Single photon detection device and single photon detection method

Abstract

The present invention discloses a single-photon detection device including an interference unit, wherein the interference unit includes: a signal distribution module, configured to divide an input signal into a first signal and a second signal; a first signal path, coupled to the signal distribution module, configured to receive the first signal and transmit; a second signal path, coupled to the signal distribution module, configured to receive the second signal, filter out a signal of a preset frequency component and transmit; a phase shift module, arranged in the first signal path or the second signal path, configured to shift the phase of the transmission signal by 180°; a coupling module, coupled to the first signal path and the second signal path, configured to receive the output signals of the first signal path and the second signal path, and output them after coupling. The single-photon detection device provided by the present invention eliminates a large number of gated interference signals, and has a significant optimization effect on the detection efficiency, post-pulse effect, and time resolution of the single-photon detection device.

Description

Technical Field

[0001] The present invention relates to the technical field of weak light detection, and in particular to a single photon detection device comprising an interference unit and a method for performing single photon detection using the single photon detection device. Background Art

[0002] Due to the need for weak light sensing and detection in fields such as quantum key distribution, fiber optic sensing, fiber optic communication, lidar, high energy physics, semiconductor device characteristic analysis, and biological imaging, single photon detection devices based on semiconductor avalanche photodiodes (APDs) have been widely used. Among them, APDs used in the fiber optic communication band (1310 nanometers and 1550 nanometers) are mainly based on indium gallium arsenide (InGaAs) materials.

[0003] In order to suppress the post-pulse noise of the single-photon detection device based on InGaAs APD and improve the photon counting rate of the single-photon detection device, the avalanche photodiode is usually gate-driven to reduce the avalanche charge and the recovery time after the avalanche. Silicon-based APD also uses a gate drive method. However, due to the parasitic capacitance of the avalanche photodiode and the circuit, the capacitive response of the gate signal will mask the avalanche signal caused by the photon. Therefore, the capacitive response of the gate signal must be effectively eliminated.

[0004] In the prior art, there are technical solutions of active cancellation, band-stop filtering, low-pass filtering and self-differentiation. Among them, the active cancellation technology can effectively eliminate the fundamental frequency and high-order harmonic frequency of the gate signal capacitance response at the APD output end, and has a relatively wide and continuous frequency domain passband to process avalanche narrow pulse signals. However, when the temperature and bias voltage of the APD change, the gate signal capacitance response at the APD output end will also change. At this time, the active cancellation technology needs to be readjusted to eliminate the gate signal capacitance response signal at the APD output end, and its applicability is limited.

[0005] The band-stop filtering technology uses multiple RF band-stop filters to suppress the fundamental frequency and higher harmonic frequencies of the gate signal capacitor response at the output end of the APD. The general stopband bandwidth of the band-stop filter is in the order of 100-300MHz, and has a certain transition band. Although this solution has a wider frequency domain passband to process avalanche narrow pulse signals, there will be large frequency domain discontinuities near the fundamental frequency and higher harmonic frequency points of the gate signal, which will reduce the signal-to-noise ratio of the avalanche narrow pulse signal, and the pulse waveform will have a certain degree of widening and distortion, and the jitter will increase.

[0006] The frequency domain passband of the low-pass filtering scheme used to process avalanche narrow pulse signals is relatively small, generally not exceeding 90% of the gate signal frequency. A smaller frequency domain processing bandwidth will reduce the signal-to-noise ratio of the avalanche narrow pulse signal, widen and distort the pulse waveform, and increase the jitter.

[0007] Self-differential technology requires that both differential signal channels transmit and process wide-band signals, and places high demands on the broadband performance of the device. Summary of the invention

[0008] In view of at least one defect of the prior art, the present invention provides a single photon detection device, including an interference unit, wherein the interference unit includes:

[0009] a signal distribution module configured to divide an input signal into a first signal and a second signal;

[0010] A first signal path, coupled to the signal distribution module, configured to receive the first signal and transmit;

[0011] A second signal path is coupled to the signal distribution module and configured to receive the second signal, filter out a signal of a preset frequency component from the second signal, and transmit the signal;

[0012] a phase shift module, disposed in the first signal path or the second signal path, configured to shift the phase of the transmission signal by 180°;

[0013] The coupling module is coupled to the first signal path and the second signal path, and is configured to receive output signals of the first signal path and the second signal path and output them after coupling.

[0014] According to one aspect of the present invention, a difference between the transmission distances of the first signal path and the second signal path is smaller than a first preset value.

[0015] According to one aspect of the present invention, the second signal path comprises:

[0016] A narrowband filtering module, wherein the passband of the narrowband filtering module includes the preset frequency component.

[0017] According to one aspect of the present invention, the passband bandwidth of the narrowband filtering module is less than or equal to 10 MHz.

[0018] According to one aspect of the present invention, the narrowband filtering module includes one or more of a surface acoustic wave filter, a bulk acoustic wave filter, and a dielectric filter.

[0019] According to one aspect of the present invention, the first signal path comprises:

[0020] The power attenuation module is configured to adjust the power of the first signal so that the difference between the power of the output signals of the first signal path and the second signal path is smaller than a second preset value.

[0021] According to one aspect of the present invention, the power attenuation module includes one or more of an analog voltage-controlled attenuator, a digitally controlled step attenuator, and a resistor network attenuator.

[0022] According to one aspect of the present invention, the phase shift module is arranged on the second signal path.

[0023] According to one aspect of the present invention, the phase shift module includes one or more of a radio frequency transmission line, an analog voltage-controlled phase shifter, a digitally controlled step phase shifter, a capacitor network phase shifter, an inductor network phase shifter, and a capacitor-inductor hybrid network phase shifter.

[0024] According to one aspect of the present invention, the signal distribution module and the coupling module respectively include a three-port RF matching device, the three-port RF matching device includes a first end, a second end and a third end, and the three-port RF matching device of the signal distribution module is configured as follows:

[0025] The first end is coupled to the single photon sensing device and configured to receive the input signal;

[0026] The second end is coupled to the first signal path and configured to output the first signal;

[0027] The third terminal is coupled to the second signal path and configured to output the second signal;

[0028] The three-port RF matching device of the coupling module is configured as follows:

[0029] The second end is coupled to the second signal path and configured to receive an output signal of the second signal path;

[0030] The third terminal is coupled to the first signal path and configured to receive an output signal of the first signal path;

[0031] The first end outputs a signal after coupling the output signal of the first signal path and the output signal of the second signal path.

[0032] According to one aspect of the present invention, the three-port radio frequency matching device comprises a directional coupler, and the second end and the third end of the directional coupler have a preset signal isolation.

