CN118776831B

CN118776831B - Method, device, equipment and medium for measuring detection efficiency of single photon detector

Info

Publication number: CN118776831B
Application number: CN202411266828.1A
Authority: CN
Inventors: 颜林; 唐嘉铭; 肖鹏; 马四光
Original assignee: Ji Hua Laboratory
Current assignee: Ji Hua Laboratory
Priority date: 2024-09-11
Filing date: 2024-09-11
Publication date: 2024-11-15
Anticipated expiration: 2044-09-11
Also published as: CN118776831A

Abstract

The present application relates to a method, device, equipment and medium for measuring the detection efficiency of a single-photon detector, which relates to the field of single-photon detection technology. The method includes: obtaining the time interval data generated by the single-photon detector to be measured in the event refresh time-to-digital converter under the action of each light pulse of the same wavelength, calculating and determining the probability density of the statistical subinterval of the statistical histogram that the time interval data falls into a preset statistical histogram, so as to determine the time-domain photon probability distribution of the single-photon detector to be measured under the irradiation of each light pulse; fitting the time-domain photon probability distribution using a preset photoelectron counting model to determine the average number of photoelectrons detected by the single-photon detector to be measured under the action of a single light pulse; determining the detection efficiency of the single-photon detector to be measured based on the average number of incident photons and the average number of photoelectrons, so as to complete the measurement of the detection efficiency of the single-photon detector. The present application greatly improves the measurement efficiency while significantly improving the measurement accuracy of the detection efficiency spectrum.

Description

Method, device, equipment and medium for measuring detection efficiency of single photon detector

Technical Field

The present application relates to the field of single photon detection technology, and in particular, to a method for measuring detection efficiency of a single photon detector, a corresponding device, an electronic apparatus, and a computer readable storage medium.

Background

The single photon detector has important characteristics such as single photon response sensitivity and picosecond time resolution, and is widely applied to the fields of front-edge science and technology such as quantum information, laser radar, fluorescence analysis and the like. Different application scenarios have different requirements for the performance of single photon detectors. Accurate and reliable measurement of performance parameters of single photon detectors is a precondition for selection of an appropriate single photon detector for a particular application. The detection efficiency is the most core performance parameter of the single photon detector and is used for representing the capability of the single photon detector to convert the number of incident photons into the number of detectable electric pulses.

At present, the measuring method of the single photon detector detection efficiency mainly comprises a related photon method and a standard detector method, wherein the related photon method and the standard detector method both adopt a counter to measure the output pulse rate of the single photon detector under the illumination condition and calculate the detection efficiency according to the output pulse rate, however, the actually measured count comprises dark pulse and post pulse count besides the count caused by photons due to non-ideal characteristics such as dark count, post pulse and the like of the single photon detector. Furthermore, single photon detectors have dead time effects, resulting in actual measured count rates that are less than the actual photon count rates. To obtain a true photon count rate, dark count, post-pulse and dead time corrections are required for the actual measured count rate, which means that additional measurements of the dark count rate, post-pulse probability, dead time of the single photon detector and accurate correction models are required, which not only greatly increase the complexity of the detection efficiency measurement, but also introduce additional measurement errors.

In summary, in order to obtain the actual photon counting rate, the measuring method of the single photon detector adapted to the prior art needs to perform dark counting, post-pulse and dead time correction on the actually measured counting rate, and these additional measurements and corrections not only greatly increase the complexity of measuring the detecting efficiency, but also introduce additional measurement errors.

Disclosure of Invention

The present application is directed to a method for measuring the detection efficiency of a single photon detector, a corresponding apparatus, an electronic device and a computer readable storage medium.

In order to meet the purposes of the application, the application adopts the following technical scheme:

a method for measuring detection efficiency of a single photon detector according to one of the objects of the present application comprises:

responding to a detection efficiency measurement instruction of a single photon detector, and obtaining the optical power of a first calibration photodiode and a second calibration photodiode under the irradiation of each single-color light-emitting diode in the single-color light-emitting diode array in the calibration measurement process so as to determine the calibration coefficient of each single-color light-emitting diode;

Calculating and determining the average incident photon number of each single-color light emitting diode irradiated on the photosensitive area of the single-photon detector to be measured according to the calibration coefficient, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured;

Acquiring time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in an event refreshing time-to-number converter, and calculating and determining probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram so as to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse;

fitting the time domain photon probability distribution by adopting a preset photoelectron counting model to determine the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse;

And determining the detection efficiency of the single photon detector to be measured based on the average incident photon number and the average photoelectron number so as to finish the measurement of the detection efficiency of the single photon detector.

Optionally, the step of obtaining the optical power of the first calibration photodiode and the second calibration photodiode under the irradiation of each of the single-color light emitting diodes in the single-color light emitting diode array during the calibration measurement process to determine the calibration coefficient of each single-color light emitting diode includes:

determining the optical power of a first calibration photodiode and a second calibration photodiode in a calibration measurement process under the irradiation of each single-color light emitting diode in the single-color light emitting diode array;

a scaling factor for each monochromatic light emitting diode is determined based on a ratio between the optical power of the second calibration photodiode and the optical power of the first calibration photodiode.

