47results about How to "Reduce dark count" patented technology

The invention discloses an integrated gating active quenching / restoring circuit. The integrated gating active quenching / restoring circuit comprises a quick detection circuit, a pulse generation circuit, a pixel control circuit, a quenching circuit and a restoring circuit, wherein the quick detection circuit is used for processing a detected anode current signal of an SPAD (Single Photon Avalanche Diode) into a pulse signal, the pulse signal can be output through the pulse generation circuit, the pixel control circuit is controlled by an output signal and a gating signal of the pulse generation circuit, the restoring circuit and the quenching circuit are respectively controlled by outputs of the pixel generation circuit, outputs of the restoring circuit and the quenching circuit can be fed back to an anode of the SPAD, and the restoring and the quenching of the SPAD can be controlled. According to the integrated gating active quenching / restoring circuit disclosed by the invention, by adopting a gating control method, the dark counting rate of the SPAD can be effectively reduced, the quenching time can be controlled by the pulse generation circuit, and the integrated gating active quenching / restoring circuit has the advantages of compact area and low power consumption.

The invention relates to a single photon counting and imaging detection device. A high-voltage power supply of the device is connected with a micro-imaging reinforced tube through a high tension lead; a display, an image processing device and a printer are connected with a computer respectively; an anode collector is arranged between the micro-imaging reinforced tube and a preamplifier; the anode collector comprises a substrate, an electrode plated on the substrate and a signal lead; an anode is connected with the preamplifier through the signal lead; and the micro-imaging reinforced tube comprises a photocathode and a microchannel plate connected with the photocathode which are arranged sequentially along a light path. The device has the characteristics that the device can read out a time mark for arriving time and a general image of integral in a period, realize the single photon counting and two-dimensional imaging detection of an extremely-weak object, has the function of single photon counting, and can perform two-dimensional imaging on the extremely-weak luminous object. The device has the advantages of large area array, high sensitivity, low dark count, high resolution factor, good imaging linearity and the real-time measurement and processing.

The invention relates to the fields of quantum secret communication, weak ultrared detection, and the like, and provides an impulse gate-control low-pass filtering ultrared single-photon detector. Theimpulse gate-control low-pass filtering ultrared single-photon detector comprises an impulse gate-control power source, an In-Ga-As-In-P avalanche photodiode circuit, a DC voltage baising circuit, alow-pass filter, a high-speed wideband amplifier, a ultra-high-speed comparator and a counter, wherein gigahertz (GHz) impulse signals output by the impulse gate-control power source are used as gatecontrol signals of the In-Ga-As-In-P avalanche photodiode circuit, and spike noise signals caused by the junction capacitance differential effect of In-Ga-As-In-P avalanche photodiodes by the low-passfilter are used for filtering in a low-pass mode. The gigahertz impulse gate-control low-pass filtering ultrared single-photon detector solves the problem of spike noise interference in the prior art, increases the detection sensitivity of the avalanche signals and can be used for detecting GHz high-speed ultrared photon.

The invention provides a single-photon avalanche diode quenching circuit based on an offset control differential amplification structure. A gate control circuit is used for receiving a gate control enable signal input externally to be in the closed or opened state. A rapid reset circuit is used for receiving a reset signal input externally while the gate control circuit is in the opened state so that the gate control circuit can be in the closed state. When an SPAD detects that a photon generates avalanche current, the avalanche current flows through a detection resistor to generate voltage drop. A low voltage detection circuit adopts the differential amplification structure based on offset control and is used for inducting changes of the input end voltage; when the input end voltage is larger than a detection threshold value of the low voltage detection circuit, output end signals become low-level signals, the detection resistor is controlled to be switched off, and meanwhile a rapid quenching circuit is closed; the rapid quenching circuit is used for accelerating the quenching process when closed, so that the avalanche current is quenched. In the quenching circuit, the detection threshold value of the quenching circuit can be smaller than the turn-on voltage of an NMOS transistor.

The invention provides a high polarization ratio single photon detector based on superconductive nanowires. The high polarization ratio single photon detector based on the superconductive nanowires comprises a substrate, an anti-reflection layer and the superconductive nanowires, wherein the anti-reflection layer is combined to the surface of the substrate, the superconductive nanowires are combined to the surface of the anti-reflection layer in a periodic winding structure, the width of the superconductive nanowires is not larger than 75 nanometers, the thickness is not larger than 7 nanometers, and the duty ratio is not larger than 40 percent. According to the high polarization ratio single photon detector based on the superconductive nanowires, the width, the thickness and the duty ratio of the superconductive nanowires of the single photon detector are adjusted, and a large polarization ratio of the single photon detector is achieved. Compared with a traditional polarization detector, the high polarization ratio single photon detector based on the superconductive nanowires has the advantages of being small in size, simple in structure, high in sensitivity, low in dark counting and the like, and external integration of polarization devices is not needed.

