Single-photon detector performance parameter measurement method, device, equipment and medium

Abstract

The present application relates to a method, apparatus, device, and medium for measuring the performance parameters of a single-photon detector, which relates to the field of single-photon detection technology. The method includes: calculating and determining the total photon event count value within a first time domain range, calculating and determining the post-pulse event count value within a second time domain range, determining the post-pulse probability of each statistical sub-interval in a statistical histogram based on the post-pulse event count value and the total photon event count value, and determining the post-pulse probability of the single-photon detector to be measured based on the post-pulse probability of each statistical sub-interval; calculating and determining the first difference between the second peak time and the first peak time to determine the dead time of the single-photon detector to be measured; and calculating and determining the time jitter of the single-photon detector to be measured based on the laser pulse width, the time jitter of the synchronization pulse, and the time jitter of the multi-event statistical histogram time-to-digital converter. The present application greatly shortens the measurement time of the performance parameters of a single-photon detector.

Description

Technical Field

[0001] The present application relates to the field of single-photon detection technology, and in particular to a method for measuring performance parameters of a single-photon detector, a corresponding device, an electronic device, and a computer-readable storage medium. Background Art

[0002] Single-photon detectors (SPDs) play a key role in a growing number of cutting-edge photon counting and timing applications, including but not limited to quantum communication, light detection and ranging (LiDAR), and fluorescence lifetime imaging. In photon counting applications, SPDs are combined with counters to record the number of incident photons in real time. However, due to the presence of afterpulses and dead time effects in SPDs, the actual count value often deviates from the true photon count. To eliminate the counting distortion caused by afterpulses and dead time, accurate afterpulse probability and dead time correction are required. In photon timing applications, SPDs are combined with time-correlated single-photon counting (TCSPC) hardware to repeatedly record the arrival times of photons. The statistical histogram of the photon arrival times is then used to reconstruct the temporal intensity distribution of extremely weak incident light pulses. The temporal resolution of the measured signal in this method is primarily determined by the timing jitter of the SPD. Therefore, accurately and reliably characterizing the afterpulse probability, dead time, and timing jitter of SPDs is a key prerequisite for ensuring the accuracy of their photon counting and timing.

[0003] Afterpulsing refers to the phenomenon in which a noise event is randomly generated within a period of time after an initial event (usually generated by a light pulse). The measurement of the probability of afterpulsing usually involves the simultaneous acquisition of the initial event and the noise event. For free-running single-photon detectors, there are three main methods for measuring the probability of afterpulsing: time-correlated carrier counting (TCCC), autocorrelation, and cross-correlation. However, since the TCCC method can only record the first event after the start pulse, the measured afterpulsing probability is always distorted by the pile-up effect, and the low event sampling rate also makes the measurement time of this method very long (usually on the order of tens of minutes). Although the measurement time of the autocorrelation method and the cross-correlation method is usually shorter than that of the TCCC method, the application of these two methods is limited due to the complexity of the autocorrelation and cross-correlation algorithms. The dead time of a single-photon detector is often measured using an oscilloscope, while its timing jitter is often characterized using the TCSPC method. Using these three independent methods to sequentially measure the afterpulse probability, dead time, and timing jitter of a single-photon detector not only greatly increases the measurement time and complexity, but also significantly reduces the efficiency of the instrument equipment.

[0004] To sum up, the use of discrete methods such as time-correlated carrier counting, oscilloscope method and TCSPC method in the existing technology to measure the post-pulse probability, dead time and time jitter of single-photon detectors will not only greatly increase the measurement time and complexity, but also greatly reduce the utilization efficiency of instruments and equipment. This application makes corresponding explorations to solve this problem. Summary of the Invention

[0005] The purpose of this application is to solve the above problems and provide a single-photon detector performance parameter measurement method, corresponding device, electronic device and computer-readable storage medium.

[0006] In order to meet the various objectives of this application, this application adopts the following technical solutions:

[0007] A method for measuring performance parameters of a single-photon detector proposed to meet one of the purposes of this application includes:

[0008] In response to a single-photon detector performance parameter measurement instruction, a multi-event statistical histogram time-to-digital converter is used to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured, so as to generate a statistical histogram of the time interval data;

[0009] Obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determining a first time domain range corresponding to the photon event based on the first peak time, and using a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time;

[0010] Calculate and determine the total photon event count value within the first time domain range, calculate and determine the afterpulse event count value within the second time domain range, determine the afterpulse probability corresponding to each statistical subinterval in the statistical histogram based on the afterpulse event count value and the total photon event count value, and determine the afterpulse probability corresponding to the single-photon detector to be measured based on the afterpulse probability corresponding to each statistical subinterval;

[0011] Calculating and determining a first difference between the second peak time and the first peak time to determine a dead time corresponding to the single-photon detector to be measured;

[0012] The time jitter of the single-photon detector to be measured is calculated and determined based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter to complete the measurement of the single-photon detector performance parameters.

[0013] Optionally, before the step of using a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data, the method includes:

[0014] The trigger signal generator module outputs two synchronous pulses, wherein one synchronous pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronous pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box through the optical fiber. The light output from the optical fiber is first collimated by a collimator, then attenuated by an adjustable attenuation plate, and then focused by an objective lens to the center of the photosensitive surface of the single-photon detector to be measured, so as to output the end pulse of the multi-event statistical histogram time-to-digital converter.

[0015] Optionally, the step of using a multi-event statistical histogram time-to-digital converter to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data includes:

[0016] The multi-event statistical histogram time-to-digital converter is used to record the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured;

[0017] Determine the time interval range corresponding to each statistical subinterval in the statistical histogram, and distribute the time interval data generated by the single-photon detector to be measured under the action of each photon event to the time interval range corresponding to each statistical subinterval to construct a statistical histogram of the time interval data, wherein the statistical subinterval represents the frequency or frequency of occurrence of each photon event within a certain time interval.

[0018] Optionally, the step of obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram includes:

[0019] In response to an instruction to correct a dark count effect of a single-photon detector to be measured, obtaining an original photon event count value measured in each statistical subinterval in the statistical histogram, a dark count rate of the single-photon detector to be measured, a time interval length of the statistical subinterval, a repetition frequency of the laser pulse, and a total data acquisition time;

[0020] Calculating and determining a first product among the dark count rate of the single-photon detector to be measured, the time interval length of the statistical subinterval, the repetition frequency of the laser pulse, and the total data acquisition time, and calculating and determining a second difference between the original photon event count value and the first product to determine a corrected photon event count value in each statistical subinterval in the statistical histogram;

[0021] The time domain distribution of net photon events and post-pulse events is determined based on the corrected photon event count value in each statistical sub-interval in the statistical histogram, and peak search processing is performed based on the time domain distribution of the net photon events and post-pulse events to determine the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram.

