Method for calibrating performance parameters of free-running mode single photon detector

Abstract

The application provides a performance parameter calibration method of a free-running mode single photon detector, and relates to the technical field of photoelectric detection. The application continuously collects photon counting data of a free-running mode single photon detector on a pulsed single photon source, adopts a coincidence counting method to mark a signal photon-containing pulse period and a signal photon-not-containing pulse period, and respectively uses the signal photon-containing pulse period and the signal photon-not-containing pulse period as a signal parameter calibration sample and a noise parameter calibration sample. Based on the above group of continuous photon counting data, parameter estimation of a dark counting rate, a photon detection efficiency, a cumulative pulse probability and a time jitter can be simultaneously realized, the number of data collection times is reduced, and measurement consistency is well maintained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoelectric detection, and in particular to a performance parameter calibration method of a free-running mode single-photon detector. BACKGROUND

[0002] Single-photon detectors have extremely high response sensitivity and can respond to extremely weak signals at the level of photon energy, and have wide applications in quantum secure communication, long-distance laser ranging and three-dimensional imaging, biomedical imaging and other fields. At present, single-photon detectors include various types, such as photomultiplier tubes (PMTs), avalanche photodiodes (APDs), superconducting nanowire single-photon detectors (SNSPDs), etc. Although there are many types of single-photon detectors, their basic function is to respond to single or multiple photons and output corresponding electrical pulse signals. The performance of a single-photon detector can generally be calibrated by several common indicators, such as photon detection efficiency, dark count rate, post-cumulative pulse probability, and detection time jitter.

[0003] The working performance of a single-photon detector is mainly determined by working temperature, bias voltage, dead time and other parameters. Since different application backgrounds have different requirements for the performance of single-photon detectors, the working parameters and corresponding detection performance of single-photon detectors need to be calibrated. For the performance calibration of single-photon detectors for specific wavelengths, the dark count rate is first measured under no light conditions, and then the photon detection efficiency, post-cumulative pulse probability, and detection time jitter under different working conditions are calibrated using a single-photon source.

[0004] Therefore, the existing calibration process needs to collect multiple sets of data to complete the calibration of a set of parameters of a single-photon detector. SUMMARY

[0005] (I) Technical problems solved

[0006] In view of the deficiencies in the prior art, the present application provides a performance parameter calibration method of a free-running mode single-photon detector, which solves the technical problem that multiple sets of data need to be collected to complete the calibration of a set of parameters of a single-photon detector.

[0007] (II) Technical solutions

[0008] To achieve the above object, the present application is implemented by the following technical solutions:

[0009] A performance parameter calibration method of a free-running mode single-photon detector, characterized in that it comprises:

[0010] Continuous acquisition of photon counting data of a free-running mode single-photon detector on a pulsed single-photon source, and use of a coincidence counting method to mark out pulse periods containing signal photons and pulse periods not containing signal photons, which are used as signal parameter calibration samples and noise parameter calibration samples, respectively;

[0011] Calibrating the dark count rate by using the noise parameter calibration sample and the trigger period of the pulsed single photon source;

[0012] Calibrating the photon detection efficiency by counting the number of coincidence photons in the signal parameter calibration sample, correcting the coincidence count gate width and the dark count rate, and combining the average number of photons per pulse of the pulsed single photon source;

[0013] Calibrating the post-accumulation pulse probability by counting the number of photons other than coincidence photons in the signal parameter calibration sample, subtracting the corresponding dark count to obtain the post-accumulation pulse count, and correcting the dark count rate, the photon detection efficiency, and the post-accumulation pulse probability;

[0014] Calibrating the detection time jitter by fitting the time distribution of coincidence photons in the signal parameter calibration sample with a Gaussian function;

[0015] Calibrating the performance parameters of the free-running mode single photon detector according to the dark count rate, the photon detection efficiency, the post-accumulation pulse probability, and the detection time jitter.

[0016] Preferably, the performance parameter calibration method of the free-running mode single photon detector further comprises:

[0017] Calculating the standard deviations of the dark count rate, the photon detection efficiency, and the post-accumulation pulse probability using Poisson statistics, and using each standard deviation to quantitatively evaluate the accuracy of the corresponding performance parameter of the free-running mode single photon detector.