The invention discloses an optical fiber temperature and strain sensing device based on a high spectral resolution technology. The optical fiber temperature and strain sensing device comprises an optical transmitting system, an optical fiber sensing system, a high spectral resolution scanning system, an optical filtering system, a data acquisition system and a control system. The invention further discloses an optical fiber temperature and strain sensing method based on a high spectral resolution technology. According to the invention, temperature and strain carriers based on optical fiber brillouin scattering are used for the distributed sensing of temperature and strain; a narrowband reflective tunable Bragg grating is used for filtering out optical fiber brillouin back scattering, a cavity length-tunable Fabry-Perot interferometer is used for the full spectrum scanning of optical fiber brillouin scattering spectrum, a single photon technology is used for detecting a back brillouin scattering signal in the optical fiber; the invention has the advantages that the structure is simple, s the stability is high, compared with coherent detection, the signal detection and processing difficulty and complexity are reduced, and the detection distance resolution and accuracy are improved.

The invention discloses high atmosphere detection laser radar based on a large-photosurface superconducting single-photon detector. By application of the large-photosurface superconducting single-photon detector to a high atmosphere detection laser radar system, high atmosphere parameter detection can be realized through increase of telescope area. Compared with an existing detector applied to the high atmosphere detection laser radar, the superconducting single-photon detector has advantages of large photosurface, high counting rate, high quantum efficiency, low dark count rate, high photon count rate and short jittering time. Therefore, the high atmosphere detection laser radar based with the large-photosurface superconducting single-photon detector is more advantageous in range resolution, spatial resolution and detection precision; in other words, under the condition of realizing same detection indexes, the laser radar with the large-photosurface superconducting single-photon detector can adopt a smaller-aperture telescope or a lower-power laser.

The invention belongs to the technical field of communication, and discloses a self-cancellation single photon detection system. The system comprises a mixer, an avalanche photodiode APD, a trans-impedance amplifier TIA, a sample resistor R and a comparator. A negative electrode of the avalanche photodiode APD is connected with a direct-current bias VD, and a positive electrode is grounded through the sample resistor; a positive electrode of the avalanche photodiode APD is connected with an input end of the trans-impedance amplifier TIA; an output end of the trans-impedance amplifier TIA is connected with a negative electrode of the avalanche photodiode APD and the comparator respectively; a single photon signal to be tested and a local oscillator light signal are mixed by the mixer, then an optical signal is output, and the optical signal is sent to a light input end of the avalanche photodiode APD; an output signal of the trans-impedance amplifier TIA feeds back and adjusts the voltage across two ends of the avalanche photodiode APD; and the comparator counts the pulse of the single photon. The self-cancellation single photon detection system provided by the invention is high efficiency, convenient and reliable.

A biological flow type analyzer relates to an analyzer, in particular to a biological flow type analyzer and application thereof. The present invention provides a biological flow type analyzer high in sensitivity, comprising an optical system, a liquid flow system and a detection system, wherein the optical system is provided with an optical platform, a solid-state laser, a translation table, a continuous-adjustable attenuator, a reflecting mirror, an achromatic scuffing lens, a quartz circulating pool, a first aspheric lens, a second aspheric lens, a third aspheric lens, a first optical filter, a second optical filter and a third optical filter; the liquid flow system is provided with a nitrogen cylinder, a triple valve, a first switch valve, a second switch valve, a third switch valve, a fourth switch valve, a pressure regulator, a pressure sensor, a four-way valve, an injector, a quartz capillary tube, a sample tube, a sample injector, a sheath liquid bottle and a waste liquid bottle; the detection system is provided with a first detector, a second detector, a translation table, a data acquisition card and signal acquisition software.

The invention discloses a near-infrared band low-noise free-running single-photon detector, and the detector comprises a negative feedback avalanche photodiode (NFAD), a peripheral circuit of the NFAD, a refrigeration box, a discrimination module, a dead time setting module, a temperature adjustment module and an FPGA; The NFAD and the peripheral circuit are respectively connected with the FPGA through the discrimination module and the dead time setting module. The discrimination module is used for converting an avalanche signal into an electrical level signal and transmitting the electrical level signal to the FPGA. The dead time setting module is used for reducing the bias voltage of the NFAD below an avalanche voltage. The NFAD and the peripheral circuit are packaged in the refrigeration box, and the refrigeration box is connected with the FPGA through the temperature adjustment module. According to the scheme of the invention, the detector carries out the deep refrigeration of the NFAD through a Stirling refrigerator, thereby reducing the dark count of the detector. The post-pulse probability of the detector is effectively inhibited through integrating a single thin resistor in a detector part and setting the dead time after each detection event.