[0022] Optionally, the steps of calculating and determining a total photon event count value within the first time domain range, calculating and determining a post-pulse event count value within the second time domain range, determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the post-pulse event count value and the total photon event count value, and determining a post-pulse probability corresponding to the single-photon detector to be measured based on the post-pulse probability corresponding to each statistical subinterval include:

[0023] Calculating and determining all photon event count values ​​within a first time domain corresponding to a photon event in each statistical subinterval in the statistical histogram to determine a total photon event count value within the first time domain of each statistical subinterval in the statistical histogram;

[0024] Calculating and determining a post-pulse event count value within a second time domain range corresponding to a post-pulse event in each statistical subinterval in the statistical histogram, and determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on a first ratio between the post-pulse event count value and the total photon event count value;

[0025] A first sum value between the after-pulse probabilities corresponding to each statistical subinterval in the statistical histogram is calculated to determine the after-pulse probability corresponding to the single-photon detector to be measured.

[0026] Optionally, the step of calculating and determining the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter includes:

[0027] Acquire the full width at half maximum of the photon event peak, the laser pulse width, the time jitter corresponding to the synchronization pulse, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter;

[0028] Calculating and determining a first square value of the full width at half maximum of the photon event peak, a second square value of the laser pulse width, a third square value of the time jitter corresponding to the synchronization pulse, and a fourth square value of the time jitter corresponding to the multi-event statistical histogram time-to-digital converter;

[0029] A second sum of the second square value, the third square value, and the fourth square value is calculated and determined, a third difference between the first square value and the second sum is calculated and determined, and the time jitter of the single-photon detector to be measured is determined according to the square root of the third difference.

[0030] Optionally, the amplitude of the photon event peak is higher than the amplitude of the post-pulse event, and the post-pulse event peak appears after the photon event peak;

[0031] The full width at half maximum of the photon event peak represents the horizontal distance between the intersection of the curve and the baseline when the peak height of the photon event peak is half. The smaller the horizontal distance, the higher the time resolution of the system.

[0032] The single-photon detector to be measured includes a photomultiplier tube or a single-photon avalanche diode;

[0033] The single-photon detector performance parameters include the after-pulse probability, dead time and time jitter of the single-photon detector.

[0034] A single-photon detector performance parameter measurement device provided for another purpose of the present application includes:

[0035] a statistical histogram construction module, configured to respond to a single-photon detector performance parameter measurement instruction, and use a multi-event statistical histogram time-to-digital converter to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured, so as to generate a statistical histogram of the time interval data;

[0036] a time domain range determination module, configured to obtain a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determine a first time domain range corresponding to the photon event based on the first peak time, and use a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time;

[0037] a post-pulse probability determination module, configured to calculate and determine a total photon event count value within the first time domain range, calculate and determine a post-pulse event count value within the second time domain range, determine a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the post-pulse event count value and the total photon event count value, and determine a post-pulse probability corresponding to the single-photon detector to be measured based on the post-pulse probability corresponding to each statistical subinterval;

[0038] a dead time determination module, configured to calculate and determine a first difference between the second peak time and the first peak time, so as to determine a dead time corresponding to the single-photon detector to be measured;

[0039] The time jitter determination module is configured to calculate and determine the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter, so as to complete the measurement of the performance parameters of the single-photon detector.

[0040] An electronic device provided to meet another purpose of the present application includes a central processing unit and a memory, wherein the central processing unit is used to call and run a computer program stored in the memory to execute the steps of the single-photon detector performance parameter measurement method described in the present application.

[0041] A computer-readable storage medium is provided to meet another purpose of the present application, which stores a computer program implemented according to the single-photon detector performance parameter measurement method in the form of computer-readable instructions. When the computer program is called and executed by a computer, the steps included in the corresponding method are executed.

[0042] Compared with the existing technology, the present application uses separate methods to measure the afterpulse probability, dead time, and time jitter of single-photon detectors respectively, which not only greatly increases the measurement time and complexity, but also greatly reduces the efficiency of the instrument equipment. The present application has, but is not limited to, the following beneficial effects:

[0043] First, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter can capture multiple photon events simultaneously, and can independently detect and record photon events and post-pulse events within the same time period. When a photon event is detected, the operating mechanism of the system does not change the probability of detecting a post-pulse event due to the occurrence of the photon event;

[0044] Secondly, the single-photon detector performance parameter measurement method of the present application and the multi-event statistical histogram time-to-digital converter avoid the interference of the pile-up effect on the detection probability of the after-pulse event, making the measured after-pulse probability more accurate and reliable, and can truly reflect the actual situation of the after-pulse event;

[0045] Third, the single-photon detector performance parameter measurement method of this application, the multi-event statistical histogram time-to-digital converter, has ultra-high temporal resolution, enabling it to precisely record the time of event occurrence. During the measurement process, the accurate recording of the time information of photon events and related physical phenomena facilitates more accurate analysis and understanding of the measurement results, thereby improving measurement accuracy. Compared with traditional discrete methods, it can capture the details and temporal characteristics of events in greater detail, reducing errors caused by inaccurate time measurements.

[0046] Fourthly, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has on-chip histogram statistics capability, which can directly perform histogram statistics on the measurement data on the chip, without the need to transmit the data to an external device for statistical histogram processing, greatly improving the efficiency of data processing. In this way, the distribution information of the measurement results can be quickly obtained;

[0047] Fifth, the single-photon detector performance parameter measurement method of the present application can complete the collection and processing of large amounts of data in a short period of time, shortening the measurement time to minutes. This greatly shortens the measurement time of single-photon detector performance parameters such as afterpulse probability, dead time, and time jitter. Compared with traditional technologies, the measurement time of the present application is reduced by an order of magnitude, which is of great significance in practical applications. For example, it can improve experimental efficiency, reduce measurement costs, and obtain experimental results more quickly to guide subsequent work.