Optionally, the step of calculating and determining the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured according to the scaling factor, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode, and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured includes:

acquiring the photosensitive area of the single photon detector to be measured, the photosensitive area of the second calibration photodiode, the calibration coefficient of each single-color light emitting diode, the optical power of the first calibration photodiode, the center wavelength emitted by each single-color light emitting diode and the frequency of the light pulse emitted by each single-color light emitting diode in the detection efficiency measurement process of the single photon detector to be measured;

Calculating and determining a first ratio between the center wavelength emitted by each single-color light emitting diode and the frequency of the light pulses emitted by each single-color light emitting diode;

Calculating and determining a second ratio between the photosensitive area of the single photon detector to be measured and the photosensitive area of the second calibration photodiode;

calculating and determining a first product of a scaling coefficient of each monochromatic light emitting diode and the optical power of a first calibration photodiode in the detection efficiency measurement process of the single photon detector to be measured;

and calculating and determining the average incident photon number of each single-color light emitting diode irradiated on the photosensitive area of the single-photon detector to be measured based on the first ratio, the second ratio and the first product.

Optionally, the step of obtaining time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in the event refreshing time-to-digital converter, calculating and determining probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse includes:

recording time interval data generated by the single photon detector to be measured under the action of each light pulse by adopting an event refreshing time-to-digital converter;

determining the width of each statistical subinterval of the statistical histogram, wherein each statistical subinterval represents a time interval range, and the width of each statistical subinterval is larger than the width of each single-color light-emitting diode emission pulse;

Distributing time interval data generated by the single photon detector to be measured under the action of each light pulse to each statistical subinterval to construct a statistical histogram;

determining the total event in the statistical histogram and the count of the time interval range of each statistical subinterval, and obtaining the probability density of the time interval range of each statistical subinterval based on the ratio between the count of the time interval range of each statistical subinterval and the total event in the statistical histogram so as to determine the time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse.

Optionally, the photoelectron counting model is:

，

Wherein j represents the jth statistical subinterval of the statistical histogram; representing the probability that a single photon detector will not detect a dark pulse within the time interval of each statistical subinterval, Representing the dark pulse count rate, Δt representing the time interval range for each statistical subinterval; the probability that the single photon detector cannot detect the pulse and the dark pulse caused by photons at the same time in the time interval range of each statistical subinterval is represented, and mu represents the average photoelectron number detected by the single photon detector under the action of a single light pulse; Representing a number of statistical subintervals contained within a delay time between a start pulse of the digitizer and the light pulse at the event refresh time; m represents the mth photon probability peak in the statistical histogram; n represents a period of The number of statistical subintervals contained between photon probability peaks; Representing a time-domain photon probability distribution.

Optionally, the step of determining the detection efficiency of the single photon detector to be measured based on the average incident photon number and the average photoelectron number includes:

determining the average incident photon number of each monochromatic light emitting diode irradiated to a photosensitive area of a single photon detector to be measured, and the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse;

And determining the detection efficiency of the single photon detector to be measured based on the ratio of the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse to the average incident photon number irradiated by each single-color light emitting diode on the photosensitive area of the single photon detector to be measured.

Optionally, the photosensitive area of the second calibration photodiode is located at the same position as the photosensitive area of the single-photon detector to be measured, the wavelength of each single-color light emitting diode in the single-color light emitting diode array is different, and the single-photon detector to be measured comprises a photomultiplier tube or a single-photon avalanche diode.

A single photon detector detection efficiency measuring apparatus adapted to another object of the present application includes:

The calibration coefficient determining module is used for responding to the detection efficiency measuring instruction of the single photon detector, obtaining the optical power of the first calibration photodiode and the second calibration photodiode under the irradiation of each single-color light-emitting diode in the single-color light-emitting diode array in the calibration measuring process, and determining the calibration coefficient of each single-color light-emitting diode;

The incident photon number determining module is configured to calculate and determine the average incident photon number of each single-color light emitting diode irradiated on the photosensitive area of the single-photon detector to be measured according to the scaling coefficient, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode and the optical power of the first calibration photodiode in the detection efficiency measuring process of the single-photon detector to be measured;

The probability distribution determining module is used for obtaining time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in the event refreshing time-to-digital converter, calculating and determining probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram so as to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse;

The photoelectron number determining module is used for fitting the time domain photon probability distribution by adopting a preset photoelectron counting model so as to determine the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse;

and the detection efficiency determining module is used for determining the detection efficiency of the single photon detector to be measured based on the average incident photon number and the average photoelectron number so as to finish the measurement of the detection efficiency of the single photon detector.

An electronic device adapted for another object of the application comprises a central processor and a memory, said central processor being adapted to invoke the execution of a computer program stored in said memory for performing the steps of the method for measuring the detection efficiency of a single photon detector according to the application.

A computer-readable storage medium adapted to another object of the present application stores, in the form of computer-readable instructions, a computer program implemented according to the single photon detector detection efficiency measurement method, which when invoked by a computer, performs the steps comprised by the corresponding method.

Compared with the prior art, the application aims at the problems that in order to obtain the real photon counting rate, the actual counting rate needs to be subjected to dark counting, post pulse and dead time correction, the additional measurement and correction not only greatly increase the complexity of the detection efficiency measurement, but also can introduce additional measurement errors and the like, and the application comprises the following beneficial effects:

Firstly, the event refresh time-to-digital converter only measures the arrival time of a first event (namely an end pulse) after a start pulse, and the start pulse and the end pulse of the event refresh time-to-digital converter are respectively a synchronous pulse of a light source and a pulse output by a single photon detector, and in the measurement mode, the dead time of the single photon detector cannot influence the detection probability of the first event;

Secondly, the optical pulse period is far longer than the duration of the rear pulse probability of the single photon detector, so that the probability of a rear pulse event occurring in the optical pulse duration is ensured to be zero;

Thirdly, fitting the time domain probability distribution measured by the event refreshing time-to-number converter by using the established photoelectron counting model, and simultaneously obtaining the average photoelectron number and the dark counting rate, wherein the dark counting effect of the single photon detector is not required to be measured and corrected in advance;

Furthermore, the method for measuring the detection efficiency of the single photon detector provided by the application can rapidly and accurately measure the detection efficiency spectrum of the single photon detector in a wide spectrum range, does not need to additionally measure and correct the dead time, the dark counting rate and the post-pulse probability of the single photon detector, greatly reduces the data quantity required to be directly measured, avoids introducing additional measurement errors, greatly improves the measurement efficiency and simultaneously remarkably improves the measurement precision of the detection efficiency spectrum.

