detector first gradually increases due to the avalanche effect and then is quenched by the quenching circuit. Therefore, the response curve of the single-photon indium gallium arsenide detector under the time-domain narrow pulse optical signal is also in the form of a narrow pulse, that is, it first increases, then decreases, and has a peak point in the middle.

[0060] Generally, the photon count corresponding to the peak point of the response curve of the single-photon indium gallium arsenide detector under the time-domain narrow pulse optical signal is used as the photon count detected by the single-photon indium gallium arsenide detector under the time-domain narrow pulse optical signal. However, this application does not make any limitations in this regard and depends on the specific situation. As long as the photon counts detected by the detector to be corrected under different input signals can be obtained from the response curves of the detector to be corrected under different input signals.

[0061] S3: Based on the photon counts detected by the detector to be corrected under different input signals and the corresponding relationship between the photon counts detected by the detector to be corrected and the afterpulse correction curve obtained in advance, obtain the afterpulse correction curves corresponding to the photon counts detected by the detector to be corrected under different input signals;

[0062] S4: Based on the afterpulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals, perform afterpulse correction on the response curve of the detector to be corrected under different input signals.

[0063] As known from the foregoing, the afterpulse probability of a single-photon indium gallium arsenide detector increases with the increase in the photon counts it detects. Therefore, the afterpulse correction curve of a single-photon indium gallium arsenide detector also needs to change according to the change in the photon counts it detects. It can be seen from steps S3 - S4 that, compared with the prior art, using the afterpulse correction curve of the detector to be corrected under a single photon count to perform afterpulse correction on the response curves of the detector to be corrected under different detected photon counts, that is, the response curves of the detector to be corrected under different detected photon counts all correspond to the same afterpulse correction curve. The afterpulse correction method for the response curve of the single-photon indium gallium arsenide detector provided in the embodiments of the present application performs afterpulse correction on the response curve of the detector to be corrected under the corresponding detected photon counts according to the afterpulse correction curves of the detector to be corrected under different detected photon counts, that is, the response curves of the detector to be corrected under different detected photon counts correspond to different afterpulse correction curves, solving the problem that the afterpulse correction curve of a single-photon indium gallium arsenide detector changes with the change in the photon counts it detects, making the response curve of the detector after afterpulse correction more accurate, and particularly can accurately perform afterpulse correction on the response curves of a single-photon indium gallium arsenide detector under radar echo signals in different weather or environments, thereby improving the stability and reliability of lidar detection data.

[0064] Based on the above embodiments, optionally, in an embodiment of the present application, as Figure 4 shown, the process of obtaining the correspondence between the photon counts detected by the detector to be corrected and its afterpulse correction curve includes:

[0065] S31: Use a laser to generate a continuous laser signal;

[0066] S32: Use an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulse optical signals with different light intensities, and the light intensity of the time-domain narrow pulse optical signal represents the number of photons it contains.

[0067] Optionally, in an embodiment of the present application, as Figure 5 shown, using an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulse optical signals with different light intensities includes:

[0068] S321: Use a first controller to generate control signals for time-domain narrow pulse optical signals with different light intensities;

[0069] S322: Using a waveform generator, based on the control signal of the time-domain narrow pulse optical signal with different light intensities, generate a waveform modulation signal of the time-domain narrow pulse optical signal with different light intensities;

[0070] S323: Using an electro-optic modulator, based on the waveform modulation signal of the time-domain narrow pulse optical signal with different light intensities, modulate the continuous laser signal into a time-domain narrow pulse optical signal with different light intensities.

[0071] Specifically, Figure 6 Figure 8 shows a schematic diagram of an implementation method for modulating the continuous laser signal emitted by a laser into a time-domain narrow pulse optical signal with different light intensities in this embodiment. It can be seen from Figure 6 It can be seen that:

[0072] The output end of the laser 10 is connected to the optical input end of the electro-optic modulator 20 to output the continuous laser signal generated by the laser 10 to the electro-optic modulator 20;

[0073] The output end of the first controller 30 is connected to the input end of the waveform generator 40 to use the first controller 30 to generate a control signal of the time-domain narrow pulse optical signal with different light intensities and output it to the waveform generator 40;

[0074] The output end of the waveform generator 40 is connected to the electrical input end of the electro-optic modulator 20 to use the waveform generator 40 to generate a waveform modulation signal of the time-domain narrow pulse optical signal with different light intensities based on the control signal of the time-domain narrow pulse optical signal with different light intensities and output it to the electro-optic modulator 20;

[0075] The electro-optic modulator 20 modulates the continuous laser signal emitted by the laser 10 into a time-domain narrow pulse optical signal with different light intensities based on the waveform modulation signal of the time-domain narrow pulse optical signal with different light intensities to simulate the time-domain narrow pulse optical signal received by the detector at different detection times or detection distances during the actual working process.