[0048] Furthermore, the single-photon detector performance parameter measurement method of the present application has technical advantages such as simplicity, high efficiency, and wide applicability. It does not require complicated operating steps and a large amount of manual intervention, can quickly obtain accurate measurement results, and greatly reduces the waiting time and resource consumption during the measurement process. Whether in basic physics experiments, materials science research, biomedical testing or other related fields, it has strong versatility and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0050] Figure 1 Schematic diagram of the process of measuring the performance parameters of a single-photon detector in an embodiment of the present application;

[0051] Figure 2 A schematic diagram of a process for generating a statistical histogram of time interval data in an embodiment of the present application;

[0052] Figure 3 This is an exemplary network architecture of the single-photon detector performance parameter measurement system in the embodiment of the present application;

[0053] Figure 4 Schematic diagram of the timing of simultaneous measurement of the post-pulse probability, dead time, and time jitter of a single-photon detector in an embodiment of the present application;

[0054] Figure 5 Schematic diagram of a process for determining the first peak time of a photon event peak and the second peak time of a post-pulse event peak in an embodiment of the present application;

[0055] Figure 6 Schematic diagram of the time domain probability distribution of photon events and post-pulse events measured in an embodiment of the present application;

[0056] Figure 7 Schematic diagram of a process for determining the afterpulse probability corresponding to the single-photon detector to be measured in an embodiment of the present application;

[0057] Figure 8 Schematic diagram of a process for determining the time jitter of a single-photon detector to be measured in an embodiment of the present application;

[0058] Figure 9 This is a principle block diagram of a device for measuring performance parameters of a single-photon detector in an embodiment of the present application;

[0059] Figure 10 Schematic diagram of the structure of the computer device in the embodiment of the present application.

[0060] Reference numerals:

[0061] 101 signal generator module, 102 ultrashort pulse laser module, 103 optical fiber, 111 collimating mirror, 112 adjustable attenuator, 113 objective lens, 121 single photon detector to be measured, 131 multi-event statistical histogram time-to-digital converter, 141 darkroom, 151 computer. DETAILED DESCRIPTION

[0062] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and are not to be construed as limiting the present application.

[0063] It will be understood by those skilled in the art that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. In addition, "connected" or "coupled" as used herein may include wireless connections or wireless couplings. The term "and / or" used herein includes all or any units and all combinations of one or more associated listed items.

[0064] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0065] It will be understood by those skilled in the art that the terms "client," "terminal," and "terminal device" as used herein include both devices that are wireless signal receivers, i.e., devices that only have wireless signal receivers without transmission capabilities, and devices that have receiving and transmitting hardware capable of two-way communication over a two-way communication link. Such devices may include: cellular or other communication devices such as personal computers and tablet computers, which have single-line displays, multi-line displays, or cellular or other communication devices without multi-line displays; PCS (Personal Communications Service), which may combine voice, data processing, fax, and / or data communication capabilities; PDA (Personal Digital Assistant), which may include a radio frequency receiver, a pager, Internet / Intranet access, a web browser, a notepad, a calendar, and / or a GPS (Global Positioning System) receiver; and conventional laptop and / or palmtop computers or other devices, which have and / or include a radio frequency receiver. As used herein, the terms "client," "terminal," or "terminal device" may be portable, transportable, or installed in a vehicle (air, sea, and / or land), or may be adapted and / or configured to operate locally and / or in a distributed manner at any other location on Earth and / or in space. As used herein, the terms "client," "terminal," or "terminal device" may also refer to a communication terminal, an Internet terminal, or a music / video playback terminal, such as a PDA, an MID (Mobile Internet Device), and / or a mobile phone with music / video playback capabilities, or may include a smart TV, a set-top box, or other device.

[0066] The hardware referred to by names such as "server", "client", and "service node" in this application is essentially an electronic device with capabilities equivalent to those of a personal computer. It is a hardware device that has the necessary components revealed by the von Neumann principle, such as a central processing unit (including an arithmetic unit and a controller), a memory, an input device, and an output device. Computer programs are stored in its memory, and the central processing unit loads the program stored in the external memory into the internal memory for execution, executes the instructions in the program, and interacts with the input and output devices to complete specific functions.

[0067] It should be noted that the concept of "server" referred to in this application can also be extended to server clusters. Based on the network deployment principles understood by those skilled in the art, the servers described should be logically divided. In physical space, these servers can be independent of each other but callable through interfaces, or integrated into a single physical computer or a computer cluster. Those skilled in the art should understand this flexibility and should not use it to constrain the implementation of the network deployment method of this application.

[0068] Unless expressly specified, one or more technical features of the present application can be deployed on a server for implementation and accessed by a client through a remote call to obtain an online service interface provided by the server, or can be directly deployed and run on a client for implementation.

[0069] Unless expressly specified otherwise, the neural network models referenced or may be referenced in this application may be deployed on a remote server and remotely called on the client, or may be deployed and directly called on a client with sufficient device capabilities. In some embodiments, when it runs on the client, its corresponding intelligence may be obtained through transfer learning to reduce the requirements for the client's hardware operating resources and avoid excessive occupation of the client's hardware operating resources.

[0070] Unless explicitly specified, the various data involved in this application can be stored remotely on a server or on a local terminal device, as long as they are suitable for being called by the technical solution of this application.

[0071] Those skilled in the art should be aware that although the various methods of this application are described based on the same concept and thus exhibit commonality, unless otherwise specified, these methods can be independently executed. Similarly, the various embodiments disclosed in this application are all based on the same inventive concept. Therefore, concepts with the same expression, as well as concepts that are appropriately transformed for convenience despite different expression, should be understood as equivalent.

[0072] Unless expressly stated to be mutually exclusive, the various embodiments disclosed in this application may be cross-combined with the relevant technical features of the various embodiments to flexibly construct new embodiments, as long as such combination does not deviate from the creative spirit of this application and can meet the needs of the prior art or resolve certain deficiencies in the prior art. Those skilled in the art should be aware of such flexibility.

[0073] See also Figure 1 In one embodiment, the single-photon detector performance parameter measurement method of the present application includes:

[0074] Step S10, responding to a single-photon detector performance parameter measurement instruction, using a multi-event statistical histogram time-to-digital converter to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured, to generate a statistical histogram of the time interval data;

[0075] A single-photon detector performance parameter measurement system can respond to a single-photon detector performance parameter measurement instruction and use a multi-event histogramming time-to-digital converter (ME-HTDC) to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data, wherein the single-photon detector to be measured includes but is not limited to a photomultiplier tube or a single-photon avalanche diode, etc.; the single-photon detector performance parameters include but are not limited to the after-pulse probability, dead time, and time jitter of the single-photon detector.