[0033] According to one aspect of the present invention, the single photon detection device further comprises:

[0034] A single photon sensing device configured to receive an optical signal and convert it into an electrical signal for output;

[0035] a DC voltage source coupled to the single-photon sensing device and configured to provide a DC bias voltage to the single-photon sensing device so as to put the single-photon sensing device in a critical breakdown state;

[0036] A gating signal generator is coupled to the single-photon sensing device and is configured to provide a gating signal to the single-photon sensing device; wherein

[0037] The input signal includes the electrical signal and an interference signal generated by a capacitance response of the gate signal.

[0038] According to one aspect of the present invention, the gating signal comprises a periodic signal, and the preset frequency component comprises one frequency component of the gating signal.

[0039] According to one aspect of the present invention, the single photon detection device comprises a plurality of the interference units, wherein:

[0040] A plurality of the interference units are cascaded, and the second signal path of each interference unit filters out an interference signal corresponding to one of the frequency components of the gated signal.

[0041] According to one aspect of the present invention, the single photon detection device further comprises:

[0042] A plurality of signal amplifying units, each of which is disposed before one of the interference units along the transmission direction of the input signal, and is configured to amplify the input signal.

[0043] According to one aspect of the present invention, the single photon detection device further comprises:

[0044] The low-pass filtering unit is arranged behind the plurality of interference units along the transmission direction of the input signal, and is configured to perform low-pass filtering on the output signals filtered by the plurality of interference units.

[0045] The present invention also provides a chip, which includes the single-photon detection device as described above integrated thereon.

[0046] The present invention also provides a method for single photon detection using the single photon detection device as described above, comprising:

[0047] Providing a DC bias voltage to the single-photon sensing device through a DC voltage source, so that the single-photon sensing device is in a critical breakdown state;

[0048] Providing a gating signal to the single-photon sensing device through a gating signal generator;

[0049] Receiving the optical signal through the single-photon sensing device and converting it into an electrical signal;

[0050] The input signal is divided into a first signal and a second signal by the signal distribution module, wherein the input signal includes the electrical signal and an interference signal generated by the capacitance response of the gate signal;

[0051] receiving and transmitting the first signal through the first signal path;

[0052] receiving the second signal through the second signal path, filtering out a signal of a preset frequency component from the second signal and transmitting the signal;

[0053] The phase of the transmission signal is shifted by 180° by the phase shift module;

[0054] The output signals of the first signal path and the second signal path are received by the coupling module and output after coupling.

[0055] According to one aspect of the present invention, a difference between the transmission distances of the first signal path and the second signal path is smaller than a first preset value.

[0056] According to one aspect of the present invention, wherein the second signal path includes a narrowband filtering module, the passband of the narrowband filtering module includes the preset frequency component, and the passband bandwidth of the narrowband filtering module is less than or equal to 10 MHz, the method further includes:

[0057] The second signal is filtered by the narrowband filtering module.

[0058] According to one aspect of the present invention, the first signal path includes a power attenuation module; the method further includes:

[0059] The power of the first signal is adjusted by the power attenuation module so that the difference between the power of the output signals of the first signal path and the second signal path is smaller than a second preset value.

[0060] According to one aspect of the present invention, the signal distribution module and the coupling module respectively include a three-port radio frequency matching device, the three-port radio frequency matching device includes a first end, a second end and a third end, wherein the three-port matching device of the signal distribution module is configured as follows: the first end is coupled to the single photon sensing device, the second end is coupled to the first signal path, and the third end is coupled to the second signal path; the three-port matching device of the coupling module is configured as follows: the second end is coupled to the second signal path, and the third end is coupled to the first signal path, and the method further includes:

[0061] Receiving the input signal through a first end of a three-port radio frequency matching device of the signal distribution module;

[0062] Outputting the first signal through the second end of the three-port radio frequency matching device of the signal distribution module;

[0063] Outputting the second signal through a third terminal of the three-port radio frequency matching device of the signal distribution module;

[0064] receiving the output signal of the second signal path through the second end of the three-port radio frequency matching device of the coupling module;

[0065] receiving the output signal of the first signal path through the third terminal of the three-port radio frequency matching device of the coupling module;

[0066] The output signal of the first signal path is coupled with the output signal of the second signal path through the first end of the three-port radio frequency matching device of the coupling module, and the signal is output.

[0067] According to one aspect of the present invention, the single photon detection device comprises a plurality of interference units, and the plurality of interference units are cascaded; the preset frequency component comprises one of the frequency components of the gating signal; and the method further comprises:

[0068] An interference signal corresponding to one of the frequency components of the gated signal is filtered out through the second signal path of each interference unit.

[0069] According to one aspect of the present invention, the single photon detection device further comprises a plurality of signal amplification units, each of which is arranged before one of the interference units along the transmission direction of the input signal, and the method further comprises:

[0070] The input signal is amplified by the multiple signal amplification units.

[0071] According to one aspect of the present invention, the single photon detection device further comprises a low-pass filtering unit, which is arranged after the plurality of interference units along the transmission direction of the input signal, and the method further comprises:

[0072] The output signal filtered by the plurality of interference units is subjected to low-pass filtering by the low-pass filtering unit.

[0073] The present invention also provides a non-transitory computer-readable storage medium having computer-readable instructions stored thereon. When the instructions are executed by a processor, the processor is enabled to execute the method described above.

[0074] The single-photon detection device, electrical chip and method for single-photon detection provided by the present invention include an interference unit, and the fundamental or higher harmonic signal frequency component of the gated interference signal is obtained by filtering through an extremely narrow bandpass filter, and then interferes with the main transmission signal (including the electrical signal after photoelectric conversion and the gated interference signal) through a coupling module. The interference phenomenon only occurs in the passband and transition band of the extremely narrow bandpass filter from the perspective of the entire frequency domain, so the impact on the main transmission signal is very small. Through multi-stage filtering, a large number of gated interference signals are effectively eliminated, and a relatively wide and continuous frequency domain passband can be stably provided to process avalanche narrow pulse signals, which has little impact on the signal-to-noise ratio, pulse waveform and jitter of the avalanche narrow pulse signal, and has a significant optimization effect on the detection efficiency, post-pulse effect and time resolution of the single-photon detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by the present application.