[0076] It should be noted that in actual applications, the first controller 30 generates only one control signal of the time-domain narrow pulse optical signal with a preset light intensity at a time and outputs it to the waveform generator 40; the waveform generator 40 generates a waveform modulation signal of the time-domain narrow pulse optical signal with the preset light intensity based on the control signal of the time-domain narrow pulse optical signal with the preset light intensity and outputs it to the electro-optic modulator 20; the electro-optic modulator 20 modulates the continuous laser signal emitted by the laser 10 into the time-domain narrow pulse optical signal with the preset light intensity based on the waveform modulation signal of the time-domain narrow pulse optical signal with the preset light intensity, and so on, to obtain time-domain narrow pulse optical signals with different preset light intensities.

[0077] In view of this, serial numbers can be marked on the time-domain narrow pulse optical signals with each preset optical intensity, so as to facilitate establishing a corresponding relationship between the photon count detected by the detector to be corrected and the subsequent pulse correction curve for the time-domain narrow pulse optical signals with the same serial number mark. Figure 7 The schematic diagram of the corresponding relationship between the optical intensity and the range gate of the time-domain narrow pulse optical signals with different optical intensities modulated from the continuous laser signal by using an electro-optic modulator is given. Among them, the vertical coordinate is the normalized optical intensity, the horizontal coordinate is the range gate, and the serial numbers of the time-domain narrow pulse optical signals at different range gates are the subsequent pulse correction sequence 1, the subsequent pulse correction sequence 2... the subsequent pulse correction sequence n. From Figure 7 It can be seen that as the range gate increases, the optical intensity of the modulated time-domain narrow pulse optical signal becomes smaller, which is consistent with the input signal of the single-photon indium gallium arsenide detector during actual operation.

[0078] It should also be noted that the optical intensity of the time-domain narrow pulse optical signal can cover the entire dynamic range of the input signal intensity that can be detected by the single-photon indium gallium arsenide detector, or only cover the dynamic range of the input signal intensity that the single-photon indium gallium arsenide detector often receives during specific applications. This application does not make any limitations on this, and it depends on the specific situation.

[0079] S33: Sequentially input the time-domain narrow pulse optical signals with different optical intensities into the detector to be corrected for detection, and obtain the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different optical intensities.

[0080] As known from the foregoing, the photocurrent signal output by the single-photon indium gallium arsenide detector is an analog signal. To obtain the response curve of the single-photon indium gallium arsenide detector, it is necessary to quantize the photocurrent signal output by the single-photon indium gallium arsenide detector to form a digital signal, and then input the quantized digital signal into a computer to obtain the response curve of the single-photon indium gallium arsenide detector. Therefore, optionally, in an embodiment of the present application, as Figure 8 shown, sequentially inputting the time-domain narrow pulse optical signals with different optical intensities into the detector to be corrected for detection, and obtaining the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different optical intensities includes:

[0081] S331: Sequentially input the time-domain narrow pulse optical signals with different optical intensities into the detector to be corrected for detection, and obtain the photocurrent signal of the detector to be corrected under the time-domain narrow pulse optical signals with different optical intensities;

[0082] S332: Input the photocurrent signal of the detector to be corrected under the time-domain narrow pulse optical signals with different optical intensities into a multi-channel digital signal acquisition card, and after analog-to-digital conversion, obtain the digital signal of the detector to be corrected under the time-domain narrow pulse optical signals with different optical intensities;

[0083] S333: Input the digital signals of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities into the second controller to obtain the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0084] Specifically, Figure 6 This embodiment also gives a schematic diagram of an implementation manner in which time-domain narrow pulsed optical signals with different light intensities are sequentially input into the detector to be corrected for detection to obtain the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities. From Figure 6 It can be seen that:

[0085] The output end of the electro-optic modulator 20 is connected to the input end of the detector 50 to be corrected, so as to sequentially input the time-domain narrow pulsed optical signals with different light intensities output by the electro-optic modulator 20 into the detector 50 to be corrected to obtain the photocurrent signals of the detector 50 to be corrected under time-domain narrow pulsed optical signals with different light intensities;