[0076] In some embodiments, the multieventhistogramming time-to-digital converter (ME-HTDC) of the present application has the following features:

[0077] First, the multi-event statistical histogram time-to-digital converter of the present application has the capability of capturing multiple events, and the dead time between events is much smaller than the dead time of the detector under test, that is, the event sampling rate of the multi-event statistical histogram time-to-digital converter (ME-HTDC) is sufficiently high;

[0078] Secondly, the multi-event statistical histogram time-to-digital converter of the present application has an on-chip histogram statistics capability, that is, the multi-event statistical histogram time-to-digital converter performs real-time histogram statistics on the measured time intervals on the chip, and does not output the statistics until a statistically significant histogram is generated, thereby reducing the amount of data transmission and the resources occupied;

[0079] Third, the time resolution of the multi-event statistical histogram time-to-digital converter and the pulse width of the ultrashort pulse laser of the present application are much smaller than the time jitter of the single-photon detector to be measured;

[0080] Fourthly, the dynamic range of the multi-event statistical histogram time-to-digital converter of the present application is much larger than the duration of the pulse probability after the single-photon detector to be measured;

[0081] Fifth, the laser pulse output by the ultrashort pulse laser module of the present application is attenuated and focused and then irradiated onto the central area of ​​the photosensitive surface of the single-photon detector to be measured. The pulse output by the single-photon detector to be measured serves as the end pulse of the multi-event statistical histogram time-to-digital converter, and the synchronization pulse of the ultrashort laser pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter. The time jitter between the synchronization pulses is much smaller than the time jitter of the single-photon detector to be measured.

[0082] Sixth, under ultrashort laser pulse irradiation, the statistical histogram (i.e., time-domain probability distribution) measured by the multi-event statistical histogram time-to-digital converter contains the time-resolved performance parameters of the single-photon detector to be measured, such as afterpulse probability, dead time, and time jitter.

[0083] In some embodiments, see Figure 2 The step of using a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data includes:

[0084] Step S101, using the multi-event statistical histogram time-to-digital converter to record the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured;

[0085] Step S102: determine the time interval range corresponding to each statistical sub-interval in the statistical histogram, and distribute the time interval data generated by the single-photon detector to be measured under the action of each photon event to the time interval range corresponding to each statistical sub-interval to construct a statistical histogram of the time interval data, wherein the statistical sub-interval represents the frequency or frequency of occurrence of each photon event within a certain time interval.

[0086] In some embodiments, before the step of using a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data, the method includes:

[0087] The trigger signal generator module outputs two synchronous pulses, wherein one synchronous pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronous pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box through the optical fiber. The light output from the optical fiber is first collimated by a collimator, then attenuated by an adjustable attenuation plate, and then focused by an objective lens to the center of the photosensitive surface of the single-photon detector to be measured, so as to output the end pulse of the multi-event statistical histogram time-to-digital converter.

[0088] Specifically, see Figure 3The single-photon detector performance parameter measurement system mainly includes a signal generator module 101, an ultrashort pulse laser module 102, an optical fiber 103, a collimating lens 111, an adjustable attenuator 112, an objective lens 113, a single-photon detector to be measured 121, a multi-event statistical histogram time-to-digital converter 131, a darkroom 141 and a computer 151.

[0089] The signal generator module 101 outputs two synchronous pulses, one synchronous pulse is used as the starting pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronous pulse is used to trigger the ultrashort pulse laser module 102 to emit a laser pulse to the photosensitive surface of the single-photon detector 121 to be measured, so as to output the ending pulse of the multi-event statistical histogram time-to-digital converter 131. The laser pulse emitted by the ultrashort pulse laser module 102 is introduced into the dark box 141 through the optical fiber 103. The light output from the optical fiber 103 is first collimated by the collimator 111 and then attenuated by the adjustable attenuator 112. Objective lens 113 focuses light onto the center of the photosensitive surface of single-photon detector 121 to be measured. The output of single-photon detector 121 is connected to the terminal end of multi-event statistical histogram time-to-digital converter 131 for measuring the temporal probability distribution of events. Computer 151 is connected to multi-event statistical histogram time-to-digital converter 131 to read and store the measurement results from multi-event statistical histogram time-to-digital converter 131 and perform subsequent processing to calculate performance parameters of single-photon detector 121 to be measured, such as the afterpulse probability, dead time, and time jitter of the single-photon detector. Furthermore, computer 151 is connected to signal generator module 101 to control the parameters of the synchronization pulse.

[0090] The adjustable attenuation plate 112 is used to attenuate the incident light pulse to the single-photon level to eliminate the single-photon time jitter offset caused by the simultaneous action of multiple photons; the objective lens 113 is used to focus the laser beam so that its diameter is smaller than the photosensitive surface size of the single-photon detector to be measured, so as to reduce the influence of the edge of the photosensitive area of ​​the single-photon detector on the single-photon time jitter measurement; the period of the synchronization pulse is consistent with the dynamic range of the multi-event statistical histogram time-to-digital converter 131, and the delay time between the synchronization pulse and the laser pulse is set appropriately to ensure that the multi-event statistical histogram time-to-digital converter 131 can measure the complete relaxation process of the post-pulse probability; after countless cycles of measurement, a statistical histogram of the time domain distribution of photon events, post-pulse events, and dark pulse events is obtained.

[0091] More specifically, the single-photon detector performance parameter measurement system of the present application is applicable to all common single-photon detectors, such as single-photon avalanche diodes, photomultiplier tubes, etc., and the single-photon avalanche diodes include but are not limited to silicon single-photon avalanche diodes, germanium single-photon avalanche diodes, and gallium nitride single-photon avalanche diodes, etc.

[0092] This embodiment takes a silicon single-photon avalanche diode as an example, which does not limit the present application. Since the silicon single-photon avalanche diode can respond to photons in the range of 400 to 1100nm, the ultrashort pulse laser module 102 in this embodiment adopts a picosecond diode laser with a wavelength of 774nm, and the time width of its pulse is 54ps. In view of the fact that it is easy to implement a high-performance multi-event statistical histogram time-to-digital converter based on a field programmable gate array (FPGA), this embodiment selects a multi-event statistical histogram time-to-digital converter based on a field programmable gate array as an example. The time resolution of the multi-event statistical histogram time-to-digital converter is 27ps and the dynamic range is 1000ns. Taking into account that the period of the laser pulse needs to match the dynamic range of the multi-event statistical histogram time-to-digital converter, the repetition frequency of the synchronization pulse (i.e., laser pulse) in this embodiment is set to 1.0MHz.