[0076] Figure 1 A detection device including an avalanche photodiode and its volt-ampere characteristic curve are shown;

[0077] Figure 2 shows the waveform of the gate voltage signal applied to the avalanche photodiode;

[0078] Figure 3 The output signal waveform of the single photon detection device in the prior art is shown;

[0079] Figure 4 An interferometer unit of a single photon detection device provided by an embodiment of the present invention is shown;

[0080] Figure 5 An interferometer unit of a single photon detection device provided by an embodiment of the present invention is shown;

[0081] Figure 6 shows a frequency response curve of an extremely narrow bandpass filter in a single photon detection device provided by an embodiment of the present invention;

[0082] Figure 7 An interferometer unit of a single photon detection device provided by an embodiment of the present invention is shown;

[0083] Figure 8 An interferometer unit of a single photon detection device provided by an embodiment of the present invention is shown;

[0084] Fig. 9 A single-photon detection device including an interference unit provided by one embodiment of the present invention is shown;

[0085] Fig. 10A shows a frequency response curve of an interference unit of a single photon detection device provided by an embodiment of the present invention;

[0086] Fig. 10B shows a frequency response curve of an interference unit of a single photon detection device provided by an embodiment of the present invention;

[0087] Fig.11 A single-photon detection device including an interference unit provided by one embodiment of the present invention is shown;

[0088] Fig.12 The output signal waveform of a single-photon detection device including an interference unit provided by one embodiment of the present invention is shown;

[0089] Fig.13 A single-photon detection device including an interference unit provided by one embodiment of the present invention is shown;

[0090] Fig.14 A single-photon detection device including an interference unit provided by one embodiment of the present invention is shown;

[0091] Fig.15 A method for single photon detection provided by an embodiment of the present invention is shown;

[0092] Fig.16A A device structure diagram of a single photon detection device provided by an embodiment of the present invention is shown;

[0093] Fig. 16B A histogram showing the temporal distribution of detection events of a single-photon detection device provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0094] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0095] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

[0096] Single photon detection devices usually use avalanche photodiodes (APDs) as photoelectric sensing devices. APDs work under reverse bias, and their working curves are as follows: Figure 1 As shown ( Figure 1 ) shows a detection device including an avalanche photodiode and its working curve. When there is no incident photon, the reverse current is extremely weak and is called dark current. When there is incident photon, the carriers (electron-hole pairs) generated by light absorption will be separated by the electric field to generate a reverse current, which is called photocurrent. In the linear working area, that is, when the APD reverse bias voltage is lower than the breakdown voltage, the photocurrent is proportional to the light intensity. At this time, the APD does not have the single-photon detection function. However, when the APD bias voltage is higher than its breakdown voltage, the carriers generated by a single photon are accelerated to sufficient energy by the electric field and can be ionized by collision to generate new electron-hole pairs, achieving a continuous carrier multiplication effect (i.e., avalanche effect), thereby generating a detectable macroscopic current signal. Under high bias, the sensitivity of the avalanche photodiode can sense optical signals at the single-photon level, and is suitable for single-photon detection devices required in fields such as quantum key distribution and quantum direct communication.

[0097] Avalanche photodiodes have an after-pulse effect, that is, after an avalanche occurs, the avalanche photodiode randomly generates a secondary avalanche in the absence of photon incidence for a period of time. After-pulses are a type of detector noise and must be suppressed as much as possible. After-pulses are related to avalanche current. The larger the avalanche current, that is, the higher the APD reverse bias, the more significant the after-pulse. In order to suppress after-pulses, the reverse bias of the APD cannot be set too high, which will affect the single-photon detection efficiency of the APD. At the same time, the APD detector usually introduces a longer dead time, that is, after a long period of time after successfully detecting a single-photon avalanche signal, no photon counting is performed, thereby reducing the detection count rate of the single-photon detection device. In order to improve the photon counting rate and detection efficiency of the single-photon detection device, a gate drive method is usually used for the avalanche photodiode, such as Figure 1 As shown, a DC bias is applied to the avalanche photodiode to put it in a critical breakdown state. On the basis of applying the DC bias, a periodically changing gate signal is applied to the avalanche photodiode. Figure 2As shown, optionally, the gating signal applied to the avalanche photodiode includes a periodic signal, such as one or more of a sinusoidal signal, a square wave signal, and a triangular wave signal ( Figure 2 The waveforms of two gating signals are shown in Figure 1). Within a certain time of the gating signal, the avalanche photodiode is in an avalanche breakdown state, and avalanche can occur by receiving a single-photon light signal, outputting an avalanche current; within the remaining time of the gating signal, since the reverse bias voltage is lower than the breakdown voltage, the avalanche current will be quenched, thereby reducing the avalanche charge and the recovery time after the avalanche. By applying a gating voltage signal, the post-pulse effect of the avalanche photodiode is effectively suppressed, and the photon counting rate and detection efficiency of the single-photon detection device are improved.

[0098] However, due to the parasitic capacitance of the avalanche photodiode and its connected circuits, the capacitive response caused by the gate signal injection will mask the avalanche signal caused by the photons. Figure 3 As shown, the output signal of the avalanche photodiode includes a large amount of interference signals generated by the capacitance response of the gate signal, making it difficult to read the electrical signal generated by the incident light signal. Therefore, the interference signal introduced by the capacitance response of the gate signal must be effectively eliminated.

[0099] The present invention provides a single-photon detection device including an interference unit, which adopts an extremely narrow-band interference circuit to eliminate the fundamental frequency component and the higher harmonic frequency component of the interference signal generated by the capacitance response of the gated signal at the output end of an avalanche photodiode (APD). The passband bandwidth of the extremely narrow-band interference circuit is generally not more than 10 MHz, and the transition band is generally less than 20 MHz. It is not affected by the working state of the APD device itself, and can stably provide a wider and continuous frequency domain passband to process avalanche narrow pulse signals. The signal-to-noise ratio, pulse waveform and jitter of the avalanche narrow pulse signal are slightly affected, and the detection efficiency, after-pulse effect and time resolution of the single-photon detector are significantly optimized.

[0100] According to one embodiment of the present invention, the present invention provides a single photon detection device including an interference unit 100, such as Figure 4 As shown, the interference unit 100 includes a signal distribution module 110, a first signal path 120, a second signal path 130, a phase shift module 140 and a coupling module 150. Among them:

[0101] The signal distribution module 110 is configured to divide the input signal into a first signal and a second signal. Optionally, the signal distribution module 110 receives a signal input by an avalanche photodiode, the input signal including an electrical signal generated by the avalanche photodiode in response to incident photons, and also including an interference signal generated by a capacitive response of a gate signal, the frequency of the interference signal being consistent with the gate signal. The signal distribution module 110 divides the input signal into a first signal and a second signal, and transmits them along a first signal path 120 and a second signal path 130, respectively.

[0102] The first signal path 120 is coupled to the signal distribution module 110 and configured to receive and transmit the first signal. Optionally, the signal distribution module 110 divides the input signal into a first signal and a second signal of substantially equal power, and the first signal and the second signal output from the signal distribution module 110 both include an electrical signal generated by the avalanche photodiode in response to incident photons and an interference signal generated by the capacitive response of the gate signal, wherein the first signal is transmitted along the first signal path 120.

