Method, device and equipment for measuring performance parameters of single-photon detector and medium

Abstract

The invention relates to a single-photon detector performance parameter measurement method, device, equipment and medium, and relates to the technical field of single-photon detection.The method comprises the steps that a total photon event count value in a first time domain range is calculated and determined, a post-pulse event count value in a second time domain range is calculated and determined, and the post-pulse event count value is calculated and determined; determining the post-pulse probability of each statistical subinterval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determining the post-pulse probability of the to-be-measured single-photon detector according to the post-pulse probability of each statistical subinterval; calculating and determining a first difference value between the second peak time and the first peak time so as to determine the dead time of the to-be-measured single-photon detector; and calculating and determining the time jitter of the to-be-measured single-photon detector according to the pulse width of the laser pulse, the time jitter of the synchronous pulse and the time jitter of the multi-event statistical histogram hour-to-digital converter. The time for measuring the performance parameters of the single-photon detector is greatly shortened.

Description

Technical Field

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

[0002] Single-photon detectors play a key role in more and more cutting-edge photon counting and photon timing applications, including but not limited to quantum communication, light detection and ranging (LiDAR), fluorescence lifetime imaging, etc. In photon counting applications, single-photon detectors are combined with counters to record the number of incident photons in real time. However, due to the afterpulse and dead time effects of single-photon detectors, the actual measured count value always deviates from the true number of photons. In order to eliminate the counting distortion caused by afterpulses and dead time, accurate afterpulse probability and dead time values ​​are required to correct these two effects. In photon timing applications, single-photon detectors are combined with time-correlated single-photon counting (TCSPC) hardware to repeatedly record the arrival time of photons, and further reconstruct the time-domain intensity distribution of extremely weak incident light pulses through the statistical histogram of photon arrival time. The time resolution of the signal measured by this method is mainly determined by the time jitter of the single-photon detector. Therefore, accurate and reliable characterization of the afterpulse probability, dead time and time jitter of the single-photon detector is a key prerequisite for ensuring its photon counting and photon timing accuracy.

[0003] Afterpulse refers to the phenomenon that 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 afterpulse generation 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 afterpulse: 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 afterpulse 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 method, while its time jitter is often characterized using the TCSPC method. Using the above three independent methods to measure the post-pulse probability, dead time and time jitter of a single-photon detector in turn will not only greatly increase the measurement time and complexity, but will also greatly reduce the efficiency of the instrument.

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

[0005] The purpose of the present application is to solve the above-mentioned problems and to 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 single photon detector performance parameter measurement method 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 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, 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 according to 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 post-pulse event count value within the second time domain range, determine the post-pulse probability corresponding to each statistical sub-interval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determine the post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical sub-interval;

[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 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 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 step includes:

[0014] The trigger signal generator module outputs two synchronization pulses, wherein one synchronization pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronization pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box via 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 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:

[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 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.

[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] Calculate and determine 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 calculate and determine 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 values ​​in each statistical sub-interval in the statistical histogram, and peak searching is performed based on the time domain distribution of the net photon events and post-pulse events to determine a first peak time corresponding to a photon event peak in each statistical sub-interval in the statistical histogram and a second peak time corresponding to a post-pulse event peak.

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

[0023] 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;

[0024] 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;

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

[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 points 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 system time resolution.

[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 is 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 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, 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 of the statistical histogram, determine a first time domain range corresponding to the photon event according to 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 the total photon event count value within the first time domain range, calculate and determine the post-pulse event count value within the second time domain range, determine the post-pulse probability corresponding to each statistical sub-interval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determine the post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical sub-interval;

[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 half-width 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 prior art, the present application uses separate methods to measure the post-pulse probability, dead time and time jitter of a single-photon detector respectively, which not only greatly increases the measurement time and complexity, but also greatly reduces the efficiency of the instrument. The present application includes 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 at the same time, and can independently detect and record photon events and post-pulse events in the same time period. When a photon event is detected, the working mechanism of the system will not change the probability of the post-pulse event being detected 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 post-pulse event, making the measured post-pulse probability more accurate and reliable, and can truly reflect the actual situation of the post-pulse event;

[0045] Third, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has ultra-high time resolution, which enables it to accurately record the time when the event occurs. During the measurement process, the accurate recording of the time information of photon events and related physical phenomena helps to more accurately analyze and understand the measurement results, thereby improving the accuracy of the measurement. Compared with traditional discrete methods, it can capture the details and time characteristics of the event more meticulously, reducing the errors caused by inaccurate time measurement.