[0093] The signal generator module 101 outputs two synchronous TTL pulses with a frequency of 1.0 MHz. One pulse is used to trigger the ultrashort pulse laser module 102 to emit laser pulses, and the other pulse is used as the starting pulse of the multi-event statistical histogram time-to-digital converter. The laser pulse emitted by the ultrashort pulse laser module 102 is introduced into the dark box 141 via the optical fiber 103, wherein the laser pulse has a pulse duration of 54 ps, a laser wavelength of 774 nm, and a frequency of 1.0 MHz. The light emitted from the end of the optical fiber 103 is first collimated by a collimator 111, then attenuated by an adjustable attenuator 112 to the single-photon level, and is focused by an objective lens 113 onto the center of the photosensitive surface of the single-photon detector 121 to be measured. The output of the single-photon detector 121 to be measured is connected to the end of a multi-event statistical histogram time-to-digital converter 131 for measuring the time-domain probability distribution of events. A computer 151 is connected to the multi-event statistical histogram time-to-digital converter 131 for reading and storing the statistical histogram measured by the multi-event statistical histogram time-to-digital converter, performing subsequent processing, and calculating and displaying performance parameters of the single-photon detector to be measured, such as afterpulse probability, dead time, and time jitter.

[0094] See also Figure 4 , Figure 4Figure 2 shows the timing of simultaneously measuring the post-pulse probability, dead time, and time jitter of a single-photon detector based on a multiple-event statistical histogram time-to-digital converter (ME-HTDC). Timing 21 represents the synchronization pulses of the picosecond diode laser and the ME-HTDC, one of which is used to trigger the picosecond diode laser and the other as the start pulse of the ME-HTDC. Timing 22 represents the light pulse emitted by the laser. Timing 23 represents the output pulse of the single-photon detector to be measured (including photon events, post-pulse events, and dark pulse events), which serves as the end pulse of the ME-HTDC. Timing 24 represents the time interval between the end pulse (single or multiple) and the start pulse measured by the ME-HTDC. Timing 25 represents the on-chip real-time histogram statistics results.

[0095] The timing of the synchronous pulse, ultrashort laser pulse, the output of the single photon detector to be measured, and the multi-event statistical histogram time-to-digital converter measurement is as follows: Figure 4 As shown in the figure, after measuring countless pulse cycles, the statistical histogram of the time domain distribution of photon events, after-pulse events, and dark pulse events is obtained. The total data acquisition time is 3 minutes, which is much shorter than the acquisition time based on the traditional discrete method (t acq >60min) was reduced by 20-fold.

[0096] Step S20: Obtain a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determine a first time domain range corresponding to the photon event based on the first peak time, and use a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time;

[0097] A multi-event statistical histogram time-to-digital converter is used to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured. After generating a statistical histogram of the time interval data, the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram are obtained. The first time domain range corresponding to the photon event is determined based on the first peak time, and the time domain range exceeding the second peak time is used as the second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time; the amplitude of the photon event peak is higher than the amplitude of the post-pulse event, and the post-pulse event peak appears after the photon event peak; the full width at half maximum of the photon event peak represents the horizontal distance between the intersection points of the curve and the baseline when the full width at half maximum of the photon event peak is half the peak height of the photon event peak. The smaller the horizontal distance, the higher the system time resolution.

[0098] In some embodiments, see Figure 5 , the step of obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram comprises:

[0099] Step S201, in response to an instruction to correct a dark count effect of a single-photon detector to be measured, obtaining an original photon event count value measured in each statistical subinterval in the statistical histogram, a dark count rate of the single-photon detector to be measured, a time interval length of the statistical subinterval, a repetition frequency of the laser pulse, and a total data acquisition time;

[0100] Step S202: calculating and determining a first product among the dark count rate of the single-photon detector to be measured, the time interval length of the statistical subinterval, the repetition frequency of the laser pulse, and the total data acquisition time; calculating and determining a second difference between the original photon event count value and the first product, so as to determine a corrected photon event count value in each statistical subinterval in the statistical histogram;

[0101] Step S203: determine the time domain distribution of net photon events and post-pulse events based on the corrected photon event count value in each statistical sub-interval in the statistical histogram, and perform peak search processing based on the time domain distribution of the net photon events and post-pulse events to determine the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram.

[0102] Specifically, in the step of obtaining the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical subinterval in the statistical histogram, it is necessary to correct the dark count effect of the single-photon detector to be measured to obtain the time domain distribution of the net photon event and the post-pulse event. The expression for correcting the dark count effect of the single-photon detector to be measured is:

[0103] C cor (i) = C m (i)-DCR·δt·f l ·t acq ,

[0104] Among them, C cor (i) represents the corrected photon event count value in each statistical subinterval in the statistical histogram; C m (i) represents the original photon event count value measured in each statistical subinterval in the statistical histogram; DCR represents the dark count rate of the single-photon detector to be measured; δt is the width of the statistical subinterval, which represents the time interval length of the statistical subinterval; f lrepresents the repetition frequency of the laser pulse; t acq It represents the total data collection time (in seconds). The time axis of the statistical histogram is calculated and determined by t=i·δt.

[0105] Based on the above expression, it is possible to calculate and determine the corrected photon event count value in each statistical sub-interval in the statistical histogram, determine the time domain distribution of the net photon event and the post-pulse event based on the corrected photon event count value in each statistical sub-interval in the statistical histogram, and perform peak searching based on the time domain distribution of the net photon event and the post-pulse event to determine the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram.

[0106] Based on any embodiment of this application, please refer to Figure 6 , Figure 6 The time domain probability distribution of photon events and post-pulse events of a silicon single-photon avalanche diode single-photon detector measured under 774nm picosecond pulse laser irradiation is obtained based on the multi-event statistical histogram time-to-digital converter. Figure 6 The results show that the dead time of the silicon single-photon detector is 44.6ns, which is basically consistent with the dead time measured by the traditional oscilloscope method (44.5ns). The timing jitter of the silicon single-photon detector is 304ps, which is very consistent with the timing jitter measured by the traditional TCSPC method (299ps). The consistency of these experimental results shows that the performance parameters of silicon single-photon detectors are very stable and reliable in terms of timing accuracy through the single-photon detector performance parameter measurement method of this application.

[0107] See also Figure 6 , based on the corrected photon event count value in each statistical subinterval, peak search processing is performed to obtain the time corresponding to the peak value of peak I and the time corresponding to the peak value of peak II, where peak I represents the photon event peak, and the first peak time corresponding to the photon event peak is recorded as t pkI Peak II represents the post-pulse event peak, and the second peak time corresponding to the post-pulse event peak is recorded as t pkII Among them, the amplitude of peak I is higher and is caused by the photon event, while the amplitude of peak II is much lower and is caused by the post-pulse event, and t≥t pkII The distribution of represents the time domain distribution of the afterpulse, that is, the second time domain range corresponding to the afterpulse event.