[0103] The second signal path 130 is coupled to the signal distribution module 110, and is configured to receive the second signal, filter out the signal of the preset frequency component and transmit it. The second signal output from the signal distribution module 110 is transmitted along the second signal path 130. Optionally, the second signal path 130 includes a narrowband filtering module, and the signal of the preset frequency component in the input signal is filtered and transmitted through the narrowband filtering module. The signal of the preset frequency component is one of the frequency components of the interference signal (hereinafter referred to as "gated interference signal") generated by the capacitive response of the gated signal. For example, if the gated signal is a sinusoidal signal, the gated interference signal has one frequency component. For another example, if the gated signal is a square wave signal, the gated interference signal has multiple frequency components (the Fourier expansion of the square wave signal includes signal components of multiple frequencies).

[0104] The phase shift module 140 is disposed in the first signal path 120 or the second signal path 130 and is configured to shift the phase of the transmission signal by 180°. Figure 4 FIG. 1 shows an implementation in which the phase shift module 140 is disposed in the second signal path 130 . The phase shift module 140 may also be disposed in the first signal path 120 . These implementations are within the protection scope of the present invention. Figure 4 In the illustrated embodiment, the phase shift module 140 shifts the transmission signal of the second signal path 130 , ie, the signal of the preset frequency component, by 180°, and the phase-shifted signal continues to be transmitted along the second signal path 130 .

[0105] The coupling module 150 is coupled to the first signal path 120 and the second signal path 130, and is configured to receive the output signals of the first signal path 120 and the second signal path 130, and output them after coupling. The first signal path 120 receives the first signal and transmits it, wherein the first signal includes the electrical signal generated by the avalanche photodiode in response to the incident photon, and the interference signal generated by the capacitive response of the gated signal. Therefore, the transmission signal of the first signal path 120 includes the electrical signal generated by the avalanche photodiode in response to the incident photon and all the frequency components of the gated interference signal. The second signal path 130 receives the second signal, filters out the signal of the preset frequency component and transmits it, wherein the preset frequency component is one of the frequency components of the interference signal generated by the capacitive response of the gated signal. Therefore, the transmission signal of the second signal path 130 includes one of the frequency components of the gated interference signal. Through the phase shift module 140, the phase of the transmission signal is shifted by 180°. It is assumed that the phase shift module 140 is set in the second signal path 130, and the signal output by the second signal path 130 is one of the frequency components of the gated interference signal, and the frequency signal after the phase shift is 180°. The output signal of the first signal path 120 is coupled with the output signal of the second signal path 130, wherein the signals of the preset frequency component with a phase difference of 180° cancel each other, and the coupling module 150 outputs a full-frequency domain signal after the preset frequency component is canceled, that is, the coupling module 150 outputs the electrical signal generated by the avalanche photodiode in response to the incident photon, and the gated interference signal remaining after the signal of the preset frequency component is filtered out. Optionally, when the gated signal is a sinusoidal signal and the gated interference signal includes only one frequency component, the gated interference signal can be completely filtered out by a single filtering of the interference unit 100.

[0106] According to one embodiment of the present invention, in the interference unit 100 of the single-photon detection device, the difference between the transmission distances of the first signal path 120 and the second signal path 130 is less than a first preset value. The signal distribution module 110 divides the input signal into a first signal and a second signal, wherein the first signal is transmitted along the first signal path 120, and the second signal is transmitted along the second signal path 130. When output from the signal distribution module 110, the initial phases of the first signal and the second signal are the same. During the transmission process, the phase change of the first signal and the second signal depends on the signal transmission time and the module control with the phase shift function. The transmission distances of the first signal path 120 and the second signal path 130 can be set to be equal, that is, the time required for the first signal to be transmitted along the first signal path 120 is the same as the time required for the second signal to be transmitted along the second signal path 130. Optionally, the signal of the preset frequency component is filtered out from the second signal by the narrowband filtering module, and then the signal of the preset frequency component is phase-shifted by 180° by the phase shift module 140. The output signals of the first signal path 120 and the second signal path 130 both include the signal of the preset frequency component. The phase difference of the signal of the preset frequency component when output from the first signal path and the second signal path is exactly 180°, which can be completely offset. The difference in transmission distance between the first signal path 120 and the second signal path 130 is set to be less than a first preset value. The smaller the first preset value is, for example, the signal transmission distances of the first signal path 120 and the second signal path 130 are completely equal, the better the offset effect of the output signal.

[0107] According to one embodiment of the present invention, Figure 5 As shown, in the interference unit 100 of the single-photon detection device, the second signal path 130 further includes a narrowband filtering module 131. Among them:

[0108] The passband bandwidth of the narrowband filtering module 131 is less than or equal to 10 MHz, and the passband of the narrowband filtering module 131 includes the preset frequency component.

[0109] According to an embodiment of the present invention, the narrowband filtering module 131 includes one or more of a surface acoustic wave filter, a bulk acoustic wave filter, and a dielectric filter.

[0110] The single-photon detection device including the interference unit 100 provided by the above-mentioned multiple embodiments of the present invention is filtered through an extremely narrow-band bandpass filter to obtain the fundamental wave or higher harmonic signal frequency component of the gated interference signal, and then interferes with the main transmission signal (including the electrical signal after photoelectric conversion and the gated interference signal) through a coupling module. From the perspective of the entire frequency domain, the interference phenomenon only occurs within the passband and transition band of the extremely narrow-band bandpass filter, so the impact on the main transmission signal is very small. Figure 6 The figure shows the frequency response curve of an extremely narrow bandpass filter.

[0111] According to one embodiment of the present invention, Figure 7 As shown, in the interference unit 100 of the single-photon detection device, the first signal path 120 further includes a power attenuation module 121. Wherein:

[0112] The power attenuation module 121 is configured to adjust the power of the first signal so that the difference between the power of the output signals of the first signal path 120 and the second signal path 130 is smaller than a second preset value.

[0113] The narrowband filter module 131 is arranged in the second signal path 130. The narrowband filter module 131 causes power loss of the signal transmitted by the second signal path 130. The power attenuation module 121 is arranged in the first signal path 120 to correspond to the power loss caused by the narrowband filter module 131 when performing narrowband filtering. The first signal is transmitted through the first signal path 120, and is adjusted by the power attenuation module 121 to attenuate a certain power. The second signal is transmitted through the second signal path 130, and the signal of the preset frequency component is filtered out by the narrowband filter module 131. The filtered signal also has a certain power attenuation. By adjusting the scope of action of the power attenuation module 121, the power difference between the output signals of the first signal path 120 and the second signal path 130 can be made less than the second preset value. The smaller the power difference between the output signals of the first signal path 120 and the second signal path 130, the better the effect of filtering the interference signal of the preset frequency component. For example, if the power of the output signals of the first signal path 120 and the second signal path 130 are equal, the signal power of the preset frequency component is equal and the phase is opposite, which can be effectively offset.

[0114] According to one embodiment of the present invention, the power attenuation module 121 of the interference unit 100 includes one or more of an analog voltage-controlled attenuator (VCA), a digitally controlled step attenuator (DSA), and a resistor network attenuator (the attenuation value can be adjusted by selecting a resistor parameter). The power attenuation module 121 has a wide operating frequency band and is arranged on the first signal path 120 to effectively attenuate the signal within the frequency domain of the first signal (including the electrical signal generated by the avalanche photodiode in response to the incident photon, and the interference signal generated by the capacitive response of the gate signal).