Drawings

The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exemplary network architecture employed by a single photon detector detection efficiency measurement system of the present application;

FIG. 2 is a schematic diagram of a timing sequence for measuring a detection efficiency of a single photon detector based on an event refresh time-to-digital converter according to an embodiment of the present application;

FIG. 3 is a flow chart of a method for measuring the detection efficiency of a single photon detector according to an embodiment of the application;

FIG. 4 is a flow chart of determining the scaling factor for each single color LED according to an embodiment of the present application;

FIG. 5 is a schematic flow chart of determining the average incident photon number of each single-color LED irradiated on the photosensitive area of the single-photon detector to be measured according to the embodiment of the application;

FIG. 6 is a schematic flow chart of determining a time-domain photon probability distribution of a single photon detector to be measured under irradiation of each light pulse in an embodiment of the application;

FIG. 7 is a schematic diagram of a time domain probability distribution of a silicon single photon avalanche diode under 670 nm monochromatic LED pulsed light irradiation in an embodiment of the present application;

FIG. 8 is a flow chart of determining the detection efficiency of a single photon detector to be measured in an embodiment of the application;

FIG. 9 is a schematic block diagram of a single photon detector detection efficiency measurement device in accordance with an embodiment of the present application;

fig. 10 is a schematic structural diagram of a computer device according to an embodiment of the present application.

Reference numerals:

The device comprises a 101 pulse generator module, a 102 programmable switch selection circuit module, a 103 monochromatic light emitting diode array, a 111 integrating sphere, a 121 single photon detector to be measured, a 122 voltage source, a 131 first calibration photodiode, a 132 power meter, a 141 event refreshing time-to-digital converter module, a 151 computer terminal device and a 161 camera bellows.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. The term "and/or" as used herein includes all or any element and all combination of one or more of the associated listed items.

It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, "client," "terminal device," and "terminal device" are understood by those skilled in the art to include both devices that include only wireless signal receivers without transmitting capabilities and devices that include receiving and transmitting hardware capable of two-way communication over a two-way communication link. Such a device may include: a cellular or other communication device such as a personal computer, tablet, or the like, having a single-line display or a multi-line display or a cellular or other communication device without a multi-line display; PCS (Personal Communications Service, personal communications System) that may combine voice, data processing, facsimile and/or data communications capabilities; PDA (Personal DIGITAL ASSISTANT ) that may include a radio frequency receiver, pager, internet/intranet access, web browser, notepad, calendar and/or GPS (Global Positioning System ) receiver; a conventional laptop and/or palmtop computer or other appliance that has and/or includes a radio frequency receiver. As used herein, "client," "terminal device" may be portable, transportable, installed in a vehicle (aeronautical, maritime, and/or land-based), or adapted and/or configured to operate locally and/or in a distributed fashion, at any other location(s) on earth and/or in space. As used herein, a "client," "terminal device," or "terminal device" may also be a communication terminal, an internet terminal, or a music/video playing terminal, for example, may be a PDA, a MID (Mobile INTERNET DEVICE ), and/or a Mobile phone with a music/video playing function, or may also be a device such as a smart tv, a set top box, or the like.

The application refers to hardware such as a server, a client, a service node, and the like, which essentially is an electronic device with personal computer and other functions, and is a hardware device with necessary components disclosed by von neumann principles such as a central processing unit (including an arithmetic unit and a controller), a memory, an input device, an output device, and the like, wherein a computer program is stored in the memory, and the central processing unit calls the program stored in the memory to run, executes instructions in the program, and interacts with the input and output devices, thereby completing specific functions.

It should be noted that the concept of the present application, called "server", is equally applicable to the case of server clusters. The servers should be logically partitioned, physically separate from each other but interface-callable, or integrated into a physical computer or group of computers, according to network deployment principles understood by those skilled in the art. Those skilled in the art will appreciate this variation and should not be construed as limiting the implementation of the network deployment approach of the present application.

One or more technical features of the present application, unless specified in the clear, may be deployed either on a server for implementation and the client remotely invokes an online service interface provided by the acquisition server for implementation of the access, or may be deployed and run directly on the client for implementation of the access.

The neural network model cited or possibly cited in the application can be deployed on a remote server and can be used for implementing remote call on a client, or can be deployed on a client with sufficient equipment capability for direct call, unless specified by plaintext, and in some embodiments, when the neural network model runs on the client, the corresponding intelligence can be obtained through migration learning so as to reduce the requirement on the running resources of the hardware of the client and avoid excessively occupying the running resources of the hardware of the client.

The various data related to the present application, unless specified in the plain text, may be stored either remotely in a server or in a local terminal device, as long as it is suitable for being invoked by the technical solution of the present application.