[0046] Fourthly, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has an on-chip histogram statistical capability, and 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, which greatly improves 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 a large amount of data in a short time, shortening the measurement time to the order of minutes, greatly shortening the measurement time of single-photon detector performance parameters such as after-pulse 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, such as improving experimental efficiency, reducing measurement costs, and obtaining experimental results faster 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 This is a flow chart of a method for measuring 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 a single-photon detector performance parameter measurement system in an embodiment of the present application;

[0053] Figure 4 A schematic diagram of the timing of simultaneously measuring the pulse probability, dead time and time jitter of a single-photon detector in an embodiment of the present application;

[0054] Figure 5 A schematic diagram of a process for determining a first peak time of a photon event peak and a 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 the embodiments of the present application;

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

[0057] Figure 8 A 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] Fig. 9 This is a principle block diagram of a single-photon detector performance parameter measurement device in an embodiment of the present application;

[0059] Fig.10 It is a 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 attenuation plate, 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 embodiments of the present application are described in detail below, and examples of the embodiments 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 cannot be interpreted as limiting the present application.

[0063] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include 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 an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit 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 those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

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

[0066] The hardware referred to by the names such as "server", "client", and "service node" in this application is essentially an electronic device with the equivalent capabilities of a personal computer. It is a hardware device with 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. The computer program is stored in its memory, and the central processing unit calls 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 pointed out that the concept of "server" referred to in this application can also be extended to the case of server clusters. According to the network deployment principle understood by those skilled in the art, the servers should be logically divided. In physical space, these servers can be independent of each other but can be called through interfaces, or integrated into a physical computer or a set of computer clusters. Those skilled in the art should understand this flexibility, and should not use it to restrict 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 access.

[0069] The neural network models referenced or may be referenced in this application, unless expressly specified, can be deployed on a remote server and remotely called on the client, or can be deployed and directly called on a client with sufficient device capabilities. In some embodiments, when it runs on the client, its corresponding intelligence can 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 it is 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 the present application are described based on the same concept and thus present commonality to each other, unless otherwise specified, these methods can be independently executed. Similarly, for each embodiment disclosed in the present application, they are all proposed based on the same inventive concept, therefore, concepts with the same expression, and concepts that are appropriately changed for convenience despite different expressions, should be understood as equivalent.

[0072] Unless the mutually exclusive relationship between the embodiments to be disclosed in this application is explicitly stated, the relevant technical features involved in each embodiment can be cross-combined to flexibly construct a new embodiment, 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 solve certain deficiencies in the prior art. Those skilled in the art should be aware of this 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 the single-photon detector performance parameter measurement instruction, 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, so as to generate a statistical histogram of the time interval data;

[0075] The 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, so as 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 post-pulse probability, dead time and time jitter of the single-photon detector, etc.

[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 captured between events is much smaller than the dead time of the detector to be tested, that is, the event sampling rate of the multi-event statistical histogram time-to-digital converter (ME-HTDC) is high enough;

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

[0079] Thirdly, 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 irradiated to the central area of ​​the photosensitive surface of the single-photon detector to be measured after attenuation and focusing, the pulse output by the single-photon detector to be measured is used as the end pulse of the multi-event statistical histogram time-to-digital converter, and the synchronization pulse of the ultrashort laser pulse is used as the start pulse of the multi-event statistical histogram time-to-digital converter, and 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 the irradiation of ultrashort laser pulses, the statistical histogram (that is, the 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 after-pulse 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, so as 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 synchronization pulses, wherein one synchronization pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronization pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box via 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 collimator 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 dark box 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 ultra-short 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 ultra-short 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. The objective lens 113 focuses on the center of the photosensitive surface of the single-photon detector 121 to be measured, and the output of the single-photon detector 121 to be measured is connected to the terminal end of the multi-event statistical histogram time-to-digital converter 131 for measuring the event time domain probability distribution. The computer 151 is connected to the multi-event statistical histogram time-to-digital converter 131 to read and store the measurement results of the multi-event statistical histogram time-to-digital converter 131 and perform subsequent processing to calculate the performance parameters of the single-photon detector 121 to be measured, such as the post-pulse probability, dead time and time jitter of the single-photon detector. In addition, the computer 151 is also connected to the 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 light 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. 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 constitute a limitation on this 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, and the time resolution of the multi-event statistical histogram time-to-digital converter is 27ps and the dynamic range is 1000ns. Considering 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 of which is used to trigger the ultrashort pulse laser module 102 to emit laser pulses, and the other is used as the start 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 through the optical fiber 103, wherein the pulse duration of the laser pulse is 54ps, the laser wavelength is 774nm and the frequency is 1.0MHz; the light emitted from the end of the optical fiber 103 is first collimated by the collimator 111, and then attenuated by the adjustable attenuator 112, the light is attenuated to the single photon level, and is focused by the objective lens 113 to 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 end of the multi-event statistical histogram time-to-digital converter 131 for measuring the time domain probability distribution of the event; the computer 151 is connected to the multi-event statistical histogram time-to-digital converter 131, and is used to read and store the statistical histogram measured by the multi-event statistical histogram time-to-digital converter, and perform subsequent processing to calculate and display the performance parameters of the single-photon detector to be measured, such as after-pulse probability, dead time and time jitter.