[0115] According to one embodiment of the present invention, in the interference unit 100 of the single-photon detection device, the phase shift module 140 is arranged on the second signal path 130 .

[0116] According to one embodiment of the present invention, the phase shift module 140 in the interference unit 100 includes one or more of a radio frequency transmission line, an analog voltage-controlled phase shifter, a digitally controlled step phase shifter, a capacitor network, an inductor network, and a capacitor-inductor hybrid network phase shifter.

[0117] The phase shift module 140 of the interference unit 100 changes the phase by adjusting the physical length or propagation coefficient of the RF transmission line, or modulates the phase by selecting capacitance / inductance parameters, or modulates the attenuation value by simulating a voltage-controlled capacitor or a digitally controlled stepping capacitor. The phase shift module 140 includes a capacitance or inductance element, or a RF transmission line whose phase shift amount is related to the frequency. Therefore, the phase shift module 140 is set at the output end of the narrowband filter module 131 in the second signal path 130, and the working frequency band of the phase shift module 140 only needs to cover the working passband of the narrowband filter module 131.

[0118] According to one embodiment of the present invention, Figure 8 As shown, the signal distribution module 110 and the coupling module 150 respectively include a three-port radio frequency matching device ( Figure 8 As shown in the figure are three-port RF matching devices 111 and three-port RF matching devices 151), the three-port RF matching devices include a first end, a second end and a third end, wherein:

[0119] The three-port matching device 111 of the signal distribution module 110 is configured as:

[0120] The first end is coupled to the single photon sensing device and configured to receive the input signal;

[0121] The second end is coupled to the first signal path 120 and configured to output the first signal;

[0122] The third end is coupled to the second signal path 130 and configured to output the second signal;

[0123] The three-port matching device 151 of the coupling module 150 is configured as:

[0124] The second end is coupled to the second signal path 130 and configured to receive an output signal of the second signal path 130;

[0125] The third end is coupled to the first signal path 120 and configured to receive an output signal of the first signal path 120;

[0126] The output signal of the first signal path 120 and the output signal of the second signal path 130 are coupled in the three-port RF matching device 151, and the signals of the preset frequency components interfere with each other, and the first end of the three-port RF matching device 151 outputs the coupled signal.

[0127] The three-port RF matching components in the signal distribution module 110 and the coupling module 150 are used symmetrically to eliminate the difference between the two signal paths caused by the imbalance between the ports. For example, the second end of the three-port RF matching component 111 of the signal distribution module 110 is coupled to the first signal path 120 and configured to output the first signal, and the third end is coupled to the second signal path 130 and configured to output the second signal. Due to the difference between the second end and the third end of the three-port RF matching component 111, the power of the first signal and the second signal output by the signal distribution module 110 is also different. In the coupling module 150, the coupling mode of the three-port RF matching device 151 is swapped with the coupling mode of the three-port RF matching device 111, that is, the second end of the three-port RF matching device 151 is coupled to the second signal path 130, configured to receive the output signal of the second signal path 130, and the third end is coupled to the first signal path 120, for receiving the output signal of the first signal path 120. Since the second end and the third end of the three-port RF matching device 151 have the same difference, the signal transmitted through the first signal path 120 and the signal transmitted through the second signal path 130 can be power-corrected before coupling. The difference between the power of the signal transmitted through the first signal path 120 and the signal transmitted through the second signal path 130 is less than the preset value, so that the interference signal of the preset frequency component is largely eliminated after passing through the interference unit 100.

[0128] According to one embodiment of the present invention, in the interference unit 100, the three-port RF matching device includes a directional coupler, and the second end and the third end of the directional coupler have a preset signal isolation. The second end of the directional coupler of the signal distribution module 110 is coupled to the first signal path 120 and configured to output the first signal; the third end is coupled to the second signal path 130 and configured to output the second signal; the second end of the directional coupler of the coupling module 150 is coupled to the second signal path 130 and configured to receive the output signal of the second signal path 130; the third end is coupled to the first signal path 120 and is used to receive the output signal of the first signal path 120. The second end and the third end of the directional coupler have a preset isolation to reduce the reflection of the signal transmitted in the first signal path 120 or the second signal path 130 into the second signal path 130 or the first signal path 120.

[0129] According to one embodiment of the present invention, Fig. 9 As shown, the present invention provides a single photon detection device 200 including the interference unit 100 described above, and the single photon detection device 200 further includes: a single photon sensing device 210, a DC voltage source 220 and a gate signal generator 230. Wherein:

[0130] The single-photon sensing device 210 is configured to receive an optical signal and convert it into an electrical signal for output. Optionally, the single-photon sensing device 210 includes an avalanche photodiode. The avalanche photodiode operates under the action of reverse bias. When there is no incident photon, the reverse current is extremely weak, called dark current; when there is incident photon, the reverse current increases rapidly, called photocurrent. The greater the intensity of light, the greater the reverse current, that is, the avalanche photodiode converts the optical signal into an electrical signal for output.

[0131] The DC voltage source 220 is coupled to the single photon sensing device 210 and is configured to provide a DC bias voltage to the single photon sensing device 210. The DC voltage source 220 applies a DC bias voltage to the single photon sensing device 210 to put it in a critical breakdown state.

[0132] The gating signal generator 230 is coupled to the single-photon sensing device 210 and is configured to provide a gating signal to the single-photon sensing device 210. On the basis of applying a DC bias, the gating signal generator 230 applies a periodically changing gating signal to the single-photon sensing device 210. Optionally, the gating signal applied by the gating signal generator 230 to the single-photon sensing device 210 includes a periodic signal, such as one or more of a sinusoidal signal, a square wave signal, and a triangular wave signal. Within half a cycle of the gating signal, the single-photon sensing device 210 is in an avalanche breakdown state, and an avalanche can occur upon receiving a light signal at the single-photon level, and an avalanche current is output; within the other half cycle of the gating signal, the single-photon sensing device 210 cannot respond to the incident light signal, thereby reducing the avalanche charge and the recovery time after the avalanche. Wherein:

[0133] The interference unit 100 receives an input signal, where the input signal includes the electrical signal generated after the single-photon sensing device 210 performs photoelectric conversion and an interference signal generated by the capacitive response of the gate signal.

[0134] According to one embodiment of the present invention, the gated signal described above includes a periodic signal, such as one or more of a sine signal, a square wave signal, and a triangular wave signal. The second signal path 130 filters and transmits the signal of a preset frequency component in the input signal through a narrowband filter module 131. The signal of the preset frequency component is one of the frequency components of the interference signal generated by the capacitive response of the gated signal. For example, if the gated signal is a sine signal, the gated interference signal has one frequency component. For another example, if the gated signal is a square wave signal, the gated interference signal has multiple frequency components (the Fourier expansion of the square wave signal includes signal components of multiple frequencies).