[0086] The output end of the detector 50 to be corrected is connected to the input end of the multi-channel digital signal acquisition card 60, so as to input the photocurrent signals of the detector 50 to be corrected under time-domain narrow pulsed optical signals with different light intensities into the multi-channel digital signal acquisition card 60. After analog-to-digital conversion, the digital signals of the detector 50 to be corrected under time-domain narrow pulsed optical signals with different light intensities are obtained;

[0087] The output end of the multi-channel digital signal acquisition card 60 is connected to the input end of the second controller 70, so as to input the digital signals of the detector 50 to be corrected under time-domain narrow pulsed optical signals with different light intensities into the second controller 70 to obtain the response curves of the detector 50 to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0088] It should be noted that in practical applications, the multi-channel digital signal acquisition card 60 can be embedded in the detector 50 to be corrected or can be independent of the detector 50 to be corrected. Figure 6 Only one way in which the multi-channel digital signal acquisition card 60 is independent of the detector 50 to be corrected is listed. In other embodiments of the present application, if the multi-channel digital signal acquisition card 60 is embedded in the detector 50 to be corrected, the output end of the detector 50 to be corrected can be directly connected to the second controller 70. At this time, the signal output from the output end of the detector 50 to be corrected is already the digital signal after analog-to-digital conversion by the multi-channel digital signal acquisition card 60, and thus is directly input into the second controller 70 to obtain the response curve of the detector 50 to be corrected.

[0089] S34: Based on the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, obtain the photon counts detected by the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0090] Based on the above embodiments, in an embodiment of the present application, based on the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, the photon counts detected by the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities include:

[0091] Using the second controller, extract the photon counts corresponding to the peak points of the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, and use them as the photon counts detected by the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0092] As known from the foregoing, the response curve of a single-photon indium gallium arsenide detector under a time-domain narrow pulsed optical signal is in the form of a narrow pulse, that is, it first increases, then decreases, and has a peak point in the middle. Therefore, in this embodiment, using the second controller, extract the photon counts corresponding to the peak points of the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, and use them as the photon counts detected by the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0093] S35: Based on the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities and the calibrated response curves, obtain the afterpulse correction curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0094] It should be noted that the calibrated response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities are the ideal response curves of the detector to be corrected without afterpulse effects under time-domain narrow pulsed optical signals with different light intensities. Therefore, by comparing the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities and the calibrated response curves, obtain the afterpulse correction curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0095] Based on the above embodiments, optionally, in an embodiment of the present application, the process of obtaining the calibrated response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities includes:

[0096] Use an optical fiber splitter to split the time-domain narrow pulsed optical signal output by the electro-optic modulator into two beams. Among them, one beam of time-domain narrow pulsed optical signal is input into the detector to be corrected to sequentially input time-domain narrow pulsed optical signals with different light intensities into the detector to be corrected for detection, and the other beam of time-domain narrow pulsed optical signal is input into a superconducting nanowire detector to sequentially input time-domain narrow pulsed optical signals with different light intensities into the superconducting nanowire detector for detection, and obtain the response curves of the superconducting nanowire detector under time-domain narrow pulsed optical signals with different light intensities, and use them as the calibrated response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0097] It should be noted that since the superconducting nanowire detector has no afterpulse effect, the response curves of the superconducting nanowire detector under time-domain narrow pulsed optical signals with different light intensities can be used as the calibration response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, so as to facilitate the comparison of the response curves of the detector to be corrected and the superconducting nanowire detector under time-domain narrow pulsed optical signals with the same light intensity, obtain the afterpulse correction curve of the corrected detector under the time-domain narrow pulsed optical signal with this light intensity, and then obtain the afterpulse correction curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities.

[0098] It should also be noted that although the superconducting nanowire detector has no afterpulse effect, the superconducting nanowire detector requires relatively harsh operating environments such as high vacuum and ultra-low temperature, and has a relatively large volume, high power consumption, and high cost. While the single-photon indium gallium arsenide detector is smaller in volume, lower in cost, and easier to integrate than the superconducting nanowire detector, and is a better choice for practical 1.5μm lidar. Therefore, in this embodiment, only the response curve of the superconducting nanowire detector is used as the calibration response curve of the detector to be corrected.