Those skilled in the art will appreciate that: although the various methods of the present application are described based on the same concepts so as to be common to each other, the methods may be performed independently of each other unless specifically indicated otherwise. Similarly, for the various embodiments disclosed herein, all concepts described herein are presented based on the same general inventive concept, and thus, concepts described herein with respect to the same general inventive concept, and concepts that are merely convenient and appropriately modified, although different, should be interpreted as equivalents.

The various embodiments of the present application to be disclosed herein, unless the plain text indicates a mutually exclusive relationship with each other, the technical features related to the various embodiments may be cross-combined to flexibly construct a new embodiment as long as such combination does not depart from the inventive spirit of the present application and can satisfy the needs in the art or solve the deficiencies in the prior art. This variant will be known to the person skilled in the art.

Referring to fig. 1, the method for measuring the detection efficiency of a single photon detector according to the present application may be implemented based on a single photon detector detection efficiency measuring system of an event refresh time-to-digital converter, which includes a pulse generator module 101, a single color light emitting diode programmable switch selection circuit module 102, a single color Light Emitting Diode (LED) array 103, an integrating sphere 111, a single photon detector 121 to be measured, a voltage source 122, a first calibration photodiode 131, a power meter 132, an event refresh time-to-digital converter (TDC) module 141, a computer terminal device 151, and a camera bellows 161, wherein a solid line with a unidirectional arrow indicates a light propagation path, and a solid line indicates an electrical connection.

In some embodiments, the single photon detector 121 to be measured includes, but is not limited to, a photomultiplier tube or a single photon avalanche diode including silicon (Si) single photon avalanche diode, indium gallium arsenide (InGaAs) single photon avalanche diode, and the like. Silicon (Si) single photon avalanche diodes are chosen as illustration. Whereas the spectral region of the silicon (Si) single photon avalanche diode response covers the visible and near infrared region, 16 monochromatic Light Emitting Diodes (LEDs) with a selected wavelength range covering 400-1000 nm are integrated together to form a 4' 4 array of LEDs.

In some embodiments, the frequency, pulse width, and high level values of the pulses output by the pulse generator module 101 are controlled and adjusted by an automated test program running in the computer terminal 151 to effect adjustment of the light emitting intensity of the single color light emitting diodes. The period of the pulse generator module 101 output pulse is longer than the duration of the single photon detector post-pulse probability to be measured (typically within 5 ms) to eliminate the effect of the single photon detector post-pulse, but this limits the maximum applicable pulse frequency.

In some embodiments, the array 103 of monochromatic light emitting diodes comprises a plurality of monochromatic Light Emitting Diodes (LEDs) of different wavelengths, the size of the array and the emission wavelength of the monochromatic light emitting diodes therein being selected according to the spectral range to be measured by the single photon detector. Different spatial positions in the single-color light-emitting diode array correspond to different single-color light-emitting diode emission wavelengths, and the programmable switch selection circuit module 102 is controlled by an automatic test program to selectively send driving pulses input by the pulse generator module 101 to the single-color light-emitting diodes with a certain wavelength in the single-color light-emitting diode array, so that the selection of the single-color light-emitting diode wavelength is realized. The programmable switch selection circuit module 102 combines the monochromatic light emitting diode array 103 to realize a monochromatic pulsed light source with adjustable wavelength in a wide spectral range.

In some embodiments, the pulse generator module 101 is controlled by an automated test program running in the computer terminal 151 to output two synchronous square wave pulses of a specific frequency, which may be 200 kHz, and a pulse width, which may be 20 ns, one of which is selectively sent to a single color Light Emitting Diode (LED) of a certain wavelength in the single color Light Emitting Diode (LED) array 103 via the single color light emitting diode programmable switch selection circuit module 102 for driving the single color Light Emitting Diode (LED) to emit a light pulse, and the other of which is input to the beginning of the event refresh time digitizer module 141, wherein the certain wavelength may be 670 nm.

Pulsed light emitted by a single-color Light Emitting Diode (LED) enters the integrating sphere through the inlet of the integrating sphere 111, and is respectively emitted from the horizontal opening and the vertical opening of the integrating sphere after being homogenized. The light power emitted from the vertical opening of the integrating sphere 111 is monitored by adopting the first calibration photodiode 131 and the power meter 132, and the light emitted from the horizontal opening of the integrating sphere directly irradiates the photosensitive surface of the single photon detector 121 to be measured, and the single photon detector 121 to be measured is powered by the voltage source 122; the output of the single photon detector 121 to be measured is connected to the end of the event refresh time digital converter module 141 to measure the time interval between the output pulse of the single photon detector to be measured and the driving pulse of the single color Light Emitting Diode (LED), the corresponding measurement time sequence is shown in fig. 2, and the automatic test program synchronously records the power measured by the optical power meter 132 and the time interval measured by the event refresh time digital converter module 141 in the set acquisition time.

When the data collection at a certain wavelength is completed, the automatic test program running in the computer terminal device 151 controls the monochromatic Light Emitting Diode (LED) switch selection circuit module 102 to switch the driving pulse generated by the pulse generator module 101 to the monochromatic Light Emitting Diode (LED) at another wavelength, and the automatic test program records the data measured by the optical power meter 132 and the event refresh time-to-event converter module 141 synchronously within the set collection time, and repeats the process until the measurement of the monochromatic Light Emitting Diodes (LEDs) at all wavelengths in the monochromatic Light Emitting Diode (LED) array 103 is completed.