The invention provides a wavelength up-conversion semiconductor structure and an optical detection method thereof, belonging to the semiconductor material and device preparation field. The wavelength up-conversion semiconductor structure is characterized in that: the wavelength up-conversion semiconductor comprises at least two quantum well layers and a barrier layer between the two layers, energy difference between an electrical excitation state energy level in a quantum well layer-1 and an electrical ground state energy level is corresponding to infrared photon energy, and energy differencebetween an electrical ground state energy level in a quantum well layer-2 and the electrical excitation state energy level in the quantum well layer-1 is less than 50meV. According to the invention, a dark count introduced in a wavelength up-conversion process can be greatly reduced. The invention provides an infrared low-light detection method based on the wavelength up-conversion semiconductor structure, and is characterized in that: when an infrared photon is absorbed, an electron at a ground state energy level in the quantum well layer-1 moves to an excitation state energy level and enters the quantum well layer-2 through resonance tunneling, and an electron cavity carries out recombination emission of a low wave length photon which can be detected by an optical detector with an extremely dark count.

The invention discloses an avalanche photodetector based on an arc diffusion region and a manufacturing method of the avalanche photodetector. The avalanche photodetector comprises an epitaxial structure, a passivation layer, a P type electrode layer, an N type electrode layer, and an antireflection film, wherein the epitaxial structure comprises an N-type substrate, an absorption layer, a chargelayer and an intrinsic multiplication layer from the bottom up; a 3D bowl-shaped opening is formed in the intrinsic multiplication layer, and a P-type highly-doped arc-shaped diffusion region is formed under the 3D bowl-shaped opening; the passivation layer formed on the epitaxial structure; the P-type electrode layer is in contact with the P-type highly-doped arc-shaped diffusion region; the N-type electrode layer is in contact with the N-type substrate; the antireflection film, which serves as a light window, is arranged on the front surface or the back surface of the single-electron avalanche photodetector; the connecting line of the center of the antireflection film and the curvature center of the arc-shaped diffusion area is parallel to the extension direction; and the light field central area of the light window coincides with a high field area in space. According to the avalanche photodetector, the photon detection efficiency of the device is effectively improved, the dark countof the device is reduced, and the probability of the post pulse is reduced.

The invention discloses a vacuum-semiconductor hybrid photoelectric detector. The vacuum-semiconductor hybrid photoelectric detector includes an input light window, a photoelectric cathode, a ceramic ring, a focusing device, a semiconductor detector, an anode pedestal and a signal output apparatus, wherein the photoelectric cathode is fixed on the input light window; the semiconductor detector is fixed on the signal output apparatus; the signal output apparatus is fixed on the anode pedestal; the focusing device is arranged between the photoelectric cathode and the semiconductor detector; and distance control and insulation can be realized through the ceramic ring between the input light window and the focusing device, and between the focusing device and the anode pedestal. The vacuum-semiconductor hybrid photoelectric detector organically integrates a vacuum device with a semiconductor device, and has the advantages of being large in the detection photosensitive area, being flexible in response to spectrum, being high in the response speed, being large in the dynamic range, being high in gain, being low in dark count, being simple in processing, being convenient in assembling, being low in cost, and being high in reliability.

The present invention proposes a single-photon Si-APD detector, comprising: an absorption region, a P+ contact region, an N+ contact region, an avalanche region, and a dielectric layer. The middle part of the surface of the P-type substrate is provided with an absorption region. A P+ contact area is provided, and a lower electrode is provided below the P+ contact area; stop rings are provided at both ends of the upper part of the absorption area; an avalanche area is provided in the middle of the upper part of the absorption area, and the avalanche area is composed of P-type impurities Formed by compensating doping with N-type impurities; an N+ contact region is arranged above the avalanche region; a guard ring is arranged on both sides of the avalanche region, and an upper electrode is arranged above the guard ring; an N+ contact region is arranged above the N+ contact region medium layer. The single-photon Si-APD detector has a wide avalanche region and few defects introduced in the manufacturing process, which can achieve high detection efficiency and low dark count device performance.

The invention provides a single-photon Si-APD detector, which comprises an absorption region, a P+ contact region, an N+ contact region, an avalanche region and a dielectric layer. The absorption region is arranged in the middle of the surface of a P-type substrate; the P+ contact region is arranged under the absorption region; and a lower electrode is arranged under the P+ contact region. Cut-offrings are arranged at the two ends of the upper portion of the absorption region. The avalanche region is arranged in the middle of the upper portion of the absorption region and is formed through compensation doping of P-type impurities and N-type impurities. The N+ contact region is arranged on the avalanche region. The two sides of the avalanche region are each provided with a protection ring,and an upper electrode is arranged above the protection ring. The dielectric layer is arranged on the N+ contact region. The single-photon Si-APD detector has the relatively wide avalanche region andintroduces few defects in the manufacturing process, and can realize device performance of high detection efficiency and low dark counting.