[0099] It should be further noted that the time-domain narrow pulsed optical signal output by the electro-optic modulator is split into two beams by an optical fiber splitter. Among them, one beam of time-domain narrow pulsed optical signal is input into the detector to be corrected, and the other beam of time-domain narrow pulsed optical signal is input into the superconducting nanowire detector, so as to sequentially input time-domain narrow pulsed optical signals with different light intensities into the detector to be corrected for detection, obtain the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, and at the same time sequentially input time-domain narrow pulsed optical signals with different light intensities into the superconducting nanowire detector for detection, obtain the response curves of the superconducting nanowire detector under time-domain narrow pulsed optical signals with different light intensities (as the calibration response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities), that is, these two processes are carried out simultaneously, thus saving the work process. However, this application does not limit this. In other embodiments of this application, the process of sequentially inputting time-domain narrow pulsed optical signals with different light intensities into the detector to be corrected for detection to obtain the response curves of the detector to be corrected under time-domain narrow pulsed optical signals with different light intensities, and the process of sequentially inputting time-domain narrow pulsed optical signals with different light intensities into the superconducting nanowire detector for detection to obtain the response curves of the superconducting nanowire detector under time-domain narrow pulsed optical signals with different light intensities can also be carried out separately, depending on the specific situation.

[0100] Specifically, Figure 9 Figure 11 shows a schematic diagram of an implementation manner in which the time-domain narrow pulsed optical signal output by the electro-optic modulator is split by an optical fiber splitter and then respectively connected to the detector to be corrected and the superconducting nanowire detector. From Figure 9 it can be seen that:

[0101] The output end of the electro-optic modulator 20 is connected to the input end of the optical fiber splitter 80, so that the time-domain narrow pulse optical signal output from the electro-optic modulator 20 is split into two beams after passing through the optical fiber splitter 80;

[0102] One output end of the optical fiber splitter 80 is connected to the input end of the detector 50 to be corrected, so as to input a beam of time-domain narrow pulse optical signal split by the optical fiber splitter 60 into the detector 50 to be corrected for detection; the other output end of the optical fiber splitter 80 is connected to the input end of the superconducting nanowire detector 90, so as to input the other beam of time-domain narrow pulse optical signal split by the optical fiber splitter 80 into the superconducting nanowire detector 90 for detection; optionally, the optical fiber splitter 80 can be a 1×2 optical fiber splitter.

[0103] The output ends of the detector 50 to be corrected and the superconducting nanowire detector 90 are both connected to the input end of the multi-channel digital signal acquisition card 60, so as to input the photocurrent signals of the detector 50 to be corrected and the superconducting nanowire detector 90 under the time-domain narrow pulse optical signals with different light intensities into the multi-channel digital signal acquisition card 60 respectively. After analog-to-digital conversion, the digital signals of the detector 50 to be corrected and the superconducting nanowire detector 90 under the time-domain narrow pulse optical signals with different light intensities are obtained respectively;

[0104] The output end of the multi-channel digital signal acquisition card 60 is connected to the input end of the second controller 70, so as to input the digital signals of the detector 50 to be corrected and the superconducting nanowire detector 90 under the time-domain narrow pulse optical signals with different light intensities into the second controller 70, and the response curves of the detector 50 to be corrected and the superconducting nanowire detector 90 under the time-domain narrow pulse optical signals with different light intensities are obtained.

[0105] Optionally, in another embodiment of the present application, the process of obtaining the calibrated response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities includes:

[0106] Under preset conditions, the time-domain narrow pulse optical signals with different light intensities are sequentially input into the detector to be corrected, and the response curve output by the detector to be corrected according to the time-domain narrow pulse optical signals with different light intensities under the preset conditions is obtained as the calibrated response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities.

[0107] It should be noted that the preset conditions refer to the conditions under which the performance of the detector to be corrected is stable and the environment where it is located is stable. At this time, the detector to be corrected has no afterpulse effect or a low afterpulse probability. Therefore, the response curve output by the detector to be corrected according to the time-domain narrow pulse optical signal with different light intensities under the preset conditions can be used as the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signal with different light intensities. Without introducing a superconducting nanowire detector, only by using a single detector to be corrected, the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signal with different light intensities can be obtained.