[0108] Through the above steps, the dark count effect of the single-photon detector to be measured can be effectively corrected, and the time domain distribution and peak time of photon events and after-pulse events can be accurately determined. This method can effectively remove the dark count effect, improve the accuracy of photon detection, and provide accurate data support for the measurement of performance parameters such as after-pulse probability, dead time, and time jitter of the single-photon detector.

[0109] Step S30, calculating and determining the total photon event count value within the first time domain range, calculating and determining the after-pulse event count value within the second time domain range, determining the after-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the after-pulse event count value and the total photon event count value, and determining the after-pulse probability corresponding to the single-photon detector to be measured based on the after-pulse probability corresponding to each statistical subinterval;

[0110] Obtaining a first peak time corresponding to a photon event peak (peak I) and a second peak time corresponding to a post-pulse event peak (peak II) in each statistical subinterval in the statistical histogram, determining a first time domain range corresponding to the photon event based on the first peak time, taking a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, calculating and determining a total photon event count value within the first time domain range, calculating and determining a post-pulse event count value within the second time domain range, determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the post-pulse event count value and the total photon event count value, and determining a post-pulse probability corresponding to the single-photon detector to be measured based on the post-pulse probability corresponding to each statistical subinterval;

[0111] In some embodiments, see Figure 7 , calculating and determining a total photon event count value within the first time domain range, calculating and determining a post-pulse event count value within the second time domain range, determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the post-pulse event count value and the total photon event count value, and determining a post-pulse probability corresponding to the single-photon detector to be measured based on the post-pulse probability corresponding to each statistical subinterval, comprising:

[0112] Step S301: Calculate and determine all photon event count values ​​within a first time domain corresponding to a photon event in each statistical subinterval in the statistical histogram to determine a total photon event count value within the first time domain of each statistical subinterval in the statistical histogram;

[0113] Step S302: Calculate and determine a post-pulse event count value within a second time domain range corresponding to a post-pulse event in each statistical subinterval in the statistical histogram, and determine a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on a first ratio between the post-pulse event count value and the total photon event count value;

[0114] Step S303 : Calculate and determine a first sum value between the after-pulse probabilities corresponding to each statistical subinterval in the statistical histogram to determine the after-pulse probability corresponding to the single-photon detector to be measured.

[0115] Specifically, all photon event count values ​​within a first time domain range corresponding to the photon events of each statistical subinterval in the statistical histogram are calculated and determined, that is, all photon event count values ​​contained in the photon event peak (peak I) are summed to determine the total photon event count value within the first time domain range of each statistical subinterval in the statistical histogram; the post-pulse event count value within a second time domain range corresponding to the post-pulse event of each statistical subinterval in the statistical histogram is calculated and determined, and based on a first ratio between the post-pulse event count value and the total photon event count value, the post-pulse probability corresponding to each statistical subinterval in the statistical histogram is determined, wherein the time within the second time domain range is greater than or equal to the second peak time corresponding to the post-pulse event peak;

[0116] The afterpulse probability corresponding to each statistical subinterval in the statistical histogram is expressed as:

[0117]

[0118] Among them, P ap (i) represents the post-pulse probability corresponding to the i-th statistical subinterval in the statistical histogram, C cor (i) represents the post-pulse event count value in the second time domain corresponding to the post-pulse event in the i-th statistical subinterval in the statistical histogram; C ph Represents all photon event count values ​​in the first time domain range corresponding to the photon event in the i-th statistical sub-interval in the statistical histogram.

[0119] Step S40: calculating and determining a first difference between the second peak time and the first peak time to determine a dead time corresponding to the single-photon detector to be measured;

[0120] Obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determining a first time domain range corresponding to the photon event based on the first peak time, taking a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, and calculating and determining a first difference between the second peak time and the first peak time to determine a dead time corresponding to the single-photon detector to be measured;

[0121] As can be seen from the above embodiment, a set of photon event data is collected by the single-photon detector to be measured. Each photon event corresponds to a timestamp, and these timestamps are distributed in a statistical histogram. All photon event data are arranged in chronological order, and based on the distribution of each sub-interval in the statistical histogram, the first photon event peak in each sub-interval is identified. Each photon event peak represents a local maximum, and its corresponding time point is the first peak time. After the first peak time of the photon event, the second peak of the post-pulse event is searched and identified. This peak usually occurs some time after the first peak. The time of the second peak is determined and used as the second peak time. Starting from the first peak time, an appropriate time domain range is selected to define the time domain distribution of the photon event. This can be determined by setting a fixed time window or based on the decrease in signal intensity. After the second peak time, a time domain range is selected as the time domain of the post-pulse event. This time domain should ensure that all important signals of the post-pulse are covered. The time difference between the first peak time and the second peak time is calculated to obtain a first difference value to determine the dead time corresponding to the single-photon detector to be measured.

[0122] Step S50: Calculate and determine the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter to complete the measurement of the single-photon detector performance parameters.

[0123] After calculating and determining a first difference between the second peak time and the first peak time to determine the dead time corresponding to the single-photon detector to be measured, the time jitter of the single-photon detector to be measured is calculated and determined based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter to complete the measurement of the single-photon detector performance parameters.

[0124] In some embodiments, see Figure 8The step of calculating and determining the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter includes:

[0125] Step S501, obtaining the full width at half maximum of the photon event peak, the laser pulse width, the time jitter corresponding to the synchronization pulse, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter;

[0126] Step S502, calculating and determining a first square value of the full width at half maximum of the photon event peak, a second square value of the laser pulse width, a third square value of the time jitter corresponding to the synchronization pulse, and a fourth square value of the time jitter corresponding to the multi-event statistical histogram time-to-digital converter;

[0127] Step S503: Calculate and determine a second sum of the second square value, the third square value, and the fourth square value, calculate and determine a third difference between the first square value and the second sum, and determine the time jitter of the single-photon detector to be measured according to the square root of the third difference.

[0128] Specifically, the calculation formula for the time jitter of the single-photon detector to be measured is expressed as:

[0129]

[0130] Among them, σ m represents the full width at half maximum of the photon event peak (peak I); ​​σ l represents the pulse width of the laser pulse; σ SYNC Indicates the time jitter corresponding to the synchronization pulse; σ ME-HTDC Indicates the time jitter corresponding to the multi-event statistical histogram time-to-digital converter; σ SPD Represents the timing jitter of the single-photon detector to be measured.