In some embodiments, referring to fig. 2, the timing of measuring the detection efficiency of the single photon detector based on the event refresh time digitizer is shown in fig. 2, where the driving pulse of the single color Light Emitting Diode (LED) and the start pulse 21 of the event refresh time digitizer module, the light pulse 22 emitted by the single color Light Emitting Diode (LED), the pulse 23 output by the single photon detector are used as the end pulse of the event refresh time digitizer module, the time interval 24 between the start pulse and the end pulse measured by the event refresh time digitizer is the time interval between the first event when the event refresh time digitizer only measures the first event when the event refresh time digitizer encounters the end after the start end is started, and if no event is encountered at the end within the maximum measurable time range of the event refresh time digitizer, the measurement is forcedly ended, and the next measurement is started.

With reference to the above exemplary scenario and referring to fig. 3, in one embodiment, the method for measuring the detection efficiency of the single photon detector of the present application includes:

step S10, responding to a detection efficiency measurement instruction of a single photon detector, and obtaining the light power of a first calibration photodiode and a second calibration photodiode under the irradiation of each single-color light-emitting diode in the single-color light-emitting diode array in the calibration measurement process so as to determine the calibration coefficient of each single-color light-emitting diode;

The computer terminal 151 in the single photon detector detection efficiency measurement system may respond to a single photon detector detection efficiency measurement instruction, and obtain the optical power of the first calibration photodiode 131 and the second calibration photodiode under irradiation of each single photon light emitting diode in the single photon light emitting diode array 103 in the calibration measurement process, so as to determine the calibration coefficient of each single photon light emitting diode, where the photosensitive area of the second calibration photodiode is located at the same position as the photosensitive area of the single photon detector to be measured, and the wavelength of each single photon light emitting diode in the single photon light emitting diode array is different, where the single photon detector to be measured includes a photomultiplier tube or a single photon avalanche diode, and the single photon avalanche diode includes a silicon (Si) single photon avalanche diode, an indium gallium arsenide (InGaAs) single photon avalanche diode, and so on.

Further, referring to fig. 4, the step of obtaining the optical power of the first calibration photodiode and the second calibration photodiode irradiated by each of the single-color light emitting diodes in the array of single-color light emitting diodes in the calibration measurement process to determine the calibration coefficient of each single-color light emitting diode includes:

Step S101, under the irradiation of each single-color light emitting diode in the single-color light emitting diode array, determining the optical power of a first calibration photodiode and a second calibration photodiode in the calibration measurement process;

step S102, determining a scaling factor of each monochromatic light emitting diode based on the ratio between the optical power of the second calibration photodiode and the optical power of the first calibration photodiode.

Specifically, to accurately obtain the average number of photons incident on the photosensitive surface of the single photon detector to be measured, the reference detector (i.e., the first calibration photodiode 131) and the optical power at the position of the single photon detector to be measured in fig. 1 need to be calibrated, the first calibration photodiode 131 is kept unchanged, the single photon detector to be measured is replaced by the second calibration photodiode, the photosensitive surface of the single photon detector to be measured and the photosensitive surface of the second calibration photodiode are kept at the same position, and the optical power of each of the first calibration photodiode 131 and the second calibration photodiode irradiated by each of the single-color Light Emitting Diodes (LEDs) in the array of single-color Light Emitting Diodes (LEDs) is sequentially measured, so as to obtain the calibration coefficient of each single-color Light Emitting Diode (LED), and the calibration coefficient of each single-color Light Emitting Diode (LED) is determined according to the ratio of the powers measured by the second calibration photodiode and the first calibration photodiode 131 in the calibration measurement process.

Scaling factor for each single color Light Emitting Diode (LED)The calculation formula of (2) is as follows:

，

wherein, Representing the scaling factor for each single color Light Emitting Diode (LED),For the power measured by the second calibration photodiode during the calibration measurement,For the power measured by the first calibration photodiode during the calibration measurement,For each monochromatic light emitting diode.

In some embodiments, the steps and flow of performing a scaled measurement of the optical power at the first calibrated photodiode 131 and the single photon detector location to be measured as shown in fig. 1 are as follows: keeping the first calibration photodiode 131 unchanged, replacing the single photon detector to be measured with a second calibration photodiode (not shown in fig. 1), keeping the photosensitive surface of the single photon detector and the photosensitive surface of the second calibration photodiode at the same position, controlling the monochromatic Light Emitting Diode (LED) switch selection circuit module 102 by using an automatic test program in the computing terminal equipment, sequentially loading the driving pulse generated by the pulse generator module 101 onto each monochromatic Light Emitting Diode (LED) in the monochromatic Light Emitting Diode (LED) array in time sequence, and synchronously recording the optical powers measured by the two calibration photodiodes by the automatic test program in the time of each monochromatic Light Emitting Diode (LED) to emit light according to the calibration coefficientAutomatically calculating the calibration coefficient of each single-color Light Emitting Diode (LED)And stored.

Step S20, calculating and determining the average incident photon number of each single-color light emitting diode irradiated on the photosensitive area of the single-photon detector to be measured according to the calibration coefficient, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured;

After determining the calibration coefficient of each single-color light emitting diode, calculating and determining the average incident photon number of each single-color light emitting diode irradiated on the photosensitive area of the single-photon detector to be measured according to the calibration coefficient, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured;

Further, referring to fig. 5, the step of calculating and determining the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured according to the scaling factor, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode, and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured includes:

Step S201, acquiring the photosensitive area of the single photon detector to be measured, the photosensitive area of the second calibration photodiode, the calibration coefficient of each single color light emitting diode, the optical power of the first calibration photodiode, the center wavelength emitted by each single color light emitting diode and the frequency of the light pulse emitted by each single color light emitting diode in the detection efficiency measurement process of the single photon detector to be measured;

Step S202, calculating and determining a first ratio between the central wavelength emitted by each single-color light emitting diode and the frequency of the light pulse emitted by each single-color light emitting diode;

step S203, calculating and determining a second ratio between the photosensitive area of the single photon detector to be measured and the photosensitive area of the second calibration photodiode;

Step S204, calculating and determining a first product of a scaling coefficient of each monochromatic light emitting diode and the optical power of a first calibration photodiode in the detection efficiency measurement process of the single photon detector to be measured;

step S205, calculating and determining the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured based on the first ratio, the second ratio and the first product.