[0135] The interferometer unit 100 of the single photon detection device provided by the above-mentioned embodiments of the present invention has a typical frequency response curve as shown in FIG. Fig. 10A , Fig. 10B As shown. Fig. 10B for Fig. 10A From the effect diagram of adjusting the coordinate axis zoom (Zoom In), it can be seen that the interference phenomenon occurs within the passband and transition band of the extremely narrow bandpass filter. From the perspective of the entire frequency domain, the impact on the output signal is very small.

[0136] According to one embodiment of the present invention, Fig.11 As shown, the present invention provides a single photon detection device 200, comprising a plurality of interference units 100 as described above.

[0137] A plurality of interference units 100 are cascaded, and the second signal path 130 of each interference unit 100 filters out a signal corresponding to one of the frequency components of the gated signal.

[0138] The present invention can filter out multiple frequency components in the gated interference signal one by one by setting a multi-stage interference unit 100.

[0139] The gated signal, whether it is a periodic signal waveform such as a sine wave, a square wave, or a triangle wave, is a linear combination of its fundamental frequency component and its higher harmonic frequency component. By configuring the operating frequency and number of the interference units 100, for example, selecting two interference units 100 to work at the fundamental frequency of the gated signal, one interference unit 100 to work at the second harmonic frequency of the gated signal, and one interference unit 100 to work at the third harmonic frequency of the gated signal, most of the signals in the gated interference signal can be filtered out.

[0140] Fig.12 The single photon detection device 200 provided by the present invention includes an interference unit 100, and the signal waveform outputted after the gated interference signal is filtered out by the multi-stage interference unit 100. Figure 3 Compared with the signal waveform in FIG. 1 , the electrical signal generated by the single-photon sensing device 210 in response to the incident photon is easy to read.

[0141] According to one embodiment of the present invention, Fig.13 As shown, the single photon detection device 200 provided by the present invention further comprises:

[0142] A plurality of signal amplifying units 240, each of which is disposed before one of the interference units 100 along the transmission direction of the input signal, is configured to amplify the input signal and pre-process the signal input to the interference unit 100 to prepare for subsequent narrowband filtering. Fig.13, it is shown that the single-photon detection device 200 includes two-stage interference units 100, and an amplification unit 240 is arranged before each stage interference unit 100 along the transmission direction of the input signal. It is easy for those skilled in the art to understand that the single-photon detection device 200 can also include more or less interference units 100, and thus correspond to more or less amplification units 240; the single-photon detection device 200 can also include a first-stage interference unit 100 and an amplification unit 240 arranged before the first-stage interference unit 100 along the transmission direction of the input signal. The above variations are all within the protection scope of the present invention.

[0143] According to one embodiment of the present invention, Fig.14 As shown, the single photon detection device 200 provided by the present invention further includes: a low-pass filtering unit 250.

[0144] The low-pass filter unit 250 is disposed after the plurality of interference units 100 along the transmission direction of the input signal, and is configured to perform low-pass filtering on the signals output after being filtered by the plurality of interference units 100 . Fig.14 The single photon detection device 200 is shown to include a two-stage interference unit 100, and a low-pass filter unit 250 is arranged after the two-stage interference unit 100 along the transmission direction of the input signal. It is easy to understand for those skilled in the art that the single photon detection device 200 can include more or less interference units 100.

[0145] As described above, in one embodiment, by configuring two interference units 100 to work at the fundamental frequency of the gated signal, one interference unit 100 to work at the second harmonic frequency of the gated signal, and one interference unit 100 to work at the third harmonic frequency of the gated signal, most of the signals in the gated interference signal can be filtered out. A low-pass filter unit 250 is arranged after the above-mentioned four-stage interference unit 100, and the operating frequency of the low-pass filter unit 250 can be selected to be slightly lower than the fourth harmonic frequency of the gated signal to further filter out the fourth harmonic frequency component in the gated interference signal.

[0146] According to an embodiment of the present invention, in the single-photon detection device 200, the number and parameters of the signal amplification unit 240 and the low-pass filtering unit 250 can be configured according to actual needs.

[0147] According to one embodiment of the present invention, the present invention further provides a chip, on which the single photon detection device provided by one or more of the above embodiments is integrated.

[0148] According to one embodiment of the present invention, Fig.15As shown, the present invention further provides a method 10 for performing single photon detection using the single photon detection device provided by one or more of the above embodiments, comprising steps S101 to S108.

[0149] In step S101, a DC bias voltage is provided to a single-photon sensing device through a DC voltage source, so that the single-photon sensing device is in a critical breakdown state.

[0150] In step S102, a gating signal generator is used to provide a gating signal to the single-photon sensing device.

[0151] In step S103, the optical signal is received by the single-photon sensing device and converted into an electrical signal.

[0152] In step S104, the input signal is divided into a first signal and a second signal by the signal distribution module, wherein the input signal includes the electrical signal and an interference signal generated by the capacitance response of the gate signal.

[0153] In step S105, the first signal is received and transmitted through the first signal path.

[0154] In step S106, the second signal is received through the second signal path, and a signal of a preset frequency component is filtered out and transmitted.

[0155] In step S107, the phase of the transmission signal is shifted by 180° by the phase shift module.

[0156] In step S108, the output signals of the first signal path and the second signal path are received by the coupling module and output after coupling.

[0157] According to an embodiment of the present invention, in the method 10 for single photon detection, the difference between the transmission distances of the first signal path and the second signal path is less than a first preset value.

[0158] According to one embodiment of the present invention, in a method 10 for single photon detection, wherein the second signal path comprises: a narrowband filtering module, the passband of the narrowband filtering module comprises the preset frequency component, and the passband bandwidth of the narrowband filtering module is less than or equal to 10 MHz, the method 10 further comprises:

[0159] The second signal is filtered by the narrowband filtering module.

[0160] According to one embodiment of the present invention, in the method 10 for single photon detection, the first signal path includes: a power attenuation module; the method 10 further includes:

[0161] The power of the first signal is adjusted by the power attenuation module so that the difference between the power of the output signals of the first signal path and the second signal path is smaller than a second preset value.