[0131] Compared with the existing technology, the present application uses separate methods to measure the afterpulse probability, dead time, and time jitter of single-photon detectors respectively, which not only greatly increases the measurement time and complexity, but also greatly reduces the efficiency of the instrument equipment. The present application has, but is not limited to, the following beneficial effects:

[0132] First, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter can capture multiple photon events simultaneously, and can independently detect and record photon events and post-pulse events within the same time period. When a photon event is detected, the operating mechanism of the system does not change the probability of detecting a post-pulse event due to the occurrence of the photon event;

[0133] Secondly, the single-photon detector performance parameter measurement method of the present application and the multi-event statistical histogram time-to-digital converter avoid the interference of the pile-up effect on the detection probability of the after-pulse event, making the measured after-pulse probability more accurate and reliable, and can truly reflect the actual situation of the after-pulse event;

[0134] Third, the single-photon detector performance parameter measurement method of this application, the multi-event statistical histogram time-to-digital converter, has ultra-high temporal resolution, enabling it to precisely record the time of event occurrence. During the measurement process, the accurate recording of the time information of photon events and related physical phenomena facilitates more accurate analysis and understanding of the measurement results, thereby improving measurement accuracy. Compared with traditional discrete methods, it can capture the details and temporal characteristics of events in greater detail, reducing errors caused by inaccurate time measurements.

[0135] Fourthly, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has on-chip histogram statistics capability, which can directly perform histogram statistics on the measurement data on the chip, without the need to transmit the data to an external device for statistical histogram processing, greatly improving the efficiency of data processing. In this way, the distribution information of the measurement results can be quickly obtained;

[0136] Fifth, the single-photon detector performance parameter measurement method of the present application can complete the collection and processing of large amounts of data in a short period of time, shortening the measurement time to minutes. This greatly shortens the measurement time of single-photon detector performance parameters such as afterpulse probability, dead time, and time jitter. Compared with traditional technologies, the measurement time of the present application is reduced by an order of magnitude, which is of great significance in practical applications. For example, it can improve experimental efficiency, reduce measurement costs, and obtain experimental results more quickly to guide subsequent work.

[0137] Furthermore, the single-photon detector performance parameter measurement method of the present application has technical advantages such as simplicity, high efficiency, and wide applicability. It does not require complicated operating steps and a large amount of manual intervention, can quickly obtain accurate measurement results, and greatly reduces the waiting time and resource consumption during the measurement process. Whether in basic physics experiments, materials science research, biomedical testing or other related fields, it has strong versatility and adaptability.

[0138] See also Figure 9A single-photon detector performance parameter measurement device provided to meet one of the purposes of this application includes a statistical histogram construction module 1100, a time domain range determination module 1200, a post-pulse probability determination module 1300, a dead time determination module 1400 and a time jitter determination module 1500. Among them, the statistical histogram construction module 1100 is configured to respond to the single-photon detector performance parameter measurement instruction, and use a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data; the time domain range determination module 1200 is configured to obtain the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram, determine the first time domain range corresponding to the photon event according to the first peak time, and use the time domain range exceeding the second peak time as the second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time; the post-pulse probability determination module 1300 is configured to calculate and determine the total photon event count value within the first time domain, and calculate and determine the second time domain A post-pulse event count value within a range is determined, and a post-pulse probability corresponding to each statistical sub-interval in the statistical histogram is determined according to the post-pulse event count value and the total photon event count value, and a post-pulse probability corresponding to the single-photon detector to be measured is determined according to the post-pulse probability corresponding to each statistical sub-interval; a dead time determination module 1400 is configured to calculate and determine a first difference between the second peak time and the first peak time to determine the dead time corresponding to the single-photon detector to be measured; a time jitter determination module 1500 is configured to calculate and determine the time jitter of the single-photon detector to be measured according to the half-width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the time-to-digital converter of the multi-event statistical histogram, so as to complete the measurement of the performance parameters of the single-photon detector.

[0139] Based on any embodiment of this application, please refer to Figure 10 Another embodiment of the present application further provides an electronic device, which can be implemented by a computer device, such as Figure 10As shown, a schematic diagram of the internal structure of a computer device. The computer device includes a processor, a computer-readable storage medium, a memory, and a network interface connected via a system bus. Among them, the computer-readable storage medium of the computer device stores an operating system, a database, and computer-readable instructions, and the database may store a control information sequence. When the computer-readable instructions are executed by the processor, the processor may implement a single-photon detector performance parameter measurement method. The processor of the computer device is used to provide computing and control capabilities to support the operation of the entire computer device. The memory of the computer device may store computer-readable instructions. When the computer-readable instructions are executed by the processor, the processor may execute the single-photon detector performance parameter measurement method of the present application. The network interface of the computer device is used to connect and communicate with a terminal. Those skilled in the art will understand that Figure 10 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0140] In this embodiment, the processor is used to execute Figure 9 The memory stores the program code and various data required to execute the specific functions of each module in the device. The network interface is used to transmit data between user terminals or servers. The memory in this embodiment stores the program code and data required to execute all modules / submodules in the single-photon detector performance parameter measurement device of this application. The server can call the server's program code and data to execute the functions of all submodules.

[0141] The present application also provides a storage medium storing computer-readable instructions. When the computer-readable instructions are executed by one or more processors, the one or more processors execute the steps of the single-photon detector performance parameter measurement method described in any embodiment of the present application.

[0142] The present application also provides a computer program product, including a computer program / instruction, which, when executed by one or more processors, implements the steps of the single-photon detector performance parameter measurement method described in any embodiment of the present application.

[0143] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments of the present application can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments of the method. The aforementioned storage medium can be a computer-readable storage medium such as a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0144] The above description is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

[0145] In summary, the single-photon detector performance parameter measurement method of the present application has technical advantages such as simplicity, high efficiency, and wide applicability. It does not require complicated operating steps and a large amount of manual intervention, can quickly obtain accurate measurement results, and greatly reduces the waiting time and resource consumption during the measurement process. Whether in basic physics experiments, materials science research, biomedical testing or other related fields, it has strong versatility and adaptability.

Claims

1. A method for measuring performance parameters of a single-photon detector, characterized in that: include: In response to a single-photon detector performance parameter measurement instruction, a multi-event statistical histogram time-to-digital converter is used to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured, so as to generate a statistical histogram of the time interval data; Obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determining a first time domain range corresponding to the photon event based on the first peak time, and using a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time; Calculate and determine the total photon event count value within the first time domain range, calculate and determine the afterpulse event count value within the second time domain range, determine the afterpulse probability corresponding to each statistical subinterval in the statistical histogram based on the afterpulse event count value and the total photon event count value, and determine the afterpulse probability corresponding to the single-photon detector to be measured based on the afterpulse probability corresponding to each statistical subinterval; Calculating and determining a first difference between the second peak time and the first peak time to determine a dead time corresponding to the single-photon detector to be measured; The time jitter of the single-photon detector to be measured is calculated and determined based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter to complete the measurement of the single-photon detector performance parameters.