Specifically, the computer terminal device 151 in the single photon detector detection efficiency measurement system obtains the photosensitive area of the single photon detector to be measured, the photosensitive area of the second calibration photodiode, the calibration coefficient of each single color light emitting diode, the optical power of the first calibration photodiode, the center wavelength emitted by each single color light emitting diode and the frequency of the light pulse emitted by each single color light emitting diode in the detection efficiency measurement process of the single photon detector to be measured, and determines the planckian constant and the speed of light in vacuum; first calculating and determining a first ratio between the central wavelength emitted by each single-color light emitting diode and the frequency of the light pulse emitted by each single-color light emitting diode; calculating and determining a second ratio between the photosensitive area of the single photon detector to be measured and the photosensitive area of the second calibration photodiode; calculating and determining a first product of a scaling coefficient of each monochromatic light emitting diode and the optical power of a first calibration photodiode in the detection efficiency measurement process of the single photon detector to be measured; and then calculating and determining the reciprocal value of a second product between the Planckian constant and the light velocity in vacuum, and based on a third product among the first ratio, the second ratio, the first product and the reciprocal value of the second product, taking the third product as the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured.

More specifically, the scaling factor obtained in connection with the scaling measurementAnd the power measured by the first calibration photodiode 131 during the detection efficiency measurementAverage photon number irradiated onto photosensitive surface of single photon detectorThe calculation formula of (2) is expressed as follows:

,

Where h is the Planck constant, c is the speed of light in vacuum, The frequency of the light pulses emitted for each monochromatic light emitting diode (the same frequency as the monochromatic light emitting diode driving pulses),For the photosensitive area of the single photon detector to be measured,For the photosensitive area of the second calibration photodiode,Representing the optical power measured by the first calibrated photodiode during the measurement of the detection efficiency of the single photon detector to be measured,Scaling factors for each monochromatic light emitting diode.

Step S30, obtaining time interval data generated by the single photon detector to be measured in the event refreshing time-to-digital converter under the action of each light pulse with the same wavelength, and calculating and determining probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram so as to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse;

After determining the average incident photon number of each single-color light emitting diode irradiated to the photosensitive area of the single-photon detector to be measured, a computer terminal device 151 in a single-photon detector detection efficiency measurement system acquires time interval data generated by the single-photon detector to be measured under the action of each light pulse with the same wavelength in an event refreshing time-to-digital converter, calculates and determines probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram, so as to determine time domain photon probability distribution of the single-photon detector to be measured under the irradiation of each light pulse;

Further, referring to fig. 6, the step of obtaining time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in the event refresh time-to-digital converter, and calculating to determine probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram so as to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse includes:

Step S301, recording time interval data generated by the single photon detector to be measured under the action of each light pulse by adopting an event refreshing time-to-digital converter;

step S302, determining the width of each statistical subinterval of the statistical histogram, wherein each statistical subinterval represents a time interval range, and the width of each statistical subinterval is larger than the width of each single-color light-emitting diode emission pulse;

Step S303, distributing time interval data generated by the single photon detector to be measured under the action of each light pulse to each statistical subinterval to construct a statistical histogram;

Step S304, determining a count of a total event in the statistical histogram and a time interval range of each statistical subinterval, and determining a time-domain photon probability distribution of the single photon detector to be measured under irradiation of each light pulse based on a ratio between the count of the time interval range of each statistical subinterval and the total event in the statistical histogram to obtain a probability density of the time interval range of each statistical subinterval.

Specifically, after determining the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured, the computer terminal device 151 in the single-photon detector detection efficiency measurement system acquires time interval data generated by the single-photon detector to be measured under the action of each light pulse with the same wavelength in the event refreshing time-to-time converter, and the event refreshing time-to-time converter may be used to record the time interval data generated by the single-photon detector to be measured under the action of each light pulse; determining the width of each statistical subinterval of the statistical histogram, wherein each statistical subinterval represents a range of time intervals, the width of the statistical subinterval being greater than the width of each single color light emitting diode emission pulse, which ensures that all possible time interval data can be captured without omission; the single photon detector time interval data to be measured recorded in step S301 are distributed into predetermined statistical subintervals to construct a statistical histogram. The purpose of this step is to group and count the data for subsequent analysis and processing; the total number of events in the statistical histogram, i.e. the sum of all time interval data, is determined. Then, the time interval range of each statistical subinterval is counted, and the probability density of the time interval range of each statistical subinterval can be obtained based on the ratio between the count of the time interval range of each statistical subinterval and the total event number. This step enables to determine the time-domain photon probability distribution of the single photon detector to be measured under each light pulse irradiation, i.e. the probability describing the photon emission in each time interval range.

Step S40, fitting the time domain photon probability distribution by adopting a preset photoelectron counting model to determine the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse;

determining the time-domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse And then, fitting the time domain photon probability distribution measured by the event refreshing time-to-number converter module 141 by adopting a preset photoelectron counting model to determine the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse.