[0162] According to one embodiment of the present invention, in a method 10 for single-photon detection, the signal distribution module and the coupling module respectively include a three-port radio frequency matching device, and the three-port radio frequency matching device includes a first end, a second end and a third end, wherein the three-port matching device of the signal distribution module is configured as follows: the first end is coupled to the single-photon sensing device, the second end is coupled to the first signal path, and the third end is coupled to the second signal path; the three-port matching device of the coupling module is configured as follows: the second end is coupled to the second signal path, and the third end is coupled to the first signal path, and the method 10 further includes:

[0163] Receiving the input signal through a first end of a three-port radio frequency matching device of the signal distribution module;

[0164] Outputting the first signal through the second end of the three-port radio frequency matching device of the signal distribution module;

[0165] Outputting the second signal through a third terminal of the three-port radio frequency matching device of the signal distribution module;

[0166] receiving the output signal of the second signal path through the second end of the three-port radio frequency matching device of the coupling module;

[0167] receiving the output signal of the first signal path through the third terminal of the three-port radio frequency matching device of the coupling module;

[0168] The output signal of the first signal path is coupled with the output signal of the second signal path through the first end of the three-port radio frequency matching device of the coupling module, and the signal is output.

[0169] According to one embodiment of the present invention, in a method 10 for single photon detection, the single photon detection device further comprises a plurality of interference units, and the plurality of interference units are cascaded; the preset frequency component comprises one of the frequency components of the gating signal; the method 10 further comprises:

[0170] An interference signal corresponding to one of the frequency components of the gated signal is filtered out through the second signal path of each interference unit.

[0171] According to one embodiment of the present invention, in a method 10 for single photon detection, wherein the single photon detection device further comprises a plurality of signal amplification units, each of the signal amplification units being arranged before one of the interference units along the transmission direction of the input signal, the method 10 further comprises:

[0172] The input signal is amplified by the multiple signal amplification units.

[0173] According to one embodiment of the present invention, in a method 10 for single photon detection, wherein the single photon detection device further comprises a low-pass filtering unit, which is arranged after the plurality of interference units along the transmission direction of the input signal, the method 10 further comprises:

[0174] The output signal filtered by the plurality of interference units is subjected to low-pass filtering by the low-pass filtering unit.

[0175] The specific limitations of the above-mentioned method 10 for single-photon detection are similar to the specific limitations in the aforementioned single-photon detection device including the interference unit 100. Please refer to the above introduction to the single-photon detection device including the interference unit 100, and will not be repeated here.

[0176] The single-photon detection device including the interference unit 100 and the method 10 for performing single-photon detection provided by the present invention are verified by experimental verification as follows:

[0177] Experiment 1: Avalanche photodiode is used as a single-photon sensing device, and the gate signal adopts a 1.25GHz square wave signal, with a total of four-level interference units. Among them, the operating frequency of the two-level interference unit is 1.25GHz, the operating frequency of the first-level interference unit is 2.5GHz, and the operating frequency of the first-level interference unit is 3.75GHz. A low-pass filter unit is set after the four-level interference unit, and the operating frequency is 4.5GHz. The attenuation module adopts a resistor network, the phase shift module adopts a capacitor network, the narrowband filter module adopts a surface acoustic wave filter (SAW), and the signal distribution module and coupling module adopt a directional coupler.

[0178] Experiment 2: Avalanche photodiode is used as a single-photon sensing device. The gate signal uses a 1.25GHz sine wave signal, and a two-stage interference unit is set up. The operating frequency of the two-stage interference unit is 1.25GHz. A low-pass filter unit is set after the two-stage interference unit, and the operating frequency is configured to be 2.1GHz. The narrowband filter module uses a surface acoustic wave filter (SAW), the attenuation module uses a coaxial resistor network attenuator, and the phase shift module uses an RF transmission line of appropriate length.

[0179] The experimental results of the two experiments show that the gated interference signal is filtered out in large quantities, and the electrical signal after photoelectric conversion can be effectively extracted, with obvious optimization effects on the post-pulse effect, time resolution, and photon counting rate within the overall frequency range.

[0180] Fig.16A The schematic diagram of the device structure used in Experiment 2 of the above experiment is shown. The gated signal is a 1.25GHz sine wave signal, UNIC1 is a first-stage interference unit, and its operating frequency is 1.25GHz, and UNIC2 is a second-stage interference unit, and its operating frequency is 1.25GHz. AMP1 and AMP2 are signal amplifiers respectively arranged before the interference units UNIC1 and UNIC2 along the signal transmission direction. LF1 is a low-pass filter arranged after the interference unit UNIC2 along the signal transmission direction, and its operating frequency is 2.1GHz. Along the signal transmission direction, a first-stage signal amplifier AMP3 is arranged before the low-pass filter LF1, and a high-speed discriminator DISC1 is arranged after the low-pass filter LF1 to discriminate the output signal before outputting it.

[0181] Fig. 16B The histogram of the detection events of the single photon detection device in Experiment 2 of the above experiment is shown. The detection efficiency in the figure is 29%, the after pulse is 1.3%, the dark count is 3kcps, and the temperature is 263K. The peak values ​​of each counting gate in the figure are steep, indicating that this device has good time resolution.

[0182] The present invention also provides a non-transitory computer-readable storage medium having computer-readable instructions stored thereon. When the instructions are executed by a processor, the processor executes the method 10 described in one or more of the above embodiments.

[0183] The single-photon detection device, electrical chip and method for single-photon detection provided by the present invention include an interference unit, and the fundamental or higher harmonic signal frequency component of the gated interference signal is obtained by filtering through an extremely narrow bandpass filter, and then interferes with the main transmission signal (including the electrical signal after photoelectric conversion and the gated interference signal) through a coupling module. The interference phenomenon only occurs in the passband and transition band of the extremely narrow bandpass filter from the perspective of the entire frequency domain, so the impact on the main transmission signal is very small. Through multi-stage filtering, a large number of gated interference signals are effectively eliminated, and a relatively wide and continuous frequency domain passband can be stably provided to process avalanche narrow pulse signals, which has little impact on the signal-to-noise ratio, pulse waveform and jitter of the avalanche narrow pulse signal, and has a significant optimization effect on the detection efficiency, post-pulse effect and time resolution of the single-photon detector.

Claims

1. A single photon detection device, comprising an interference unit, characterized in that: The interference unit comprises: a signal distribution module configured to divide an input signal into a first signal and a second signal; A first signal path, coupled to the signal distribution module, configured to receive the first signal and transmit; A second signal path is coupled to the signal distribution module and configured to receive the second signal, filter out a signal of a preset frequency component from the second signal, and transmit the signal; a phase shift module, disposed in the first signal path or the second signal path, configured to shift the phase of the transmission signal by 180°; The coupling module is coupled to the first signal path and the second signal path, and is configured to receive output signals of the first signal path and the second signal path and output them after coupling.

2. The single-photon detection device as described in claim 1, wherein the difference between the transmission distances of the first signal path and the second signal path is less than a first preset value.

3. The single photon detection device according to claim 1 or 2, wherein the second signal path comprises: A narrowband filtering module, wherein the passband of the narrowband filtering module includes the preset frequency component. 4 . The single-photon detection device as claimed in claim 3 , wherein the passband bandwidth of the narrowband filter module is less than or equal to 10 MHz. 5 . The single-photon detection device as claimed in claim 3 , wherein the narrow-band filtering module comprises one or more of a surface acoustic wave filter, a bulk acoustic wave filter, and a dielectric filter.