2. The method for measuring the performance parameters of a single-photon detector according to claim 1, wherein: Before the step of using a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data, the method includes: The trigger signal generator module outputs two synchronous pulses, wherein one synchronous pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronous pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box through the optical fiber. The light output from the optical fiber is first collimated by a collimator, then attenuated by an adjustable attenuation plate, and then focused by an objective lens to the center of the photosensitive surface of the single-photon detector to be measured, so as to output the end pulse of the multi-event statistical histogram time-to-digital converter.

3. The method for measuring performance parameters of a single-photon detector according to claim 1, wherein: The step of using a multi-event statistical histogram time-to-digital converter to capture the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured to generate a statistical histogram of the time interval data includes: The multi-event statistical histogram time-to-digital converter is used to record the time interval data between the start pulse and the end pulse corresponding to each photon event of the single-photon detector to be measured; Determine the time interval range corresponding to each statistical subinterval in the statistical histogram, and distribute the time interval data generated by the single-photon detector to be measured under the action of each photon event to the time interval range corresponding to each statistical subinterval to construct a statistical histogram of the time interval data, wherein the statistical subinterval represents the frequency or frequency of occurrence of each photon event within a certain time interval.

4. The method for measuring performance parameters of a single-photon detector according to claim 1, wherein: The step of obtaining a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram comprises: In response to an instruction to correct a dark count effect of a single-photon detector to be measured, obtaining an original photon event count value measured in each statistical subinterval in the statistical histogram, a dark count rate of the single-photon detector to be measured, a time interval length of the statistical subinterval, a repetition frequency of the laser pulse, and a total data acquisition time; Calculating and determining a first product among the dark count rate of the single-photon detector to be measured, the time interval length of the statistical subinterval, the repetition frequency of the laser pulse, and the total data acquisition time, and calculating and determining a second difference between the original photon event count value and the first product to determine a corrected photon event count value in each statistical subinterval in the statistical histogram; The time domain distribution of net photon events and post-pulse events is determined based on the corrected photon event count value in each statistical sub-interval in the statistical histogram, and peak search processing is performed based on the time domain distribution of the net photon events and post-pulse events to determine the first peak time corresponding to the photon event peak and the second peak time corresponding to the post-pulse event peak in each statistical sub-interval in the statistical histogram.

5. The method for measuring performance parameters of a single-photon detector according to claim 1, wherein: The steps of calculating and determining a total photon event count value within the first time domain range, calculating and determining a post-pulse event count value within the second time domain range, determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determining a post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical subinterval, include: Calculating and determining all photon event count values ​​within a first time domain corresponding to a photon event in each statistical subinterval in the statistical histogram to determine a total photon event count value within the first time domain of each statistical subinterval in the statistical histogram; Calculating and determining a post-pulse event count value within a second time domain range corresponding to a post-pulse event in each statistical subinterval in the statistical histogram, and determining a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on a first ratio between the post-pulse event count value and the total photon event count value; A first sum value between the after-pulse probabilities corresponding to each statistical subinterval in the statistical histogram is calculated to determine the after-pulse probability corresponding to the single-photon detector to be measured.

6. The method for measuring performance parameters of a single-photon detector according to claim 1, wherein: The step of calculating and determining the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter includes: Acquire the full width at half maximum of the photon event peak, the laser pulse width, the time jitter corresponding to the synchronization pulse, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter; Calculating and determining a first square value of the full width at half maximum of the photon event peak, a second square value of the laser pulse width, a third square value of the time jitter corresponding to the synchronization pulse, and a fourth square value of the time jitter corresponding to the multi-event statistical histogram time-to-digital converter; A second sum of the second square value, the third square value, and the fourth square value is calculated and determined, a third difference between the first square value and the second sum is calculated and determined, and the time jitter of the single-photon detector to be measured is determined according to the square root of the third difference.

7. The method for measuring performance parameters of a single-photon detector according to any one of claims 1 to 6, characterized in that: The amplitude of the photon event peak is higher than the amplitude of the post-pulse event, and the post-pulse event peak appears after the photon event peak; The full width at half maximum of the photon event peak represents the horizontal distance between the intersection of the curve and the baseline when the peak height of the photon event peak is half. The smaller the horizontal distance, the higher the time resolution of the system. The single-photon detector to be measured includes a photomultiplier tube or a single-photon avalanche diode; The single-photon detector performance parameters include the after-pulse probability, dead time and time jitter of the single-photon detector.

8. A single-photon detector performance parameter measurement device, characterized in that: include: a statistical histogram construction module, configured to respond to a single-photon detector performance parameter measurement instruction, and use a multi-event statistical histogram time-to-digital converter to capture time interval data between a start pulse and an end pulse corresponding to each photon event of the single-photon detector to be measured, so as to generate a statistical histogram of the time interval data; a time domain range determination module, configured to obtain a first peak time corresponding to a photon event peak and a second peak time corresponding to a post-pulse event peak in each statistical subinterval in the statistical histogram, determine a first time domain range corresponding to the photon event based on the first peak time, and use a time domain range exceeding the second peak time as a second time domain range corresponding to the post-pulse event, wherein the second peak time is greater than the first peak time; a post-pulse probability determination module, configured to calculate and determine a total photon event count value within the first time domain range, calculate and determine a post-pulse event count value within the second time domain range, determine a post-pulse probability corresponding to each statistical subinterval in the statistical histogram based on the post-pulse event count value and the total photon event count value, and determine a post-pulse probability corresponding to the single-photon detector to be measured based on the post-pulse probability corresponding to each statistical subinterval; a dead time determination module, configured to calculate and determine a first difference between the second peak time and the first peak time, so as to determine a dead time corresponding to the single-photon detector to be measured; The time jitter determination module is configured to calculate and determine the time jitter of the single-photon detector to be measured based on the full width at half maximum of the photon event peak, the laser pulse width corresponding to the laser pulse emitted by the ultrashort pulse laser module, the time jitter corresponding to the synchronization pulse output by the signal generator module, and the time jitter corresponding to the multi-event statistical histogram time-to-digital converter, so as to complete the measurement of the performance parameters of the single-photon detector.

9. An electronic device comprising a central processing unit and a memory, characterized in that: The central processing unit is configured to call and run a computer program stored in the memory to execute the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that It stores a computer program implemented according to the method described in any one of claims 1 to 7 in the form of computer-readable instructions, and when the computer program is called and executed by a computer, the steps included in the corresponding method are executed.

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