In some embodiments, the photoelectron counting model is:

，

wherein j represents a j-th statistical subinterval (Bin) of the statistical histogram; y represents the probability that the single photon detector cannot detect dark pulses within the time interval range of each statistical subinterval; z represents the probability that a single photon detector cannot detect both the photon-induced pulse and the dark pulse within the time interval range of each statistical subinterval; Representing a number of statistical subintervals contained within a delay time between a start pulse of the digitizer and the light pulse at the event refresh time; m represents the mth photon probability peak in the statistical histogram; n represents a period of The number of statistical subintervals contained between photon probability peaks; Representing a time-domain photon probability distribution.

More specifically, j represents the jth statistical subinterval (Bin) of the statistical histogram, which takes on a positive integer, and the time interval range (width) of each statistical subinterval (Bin) is Δt, the time t can be expressed as; Y represents the probability that a single photon detector will not detect a dark pulse within the time interval of each statistical subinterval, wherein,Which represents the probability that a single photon detector will not detect a dark pulse for a time deltat,Is the dark pulse count rate, the magnitude of which is given by the fit; z represents the probability that a single photon detector will not detect both photon-induced pulses and dark pulses within the time interval of each statistical subinterval, where,The probability that the single photon detector cannot detect the pulse and the dark pulse caused by photons at the same time in delta t is represented, and mu is the average photoelectron number detected by the single photon detector under the action of the single light pulse; Representing the number of statistical sub-intervals contained in the delay time between the start pulse of the digitizer and the light pulse at event refresh, wherein, Which represents the number of statistical subintervals (Bin) contained in the delay time between the start pulse and the light pulse of the digitizer at event refresh,Representing a delay time between a start pulse of the digitizer and the light pulse at the event refresh time; m represents the mth photon probability peak in the statistical histogram, n represents the period asA number of statistical subintervals (bins) contained between photon probability peaks; the exp () function is an exponential function for calculating a base of a base e of a natural logarithm.

In some embodiments, referring to fig. 7, the silicon single photon avalanche diode single photon detector is based on a time domain probability distribution (solid line) measured by an event refresh time-to-digital converter under 670 nm LED pulse light irradiation, and a dashed line is a probability distribution fitted by the above photoelectron counting model; dt is the width of the statistical subinterval (Bin), set to 500 ns, and the period isThe probability peak of (c) represents the probability of detecting a light pulse,The delay time between the start pulse of the digitizer and the light pulse at the event refresh time is indicated.

And step S50, determining the detection efficiency of the single photon detector to be measured based on the average incident photon number and the average photoelectron number so as to finish the measurement of the detection efficiency of the single photon detector.

After the average incident photon number of each monochromatic light emitting diode irradiated to the photosensitive area of the single photon detector to be measured and the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse are determined, the detection efficiency of the single photon detector to be measured is determined based on the average incident photon number and the average photoelectron number, so that the measurement of the detection efficiency of the single photon detector is completed.

Further, referring to fig. 8, the step of determining the detection efficiency of the single photon detector to be measured based on the average incident photon number and the average photoelectron number includes:

step S501, determining the average incident photon number of each monochromatic light emitting diode irradiated on a photosensitive area of a single photon detector to be measured and the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse;

Step S502, determining the detection efficiency of the single photon detector to be measured based on the ratio between the average photoelectron number detected by the single photon detector to be measured under the action of the single light pulse and the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single photon detector to be measured.

Specifically, the computer terminal device 151 in the single photon detector detection efficiency measurement system obtains the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single photon detector to be measured and the average photoelectron number of the single photon detector to be measured detected under the action of a single light pulse, and uses the ratio as the detection efficiency of the single photon detector to be measured based on the ratio between the average photoelectron number of the single photon detector to be measured detected under the action of the single light pulse and the average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single photon detector to be measured, so as to determine the detection efficiency of the single photon detector to be measured.

More specifically, the calculation formula of the detection efficiency of the single photon detector to be measured is expressed as follows:

,

wherein, Represents the detection efficiency of the single photon detector to be measured, mu represents the average photoelectron number detected by the single photon detector under the action of a single light pulse,Representing the average number of incident photons that each monochromatic light emitting diode impinges on the photosensitive area of the single photon detector to be measured.

As can be seen from the above embodiments, compared with the prior art, in order to obtain the actual photon counting rate, the application needs to perform dark counting, post-pulse and dead time correction on the actual counting rate, and these additional measurements and corrections not only greatly increase the complexity of the measurement of the detecting efficiency, but also introduce additional measurement errors, etc. in the single photon detector detecting efficiency measuring method in the prior art, the application includes but is not limited to the following advantages:

Referring to fig. 9, a single photon detector detection efficiency measurement apparatus according to one of the present application includes a scaling factor determination module 1100, an incident photon number determination module 1200, a probability distribution determination module 1300, an photoelectron number determination module 1400, and a detection efficiency determination module 1500. The calibration coefficient determining module 1100 is configured to respond to the detection efficiency measuring instruction of the single photon detector, and obtain the optical power of the first calibration photodiode and the second calibration photodiode under the irradiation of each single-color light emitting diode in the single-color light emitting diode array in the calibration measuring process so as to determine the calibration coefficient of each single-color light emitting diode; the incident photon number determining module 1200 is configured to calculate and determine an average incident photon number of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured according to the scaling factor, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode, and the optical power of the first calibration photodiode in the detection efficiency measurement process of the single-photon detector to be measured; the probability distribution determining module 1300 is configured to obtain time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in the event refreshing time-to-digital converter, calculate and determine probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram, so as to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse; the photoelectron number determining module 1400 is configured to fit the time-domain photon probability distribution by using a preset photoelectron counting model so as to determine the average photoelectron number detected by the single photon detector to be measured under the action of a single light pulse; the detection efficiency determining module 1500 is configured to determine the detection efficiency of the single photon detector to be measured based on the average number of incident photons and the average number of photons, so as to complete measurement of the detection efficiency of the single photon detector.