6. The single photon detection device according to claim 1 or 2, wherein the first signal path comprises: The power attenuation module is configured to adjust the power of the first signal so that the difference between the power of the output signals of the first signal path and the second signal path is smaller than a second preset value. 7 . The single-photon detection device as described in claim 6 , wherein the power attenuation module comprises one or more of an analog voltage-controlled attenuator, a digitally controlled step attenuator, and a resistor network attenuator.

8. The single-photon detection device as described in claim 1 or 2, wherein the phase shift module is arranged on the second signal path.

9. The single-photon detection device as described in claim 8, wherein the phase shift module includes one or more of a radio frequency transmission line, an analog voltage-controlled phase shifter, a digitally controlled step phase shifter, a capacitor network phase shifter, an inductor network phase shifter, and a capacitor-inductor hybrid network phase shifter.

10. The single-photon detection device according to claim 1 or 2, wherein the signal distribution module and the coupling module respectively include a three-port radio frequency matching device, the three-port radio frequency matching device includes a first end, a second end and a third end, and the three-port radio frequency matching device of the signal distribution module is configured as: The first end is coupled to the single photon sensing device and configured to receive the input signal; The second end is coupled to the first signal path and configured to output the first signal; The third terminal is coupled to the second signal path and configured to output the second signal; The three-port RF matching device of the coupling module is configured as follows: The second end is coupled to the second signal path and configured to receive an output signal of the second signal path; The third terminal is coupled to the first signal path and configured to receive an output signal of the first signal path; The first end outputs a signal after coupling the output signal of the first signal path and the output signal of the second signal path. 11 . The single-photon detection device according to claim 10 , wherein the three-port radio frequency matching device comprises a directional coupler, and the second end and the third end of the directional coupler have a preset signal isolation degree.

12. The single photon detection device according to claim 1 or 2, further comprising: A single photon sensing device configured to receive an optical signal and convert it into an electrical signal for output; a DC voltage source coupled to the single-photon sensing device and configured to provide a DC bias voltage to the single-photon sensing device so as to put the single-photon sensing device in a critical breakdown state; A gating signal generator is coupled to the single-photon sensing device and is configured to provide a gating signal to the single-photon sensing device; wherein The input signal includes the electrical signal and an interference signal generated by a capacitance response of the gate signal. 13 . The single-photon detection device according to claim 12 , wherein the gating signal comprises a periodic signal, and the preset frequency component comprises one frequency component of the gating signal.

14. The single photon detection device according to claim 13, comprising a plurality of said interference units, wherein: A plurality of the interference units are cascaded, and the second signal path of each interference unit filters out an interference signal corresponding to one of the frequency components of the gated signal.

15. The single photon detection device according to claim 14, further comprising: A plurality of signal amplifying units, each of which is disposed before one of the interference units along the transmission direction of the input signal, and is configured to amplify the input signal.

16. The single photon detection device according to claim 14 or 15, further comprising: The low-pass filtering unit is arranged behind the plurality of interference units along the transmission direction of the input signal, and is configured to perform low-pass filtering on the output signals filtered by the plurality of interference units.

17. A chip, characterized in that: The invention comprises a single photon detection device according to any one of claims 1 to 16 integrated thereon.

18. A method for single photon detection using the single photon detection device according to any one of claims 1 to 16, characterized in that: include: Providing a DC bias voltage to the single-photon sensing device through a DC voltage source, so that the single-photon sensing device is in a critical breakdown state; Providing a gating signal to the single-photon sensing device through a gating signal generator; Receiving the optical signal through the single-photon sensing device and converting it into an electrical signal; The input signal is divided into a first signal and a second signal by the signal distribution module, wherein the input signal includes the electrical signal and an interference signal generated by the capacitance response of the gate signal; receiving and transmitting the first signal through the first signal path; receiving the second signal through the second signal path, filtering out a signal of a preset frequency component from the second signal and transmitting the signal; The phase of the transmission signal is shifted by 180° by the phase shift module; The output signals of the first signal path and the second signal path are received by the coupling module and output after coupling.

19. The method of claim 18, wherein a difference between transmission distances of the first signal path and the second signal path is less than a first preset value.

20. The method according to claim 18 or 19, wherein the second signal path comprises a narrowband filtering module, the passband of the narrowband filtering module comprises the preset frequency component, and the passband bandwidth of the narrowband filtering module is less than or equal to 10 MHz, the method further comprising: The second signal is filtered by the narrowband filtering module.

21. The method of claim 18 or 19, wherein the first signal path comprises a power attenuation module; the method further comprising: The power of the first signal is adjusted by the power attenuation module so that the difference between the power of the output signals of the first signal path and the second signal path is smaller than a second preset value.

22. The method according to claim 18 or 19, wherein the signal distribution module and the coupling module respectively comprise a three-port radio frequency matching device, the three-port radio frequency matching device comprises a first end, a second end and a third end, wherein: The three-port matching device of the signal distribution module is configured as follows: the first end is coupled to the single-photon sensing device, the second end is coupled to the first signal path, and the third end is coupled to the second signal path; the three-port matching device of the coupling module is configured as follows: the second end is coupled to the second signal path, and the third end is coupled to the first signal path, and the method further includes: Receiving the input signal through a first end of a three-port radio frequency matching device of the signal distribution module; Outputting the first signal through the second end of the three-port radio frequency matching device of the signal distribution module; Outputting the second signal through a third terminal of the three-port radio frequency matching device of the signal distribution module; receiving the output signal of the second signal path through the second end of the three-port radio frequency matching device of the coupling module; receiving the output signal of the first signal path through the third terminal of the three-port radio frequency matching device of the coupling module; The output signal of the first signal path is coupled with the output signal of the second signal path through the first end of the three-port radio frequency matching device of the coupling module, and the signal is output.

23. The method according to claim 18 or 19, wherein the single photon detection device comprises a plurality of the interference units, and the plurality of interference units are cascaded; the preset frequency component comprises one of the frequency components of the gating signal; and the method further comprises: An interference signal corresponding to one of the frequency components of the gated signal is filtered out through the second signal path of each interference unit.

24. The method of claim 23, wherein the single photon detection device further comprises a plurality of signal amplification units, each of the signal amplification units being disposed before one of the interference units along the transmission direction of the input signal, the method further comprising: The input signal is amplified by the multiple signal amplification units.

25. The method of claim 23, wherein the single photon detection device further comprises a low-pass filtering unit disposed after the plurality of interference units along the transmission direction of the input signal, the method further comprising: The output signal filtered by the plurality of interference units is subjected to low-pass filtering by the low-pass filtering unit.

26. A non-transitory computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of claims 18 to 25.

Images