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

[0095] The timing of the synchronous pulse, the 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, post-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, 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 according to the first peak time, and taking 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, so as to generate a statistical histogram of the time interval data, and then 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 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 half-height full width of the photon event peak represents the horizontal distance between the intersection points of the curve and the baseline when the peak height of the photon event peak is half, and 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 the dark count effect of the single-photon detector to be measured, obtaining the original photon event count value measured in each statistical subinterval in the statistical histogram, 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;

[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, and 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, determining the time domain distribution of net photon events and post-pulse events based on the corrected photon event count values ​​in each statistical sub-interval in the statistical histogram, and performing peak searching based on the time domain distribution of the net photon events and post-pulse events to determine a first peak time corresponding to a photon event peak in each statistical sub-interval in the statistical histogram and a second peak time corresponding to a post-pulse event peak.

[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 sub-interval in the statistical histogram, the dark count effect of the single-photon detector to be measured needs to be corrected 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 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 searching 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 in each statistical sub-interval in the statistical histogram and the second peak time corresponding to the post-pulse event peak.

[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 based on a 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 (44.5ns) measured by the traditional oscilloscope method; the time jitter of the silicon single-photon detector is 304ps, which is in good agreement with the time jitter (299ps) measured by the traditional TCSPC method. The consistency of the above experimental results shows that the performance parameters of the silicon single-photon detector are very stable and reliable in terms of time accuracy through the single-photon detector performance parameter measurement method of the present 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 ; Peak I has a higher amplitude and is caused by photon events, while Peak II has a much lower amplitude and is caused by post-pulse events, and t ≥ t pkII The distribution of represents the time domain distribution of the post-pulse occurrence, that is, the second time domain range corresponding to the post-pulse 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 post-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 post-pulse probability, dead time and time jitter of single-photon detectors.

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

[0110] Obtain 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 sub-interval in the statistical histogram, determine a first time domain range corresponding to the photon event according to the first peak time, take a time domain range exceeding the second peak time as a second time domain range corresponding to a post-pulse event, 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 sub-interval in the statistical histogram according to 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 according to the post-pulse probability corresponding to each statistical sub-interval;

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

[0112] Step S301, 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, so as to determine a total photon event count value within the first time domain of each statistical subinterval in the statistical histogram;

[0113] Step S302, 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;

[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 post-pulse 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 range corresponding to the post-pulse event in the i-th statistical subinterval in the statistical histogram; C ph Represents all photon event count values ​​within the first time domain range corresponding to the photon event in the i-th statistical subinterval in the statistical histogram.

[0119] Step S40, calculating and determining 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;

[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 according to 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 then 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] It can be seen from the above embodiments that a set of photon event data is collected through the single photon detector to be measured, each photon event corresponds to a timestamp, and these timestamps are distributed in the statistical histogram; all photon event data are arranged in chronological order, and the first photon event peak in each subinterval is identified according to the distribution of each subinterval in the statistical histogram, each photon event peak represents a local maximum value, and its corresponding time point is the first peak time; after the first peak time of the photon event, continue to search and identify the second peak of the post-pulse event, which usually appears a period of time after the first peak. Determine the time of the second peak and use it as the second peak time; starting from the first peak time, select an appropriate time domain range to define the time domain distribution of the photon event, which can be determined by setting a fixed time window or based on the intensity drop of the signal; after the second peak time, select a time domain range as the time domain of the post-pulse event; this time domain should ensure that all important signals of the post-pulse are covered. Calculate the time difference between the first peak time and the second peak time to obtain a first difference to determine the dead time corresponding to the single photon detector to be measured.

[0122] Step S50, 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 multi-event statistical histogram time-to-digital converter, calculate and determine the time jitter of the single-photon detector to be measured, so as to complete the measurement of the performance parameters of the single-photon detector.

[0123] After calculating and determining the 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 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 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 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 multi-event statistical histogram time-to-digital converter comprises:

[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 half-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 value of the third difference.