On the basis of any embodiment of the present application, referring to fig. 10, another embodiment of the present application further provides an electronic device, where the electronic device may be implemented by a computer device, and as shown in fig. 10, an internal structure of the computer device is schematically shown. The computer device includes a processor, a computer readable storage medium, a memory, and a network interface connected by a system bus. The computer readable storage medium of the computer device stores an operating system, a database and computer readable instructions, the database can store a control information sequence, and the computer readable instructions can enable the processor to realize a single photon detector detection efficiency measurement method when the computer readable instructions are executed by the processor. The processor of the computer device is used to provide computing and control capabilities, supporting the operation of the entire computer device. The memory of the computer device may have stored therein computer readable instructions that, when executed by the processor, cause the processor to perform the single photon detector detection efficiency measurement method of the present application. The network interface of the computer device is for communicating with a terminal connection. It will be appreciated by those skilled in the art that the structure shown in FIG. 10 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.

The processor in this embodiment is configured to execute specific functions of each module and its sub-modules in fig. 9, and the memory stores program codes and various types of data required for executing the above modules or sub-modules. The network interface is used for data transmission between the user terminal or the server. The memory in this embodiment stores the program codes and data required for executing all the modules/sub-modules in the single photon detector detection efficiency measurement apparatus of the present application, and the server can call the program codes and data of the server to execute the functions of all the sub-modules.

The present application also provides a storage medium storing computer readable instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of a method for measuring efficiency of a single photon detector according to any of the embodiments of the present application.

The application also provides a computer program product comprising computer programs/instructions which when executed by one or more processors implement the steps of the method for measuring the detection efficiency of a single photon detector according to any of the embodiments of the application.

Those skilled in the art will appreciate that all or part of the processes implementing the methods of the above embodiments of the present application may be implemented by a computer program for instructing relevant hardware, where the computer program may be stored on a computer readable storage medium, where the program, when executed, may include processes implementing the embodiments of the methods described above. The storage medium may be a computer readable storage medium such as a magnetic disk, an optical disk, a Read-Only Memory (ROM), or a random access Memory (Random Access Memory, RAM).

The foregoing is only a partial embodiment of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and adaptations can be made without departing from the principles of the present application, and such modifications and adaptations are intended to be comprehended within the scope of the present application.

In summary, the method for measuring the detection efficiency of the single photon detector provided by the application can rapidly and accurately measure the detection efficiency spectrum of the single photon detector in a wide spectrum range, does not need to additionally measure and correct the dead time, the dark count rate and the post-pulse probability of the single photon detector, greatly reduces the data quantity required to be directly measured, avoids introducing additional measurement errors, greatly improves the measurement efficiency, and simultaneously remarkably improves the measurement precision of the detection efficiency spectrum.

Claims

1. A method for measuring detection efficiency of a single photon detector, comprising:

2. The method of measuring the detection efficiency of a single photon detector as in claim 1 wherein the step of obtaining the optical power of the first calibration photodiode and the second calibration photodiode illuminated by each of the array of monochromatic light emitting diodes during the calibration measurement to determine the calibration coefficient of each of the monochromatic light emitting diodes comprises:

3. The method according to claim 1, wherein the step of calculating and determining the average number of incident photons of each single-color light emitting diode irradiated onto the photosensitive area of the single-photon detector to be measured based on the scaling factor, the photosensitive area of the single-photon detector to be measured, the photosensitive area of the second calibration photodiode, and the optical power of the first calibration photodiode during the measurement of the detection efficiency of the single-photon detector to be measured comprises:

4. The method for measuring the detection efficiency of the single photon detector according to claim 1, wherein the step of obtaining time interval data generated by the single photon detector to be measured under the action of each light pulse with the same wavelength in the event refresh time-to-digital converter, calculating and determining probability density of the time interval data falling into a statistical subinterval of a preset statistical histogram to determine time domain photon probability distribution of the single photon detector to be measured under the irradiation of each light pulse comprises the following steps:

5. The method for measuring the detection efficiency of the single photon detector according to claim 1, wherein the photoelectron counting model is as follows:

，

6. The method according to claim 1, characterized in that the step of determining the detection efficiency of the single photon detector to be measured based on the average number of incident photons and the average number of photoelectrons includes:

7. The method according to any one of claims 1 to 6, wherein the photosensitive region of the second calibration photodiode is located at the same position as the photosensitive region of the single photon detector to be measured, the wavelength of each single color light emitting diode in the single color light emitting diode array is different, and the single photon detector to be measured includes a photomultiplier tube or a single photon avalanche diode.

8. A single photon detector detection efficiency measurement device, comprising:

9. An electronic device comprising a central processor and a memory, characterized in that the central processor is arranged to invoke a computer program stored in the memory for performing the steps of the method according to any of claims 1 to 7.

10. A computer-readable storage medium, characterized in that it stores in the form of computer-readable instructions a computer program implemented according to the method of any one of claims 1 to 7, which, when invoked by a computer, performs the steps comprised by the corresponding method.