[0018] Preferably, the dark count rate r d is calculated as follows:

[0019]

[0020] where i is the pulse period index in the photon count data, N is the number of pulse periods, n i is the number of photon counts in pulse period i, T is the pulse period, and g(i) is a step function, g(i)=1 when pulse period i contains a coincidence photon, and g(i)=0 when pulse period i does not contain a coincidence photon.

[0021] Preferably, the photon detection efficiency η p is calculated as follows:

[0022]

[0023] where τ is the coincidence count gate width, and μ is the average number of photons per pulse of the pulsed single photon source.

[0024] Preferably, the post-accumulation pulse probability P ap is calculated as follows:

[0025]

[0026] wherein T dead is the single photon detector dead time.

[0027] Preferably, a Gaussian function is used to fit the time distribution of the coincidence photon counts within the signal pulse period, to obtain the single photon detector photon counting time jitter jitter ; wherein μ delay is the Gaussian distribution mean, and τ pulse is the full width at half maximum of the laser pulse calibrated for the system.

[0028] Preferably, the standard deviation of the dark count rate is calculated using Poisson statistics, for quantitatively evaluating the precision of the corresponding performance parameters of the free-running mode single photon detector;

[0029] The calculation method of the dark count rate standard deviation d is as follows:

[0030]

[0031] Preferably, the standard deviation of the photon detection efficiency is calculated using Poisson statistics, for quantitatively evaluating the precision of the corresponding performance parameters of the free-running mode single photon detector;

[0032] The calculation method of the photon detection efficiency standard deviation p is as follows:

[0033]

[0034] Preferably, the standard deviation of the post-accumulation pulse probability is calculated using Poisson statistics, for quantitatively evaluating the precision of the corresponding performance parameters of the free-running mode single photon detector;

[0035] The calculation method of the post-accumulation pulse probability standard deviation ap is as follows:

[0036]

[0037] (Three) beneficial effects

[0038] The present application provides a performance parameter calibration method for a free-running mode single photon detector. Compared with the prior art, the following beneficial effects are achieved:

[0039] The application continuously collects photon counting data of a free running mode single photon detector on a pulsed single photon source, adopts coincidence counting method to mark out a signal photon containing pulse period and a signal photon not containing pulse period, and uses them as signal parameter calibration sample and noise parameter calibration sample respectively; based on the above continuous photon counting data, the parameter estimation of dark counting rate, photon detection efficiency, cumulative pulse probability and time jitter can be simultaneously realized, the data collection times are reduced, and the measurement consistency is well maintained. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0041] Figure 1 A calibration system schematic diagram of a free running mode single photon detector parameter calibration method provided by the embodiment of the present application;

[0042] Figure 2 A sample marking schematic diagram of a free running mode single photon detector parameter calibration method provided by the embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0044] The embodiment of the present application provides a performance parameter calibration method of a free running mode single photon detector, which solves the technical problem that a plurality of groups of data need to be collected to complete the calibration of a single photon detector.

[0045] The technical solution in the embodiment of the present application is as follows to solve the above technical problem:

[0046] This invention continuously acquires photon count data from a pulsed single-photon source using a free-running single-photon detector. It employs a coincidence counting method to mark the pulse periods containing signal photons and those without, using these as calibration samples for signal parameters and noise parameters, respectively. Based on this continuous set of photon count data, it can simultaneously estimate parameters such as dark count rate, photon detection efficiency, cumulative pulse probability, and time jitter, reducing the number of data acquisitions and maintaining good measurement consistency.

[0047] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0048] This invention provides a method for calibrating the performance parameters of a free-running mode single-photon detector, including:

[0049] Photon counting data of pulsed single-photon sources were continuously acquired from a single-photon detector in free-running mode. The pulse period containing signal photons and the pulse period without signal photons were marked using the coincidence counting method, and used as signal parameter calibration samples and noise parameter calibration samples, respectively.

[0050] The dark count rate was determined by calibrating the sample and the triggering period of the pulsed single-photon source using the noise parameters.

[0051] The number of coincident photons in the signal parameter calibration sample is counted, and the dark count rate and coincidence count gate width are used for correction. The photon detection efficiency is determined by combining the average number of photons per pulse of the pulsed single-photon source.

[0052] The number of photons other than coincident photons in the signal parameter calibration sample is counted, and the corresponding dark count is subtracted to obtain the cumulative pulse count, thereby calibrating the cumulative pulse probability.