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

[0129]

[0130] Among them, σ m represents the half-height full width 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 Represents 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 prior art, the present application uses separate methods to measure the post-pulse probability, dead time and time jitter of a single-photon detector respectively, which not only greatly increases the measurement time and complexity, but also greatly reduces the efficiency of the instrument. The present application includes 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 at the same time, and can independently detect and record photon events and post-pulse events in the same time period. When a photon event is detected, the working mechanism of the system will not change the probability of the post-pulse event being detected 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 post-pulse event, making the measured post-pulse probability more accurate and reliable, and can truly reflect the actual situation of the post-pulse event;

[0134] Third, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has ultra-high time resolution, which enables it to accurately record the time when the event occurs. During the measurement process, the accurate recording of the time information of photon events and related physical phenomena helps to more accurately analyze and understand the measurement results, thereby improving the accuracy of the measurement. Compared with traditional discrete methods, it can capture the details and time characteristics of the event more meticulously, reducing the errors caused by inaccurate time measurement.

[0135] Fourthly, the single-photon detector performance parameter measurement method of the present application, the multi-event statistical histogram time-to-digital converter has an on-chip histogram statistical capability, and 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, which greatly improves 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 a large amount of data in a short time, shortening the measurement time to the order of minutes, greatly shortening the measurement time of single-photon detector performance parameters such as after-pulse 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, such as improving experimental efficiency, reducing measurement costs, and obtaining experimental results faster 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 Fig. 9A single-photon detector performance parameter measurement device provided to meet one of the purposes of the present 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, so as 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 range, and calculate and determine the second time domain A post-pulse event count value within a range, 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 Fig.10 Another embodiment of the present application further provides an electronic device, which can be implemented by a computer device, such as Fig.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. The database may store a control information sequence. When the computer-readable instructions are executed by the processor, the processor can 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 can 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 Fig.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 those shown in the figure, or combine certain components, or have a different arrangement of components.

[0140] In this embodiment, the processor is used to execute Fig. 9 The memory stores the program code and various data required to execute the above modules. 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 / sub-modules in the single-photon detector performance parameter measurement device of the present application, and the server can call the program code and data of the server to execute the functions of all sub-modules.

[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 can understand 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, and the computer program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the aforementioned storage medium can be a computer-readable storage medium such as a disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0144] The above description is only a partial implementation method 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 the technical advantages of 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 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, 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 according to 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 post-pulse event count value within the second time domain range, determine the post-pulse probability corresponding to each statistical sub-interval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determine the post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical sub-interval; 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 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 multi-event statistical histogram time-to-digital converter to complete the measurement of the single-photon detector performance parameters.

2. The method for measuring performance parameters of a single photon detector according to claim 1, characterized in that: 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 synchronization pulses, wherein one synchronization pulse serves as the start pulse of the multi-event statistical histogram time-to-digital converter, and the other synchronization pulse triggers the ultrashort pulse laser module to emit a laser pulse which is introduced into the dark box via 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 single photon detector performance parameter measurement method according to claim 1, characterized in that: 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 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.

4. The method for measuring performance parameters of a single photon detector according to claim 1, characterized in that: 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; Calculate and determine 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 calculate and determine 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 values ​​in each statistical sub-interval in the statistical histogram, and peak searching is performed based on the time domain distribution of the net photon events and post-pulse events to determine a first peak time corresponding to a photon event peak in each statistical sub-interval in the statistical histogram and a second peak time corresponding to a post-pulse event peak.

5. The method for measuring performance parameters of a single photon detector according to claim 1, characterized in that: The steps of calculating and determining the total photon event count value within the first time domain range, calculating and determining the post-pulse event count value within the second time domain range, determining the post-pulse probability corresponding to each statistical sub-interval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determining the post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical sub-interval, include: 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; 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; 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, characterized in that: The step of calculating and determining 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 multi-event statistical histogram time-to-digital converter comprises: 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; Calculate and determine a first square value of the half-width 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 value among the second square value, the third square value and the fourth square value is calculated and determined, a third difference value between the first square value and the second sum value is calculated and determined, and the time jitter of the single-photon detector to be measured is determined according to the square root value of the third difference value.

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 points 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 system time resolution. 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 is 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 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, 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 of the statistical histogram, determine a first time domain range corresponding to the photon event according to 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 the total photon event count value within the first time domain range, calculate and determine the post-pulse event count value within the second time domain range, determine the post-pulse probability corresponding to each statistical sub-interval in the statistical histogram according to the post-pulse event count value and the total photon event count value, and determine the post-pulse probability corresponding to the single-photon detector to be measured according to the post-pulse probability corresponding to each statistical sub-interval; 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 half-width 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 used to call and run the 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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