[0108] It should also be noted that in this embodiment, continuing with the Figure 6 illustrated implementation method as an example, the time-domain narrow pulse optical signal with the same light intensity needs to be input into the detector 50 to be corrected twice for detection. Among them, once under the preset conditions, the time-domain narrow pulse optical signal with this light intensity is input into the detector 50 to be corrected, and the calibration response curve output by the detector 50 to be corrected according to the time-domain narrow pulse optical signal with this light intensity under the preset conditions is obtained. The other time is under the actual working conditions, the time-domain narrow pulse optical signal with this light intensity is input into the detector 50 to be corrected, and the response curve output by the detector 50 to be corrected according to the time-domain narrow pulse optical signal with this light intensity under the actual working conditions is obtained, so as to facilitate comparing the response curves output by the detector 50 to be corrected under the actual working conditions and under the preset conditions according to the time-domain narrow pulse optical signal with this light intensity, obtaining the afterpulse correction curve of the detector 50 to be corrected under the time-domain narrow pulse optical signal with this light intensity, and further obtaining the afterpulse correction curves of the detector 50 to be corrected under the time-domain narrow pulse optical signals with different light intensities.

[0109] Based on any of the above embodiments, in an embodiment of the present application, obtaining the afterpulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities based on the response curve and the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities includes:

[0110] Using the second controller, comparing the response curve and the calibration response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities to obtain the afterpulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities.

[0111] It should be noted that in the above embodiments, not only is the digital signal of the detector to be corrected (and the superconducting nanowire detector) under the time-domain narrow pulse optical signals with different light intensities converted into the response curve of the detector to be corrected (and the superconducting nanowire detector) under the time-domain narrow pulse optical signals with different light intensities by using the second controller, but also the second controller is used to extract the photon count corresponding to the peak point of the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities as the photon count detected by the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities, and the second controller is used to compare the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities with the calibrated response curve to obtain the after-pulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities. Since the above three processes are all carried out in the second controller, these three processes can be carried out simultaneously or separately, and the present application does not make any limitation on this, which depends on the specific situation.

[0112] Based on any one of the above embodiments, optionally, in an embodiment of the present application, as Figure 10 shown, the first controller 30 and the second controller 70 are the same controller, that is, this controller is both used to generate the control signal of the time-domain narrow pulse optical signals with different light intensities, and is also used to obtain the response curve of the detector to be corrected (and the superconducting nanowire detector) under the time-domain narrow pulse optical signals with different light intensities based on the digital signal of the detector to be corrected (and the superconducting nanowire detector) under the time-domain narrow pulse optical signals with different light intensities, and is also used to extract the photon count corresponding to the peak point of the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities as the photon count detected by the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities, and is also used to compare the response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities with the calibrated response curve to obtain the after-pulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities. However, the present application does not make any limitation on this, which depends on the specific situation. Optionally, the first controller 30 and the second controller 70 can be a computer.

[0113] S36: Based on the after-pulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities and the detected photon count, obtain the corresponding relationship between the photon count detected by the detector to be corrected and its after-pulse correction curve.

[0114] Based on any one of the above embodiments, optionally, in an embodiment of the present application, as Figure 11 shown, the process of obtaining the corresponding relationship between the photon count detected by the detector to be corrected and its after-pulse correction curve further includes:

[0115] S37: Create a data table of the correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve, and store it in the detector to be corrected.

[0116] Specifically, creating a data table of the correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve and storing it in the detector to be corrected includes:

[0117] Using the second controller, create a data table of the correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve;

[0118] Download the data table to the detector to be corrected and store it, so that during the actual operation of the detector to be corrected, the response curve of the detector to be corrected under different input signals can be post-pulse corrected in real time.

[0119] It should be noted that this application does not limit whether to create a data table of the correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve, and whether to store the data table in the detector to be corrected. In other embodiments of this application, the correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve can also be called from the second controller, so as to perform post-pulse correction on the response curve of the detector to be corrected under different input signals, depending on the specific situation.

[0120] In summary, the post-pulse correction method for the response curve of the single-photon indium gallium arsenide detector provided by the embodiments of this application obtains the post-pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals according to the photon counts detected by the single-photon indium gallium arsenide detector to be corrected under different input signals and the pre-obtained correspondence between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve, so as to perform post-pulse correction on the response curve of the detector to be corrected when detecting the corresponding photon counts. Compared with the prior art method of using the post-pulse correction curve of the detector to be corrected under a single photon count to perform post-pulse correction on the response curves of the detector to be corrected under different detected photon counts, this method solves the problem that the post-pulse correction curve of the single-photon indium gallium arsenide detector changes with the photon counts it detects, making the response curve of the detector after post-pulse correction more accurate. In particular, it can accurately perform post-pulse correction on the response curve of the single-photon indium gallium arsenide detector under radar echo signals in different weather or environments, thereby improving the stability and reliability of lidar detection data.