[0053] The temporal distribution of coincident photons in the sample is calibrated based on the signal parameters, and the detection time jitter is obtained by fitting a Gaussian function.

[0054] The performance parameters of the free-running mode single-photon detector are calibrated based on the dark count rate, photon detection efficiency, cumulative pulse probability, and detection time jitter.

[0055] Based on the aforementioned set of continuous photon counting data, the embodiments of the present invention can simultaneously estimate parameters such as dark count rate, photon detection efficiency, cumulative pulse probability, and time jitter, thereby reducing the number of data acquisitions and maintaining good measurement consistency.

[0056] Furthermore, in existing technologies, single-photon detection is a probabilistic process, and parameter estimation is often accompanied by significant statistical uncertainty, with no quantitative assessment of the number of samples collected.

[0057] To overcome the above-mentioned technical defects, in an optional embodiment, Poisson statistics are used to calculate the standard deviations of the dark count rate, photon detection efficiency, and cumulative pulse probability, respectively. Each standard deviation is used to quantitatively evaluate the accuracy of the performance parameters corresponding to the free-running mode single-photon detector.

[0058] By providing the standard deviations of the dark count rate, photon detection efficiency, and accumulated pulse probability parameters, the measurement accuracy is reflected, which can be used to avoid statistical uncertainties caused by photon count fluctuations.

[0059] Example:

[0060] A method for calibrating parameters of a free-running mode single-photon detector, employing methods such as... Figure 1 The pulsed single-photon source and data acquisition system shown:

[0061] The pulsed single-photon source uses a PicoQuant PDL 800-D picosecond pulsed laser driver and a PicoQuant PC-1550 laser to generate picosecond laser pulses with a wavelength of 1550nm, a pulse repetition frequency of 100kHz, a pulse width of 80ps, and a power of -60dBm. These pulses are attenuated to -118.9dBm by an AV6381B digitally adjustable optical attenuator and coupled to a single-photon detector via fiber optic cable. The single-photon detector is a Geiger-mode InGaAs / InP free-running single-photon detector with a set dead time of 500ns. A PicoQuant PicoHarp 150 time-correlated photon counter (TCSPC) is used to record photon count data. The synchronization signal of the PDL800-D driver is connected to TCSPC channel 0, and the output of the single-photon detector is connected to TCSPC channel 1.

[0062] Based on the time data measured by the two channels of TCSPC, the photon flight time was calculated, and a photon flight time histogram was plotted, as shown below. Figure 2 As shown, the time interval where the pulse is located in the histogram is taken as the photon counting coincidence interval, and other intervals within the pulse period are taken as non-coincidence intervals.

[0063] Among them, the photon counts within the coincidence interval are used as signal parameter calibration samples, and the photon counts outside the coincidence interval are used as noise parameter calibration samples. For pulse period i in a continuous sample, a step function g(i) is used to indicate whether it contains coincidence photons. When pulse period i contains coincidence photons, g(i) = 1; when pulse period i does not contain coincidence photons, g(i) = 0.

[0064] The dark count rate was calibrated using noise parameters to determine the sample and the trigger period of the pulsed single-photon source, T = 10 μs. The dark count rate r was then calibrated. d The calculation method is as follows:

[0065]

[0066] Where i is the pulse period index in the photon counting data, N is the number of pulse periods, and n i Let be the number of photons counted within pulse period i, and T be the pulse period.

[0067] Standard deviation of dark count rate σ d The calculation method is as follows:

[0068]

[0069] The number of coincidence photons in the sample is calibrated using statistical signal parameters, and the photon detection efficiency is calibrated by correcting for dark count rate and coincidence count gate width. The photon detection efficiency η p The calculation method is as follows:

[0070]

[0071] Where τ is the coincidence counting gate width, and μ is the average number of photons per pulse of the pulsed single-photon source;

[0072] Standard deviation of photon detection efficiency σ p The calculation method is as follows:

[0073]

[0074] The statistical signal parameters determine the number of photons other than coincident photons in the sample. The accumulated pulse count is obtained by subtracting the corresponding dark count, and the accumulated pulse probability P is calculated. ap The calculation method is as follows:

[0075]

[0076] Among them, T dead For single-photon detector dead time; cumulative pulse probability standard deviation σ ap The calculation method is as follows:

[0077]

[0078] The temporal distribution of coincidence photons in the sample is calibrated based on signal parameters using a Gaussian function. By fitting the time distribution of coincidence photon counts within the signal pulse period, the photon count time jitter σ of the single-photon detector can be obtained. jitter , where μ delay Let τ be the mean of a Gaussian distribution. pulse The full width at half maximum (FWHM) of the laser pulse is used to calibrate the system.