[0121] In this specification, each part is described in a combined manner of parallelism and progression. The key points of each part are the differences from other parts. For the same or similar parts between each part, reference can be made to each other.

[0122] Regarding the above description of the disclosed embodiments, the features described in each embodiment in this specification can be replaced or combined with each other, enabling those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for post-pulse correction of the response curve of a single-photon indium gallium arsenide detector, characterized in that, Including: Based on different input signals, obtain the response curves of the detector to be corrected under different input signals. The detector to be corrected is a single-photon indium gallium arsenide detector to be corrected, and the response curve of the detector to be corrected is the corresponding relationship between the photon count detected by the detector based on the input signal and the detection time or detection distance of the input signal; Based on the response curves of the detector to be corrected under different input signals, obtain the photon counts detected by the detector to be corrected under different input signals; Based on the photon counts detected by the detector to be corrected under different input signals and the corresponding relationship between the photon counts detected by the detector to be corrected and the subsequent pulse correction curve obtained in advance, obtain the subsequent pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals; Based on the subsequent pulse correction curve corresponding to the photon counts detected by the detector to be corrected under different input signals, perform subsequent pulse correction on the response curves of the detector to be corrected under different input signals; Among them, the acquisition process of the corresponding relationship between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve includes: Use a laser to generate a continuous laser signal; Use an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulse optical signals with different light intensities, and the light intensity of the time-domain narrow pulse optical signal characterizes the number of photons it contains; Input the time-domain narrow pulse optical signals with different light intensities into the detector to be corrected for detection in sequence to obtain the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities; Based on the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities, obtain the photon counts detected by the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities; Based on the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities and the calibrated response curves, obtain the subsequent pulse correction curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities. Among them, the calibrated response curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities is the ideal response curve without subsequent pulse effect of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities, and the subsequent pulse correction curve of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities is obtained by comparing the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities and the calibrated response curves; Based on the subsequent pulse correction curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities and the detected photon counts, obtain the corresponding relationship between the photon counts detected by the detector to be corrected and its subsequent pulse correction curve.

2. The method according to claim 1, characterized in that Using an electro-optic modulator to modulate the continuous laser signal into time-domain narrow pulse optical signals with different light intensities includes: Use a first controller to generate a control signal for time-domain narrow pulse optical signals with different light intensities; Use a waveform generator to generate a waveform modulation signal for time-domain narrow pulse optical signals with different light intensities based on the control signal for time-domain narrow pulse optical signals with different light intensities; The electro-optic modulator is used to modulate the waveform of the time-domain narrow pulse optical signal based on different light intensities, and the continuous laser signal is modulated into a time-domain narrow pulse optical signal with different light intensities.

3. The method according to claim 1, characterized in that, The time-domain narrow pulse optical signals with different light intensities are sequentially input into the detector to be corrected for detection, and the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities include: The time-domain narrow pulse optical signals with different light intensities are sequentially input into the detector to be corrected for detection, and the photocurrent signals of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities are obtained; The photocurrent signals of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities are input into a multi-channel digital signal acquisition card, and after analog-to-digital conversion, the digital signals of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities are obtained; The digital signals of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities are input into a second controller, and the response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities are obtained.

4. The method according to claim 1, wherein The process of obtaining the calibrated response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities includes: The time-domain narrow pulse optical signal output by the electro-optic modulator is split into two beams by an optical fiber splitter. Among them, one beam of the time-domain narrow pulse optical signal is input into the detector to be corrected to sequentially input the time-domain narrow pulse optical signals with different light intensities into the detector to be corrected for detection, and the other beam of the time-domain narrow pulse optical signal is input into a superconducting nanowire detector to sequentially input the time-domain narrow pulse optical signals with different light intensities into the superconducting nanowire detector for detection, and the response curves of the superconducting nanowire detector under the time-domain narrow pulse optical signals with different light intensities are obtained as the calibrated response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities; Alternatively, under preset conditions, the time-domain narrow pulse optical signals with different light intensities are sequentially input into the detector to be corrected, and the response curves output by the detector to be corrected according to the time-domain narrow pulse optical signals with different light intensities under the preset conditions are obtained as the calibrated response curves of the detector to be corrected under the time-domain narrow pulse optical signals with different light intensities.

5. The method according to claim 1, wherein The process of obtaining the correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curves further includes: The correspondence between the photon counts detected by the detector to be corrected and the subsequent pulse correction curves is made into a data table and stored in the detector to be corrected.

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