[0079] In summary, compared with existing technologies, it has the following beneficial effects:

[0080] 1. The embodiments of the present invention use a set of continuous photon counting data, which can simultaneously estimate the parameters of dark count rate, photon detection efficiency, cumulative pulse probability, and time jitter, reduce the number of data acquisitions, and maintain measurement consistency better.

[0081] 2. The embodiments of the present invention provide the standard deviation of the dark count rate, photon detection efficiency, and cumulative pulse probability parameter estimation, as well as the full width at half maximum (FWHM) of the laser pulse of the calibration system corresponding to the detection time jitter, reflecting the measurement accuracy and being able to avoid statistical uncertainties caused by photon count fluctuations.

[0082] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calibrating the performance parameters of a free-running mode single-photon detector, characterized in that, include: Photon counting data of pulsed single-photon sources were continuously acquired from a single-photon detector in free-running mode. The pulse period containing signal photons and the pulse period without signal photons were marked using the coincidence counting method, and used as signal parameter calibration samples and noise parameter calibration samples, respectively. The dark count rate was determined by calibrating the sample and the triggering period of the pulsed single-photon source using the noise parameters. The number of coincident photons in the signal parameter calibration sample is counted, and the dark count rate and coincidence count gate width are used for correction. The photon detection efficiency is determined by combining the average number of photons per pulse of the pulsed single-photon source. The number of photons other than coincident photons in the signal parameter calibration sample is counted, and the corresponding dark count is subtracted to obtain the cumulative pulse count, thereby calibrating the cumulative pulse probability. The temporal distribution of coincident photons in the sample is calibrated based on the signal parameters, and the detection time jitter is obtained by fitting a Gaussian function. Based on the dark count rate, photon detection efficiency, accumulated pulse probability, and detection time jitter, the performance parameters of the free-running mode single-photon detector are calibrated. The dark count rate The calculation method is as follows: in, This is the pulse period index in the photon counting data. This represents the number of pulse cycles. Pulse period The number of photons inside, The pulse period; For step functions, when the pulse period When it contains coincidence photons When the pulse period When it does not contain coincident photons ; Photon detection efficiency The calculation method is as follows: in, To meet the counting gate width, The average number of photons per pulse from a pulsed single-photon source; The accumulated pulse probability The calculation method is as follows: in, This refers to the dead time of a single-photon detector. Using Gaussian function By fitting the time distribution of coincidence photon counts within the signal pulse period, the photon count time jitter of the single-photon detector is obtained. ;in, The mean is a Gaussian distribution. The full width at half maximum (FWHM) of the laser pulse is used to calibrate the system.

2. The method for calibrating the performance parameters of a free-running mode single-photon detector as described in claim 1, characterized in that, Also includes: Poisson statistics were used to calculate the standard deviations of the dark count rate, photon detection efficiency, and cumulative pulse probability, respectively. Each standard deviation was used to quantitatively evaluate the accuracy of the corresponding performance parameters of the single-photon detector in this free-running mode.

3. The method for calibrating the performance parameters of a free-running mode single-photon detector as described in claim 1, characterized in that, Poisson statistics were used to calculate the standard deviation of the dark count rate, which was used to quantitatively evaluate the accuracy of the performance parameters of the single-photon detector in this free-running mode. The standard deviation of the dark count rate The calculation method is as follows:

4. The method for calibrating the performance parameters of a free-running mode single-photon detector as described in claim 1, characterized in that, Poisson statistics were used to calculate the standard deviation of the photon detection efficiency, which was used to quantitatively evaluate the accuracy of the performance parameters of the single-photon detector in this free-running mode. The standard deviation of the photon detection efficiency The calculation method is as follows:

5. The method for calibrating the performance parameters of a free-running mode single-photon detector as described in claim 1, characterized in that, Poisson statistics were used to calculate the standard deviation of the accumulated pulse probability, which was used to quantitatively evaluate the accuracy of the performance parameters of the single-photon detector in this free-running mode. The standard deviation of the accumulated pulse probability The calculation method is as follows:

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