The invention discloses an NP-type single-photon avalanche diode (SPAD) based on a CMOS image sensor technology. Its basic structure includes: a deep N well is arranged above a P-type silicon substrate; a P well is formed above the deep N well; There is a lightly doped guard ring; the N+ region is formed above the P well and has a certain overlap with the guard ring; a PN junction is formed between the N+ and the P well, and the cathode electrode and the anode electrode are drawn out through N+ and P+; the N+ region and A heavily doped P-type region is set above the guard ring; a P well is set around the guard ring and the substrate electrode is drawn out through P+. The single photon avalanche diode of the present invention can reduce the dark count caused by the interface defect of the NP-type SPAD device by making a heavily doped P-type region on the surface of the N+ region; through effective layout technology, it can reduce the dark count caused by the defect in the STI Dark counting; through effective guard ring technology, edge breakdown of SPAD devices can be prevented; by adding a suitable bias voltage between electrodes, its response in the blue light band can be enhanced.

The invention relates to a quenching and reading circuit for a single photon avalanche diode. The circuit comprises two achieving forms which both comprise the single photon avalanche diode and three NMOS (N-Mental-Oxide-Semiconductor) tubes. According to the a first embodiment, the quenching and reading circuit for the single photon avalanche diode comprises a first single photon avalanche diode, a first NMOS tube, a second NMOS tube and a third NMOS tube; a negative electrode of the first single photon avalanche diode is connected with a positive high pressure bias power source; a positive electrode of the first single photon avalanche diode is connected with a grid electrode of the first NMOS tube and a drain electrode of the second NMOS tube; a source electrode of the first NMOS tube and a source electrode of the second NMOS tube are connected with the ground; a grid electrode of the second NMOS tube is connected with a pulse signal; a source electrode of the third NMOS tube is connected with a drain electrode of the first NMOS tube; a grid electrode of the third NMOS tube is connected with a decoded signal; a drain electrode of the third NMOS tube is connected with a digit line. The quenching and reading circuit for the single photon avalanche diode has the advantages of being simple in structure, beneficial to system integration, rapid in response speed, high in detection accuracy, flexible and adjustable, stable and reliable and the like.

The invention provides a superconductive nanowire single-photon detector capable of distinguishing photon number. The superconductive nanowire single-photon detector consists of N superconductive nanowires which are connected in series and corresponding N bypass resistors, wherein each bypass resistor is arranged between every two adjacent superconductive nanowires; the superconductive nanowires are made from superconductive materials such as niobium nitride or titanium niobium nitride and the like; and the bypass resistors are made from metal films such as gold or titanium and the like. The invention further provides a method for preparing the superconductive nanowire single-photon detector. The prepared superconductive nanowire single-proton detector has high quantum efficiency, high counting efficiency, low dark count and capability of distinguishing photon number, and is not influenced by leakage current.

The invention provides a single-photon avalanche photodetector and a preparation method thereof, and the single-photon avalanche photodetector comprises a substrate; a multiplication layer which covers the substrate, wherein a charge layer is formed on the multiplication layer; a first silicon dioxide layer which covers the charge layer and part of the multiplication layer, wherein an epitaxial window is formed in the first silicon dioxide layer; a light absorption layer which is arranged in the epitaxial window, wherein a doping layer is formed on the light absorption layer; a second silicon dioxide layer which covers the surfaces of the doping layer, part of the light absorption layer and the first silicon dioxide layer, wherein an electrode window is formed in the second silicon dioxide layer, and part of the doping layer is exposed; an electrode which comprises a p electrode and an n electrode, wherein the p electrode is arranged in the electrode window, and the n electrode is arranged on the back surface of the substrate; and an anti-reflection layer which covers the second silicon dioxide layer, the p electrode and the doping layer, wherein the width of the charge layer is larger than that of the doped layer.

The invention provides a micro-nano optical fiber-waveguide-superconducting nanowire single-photon detector and a preparation method thereof. A micro-nano optical fiber fixed in a V-shaped groove can realize high-precision optical coupling alignment with a waveguide, and the transition section, which becomes thin from thick, of the micro-nano optical fiber is suspended, so that light is prevented from leaking to a substrate, and the loss in the optical transmission process is further reduced; the waveguide type superconducting nanowire structure can completely absorb light on a chip; due to the design of the corner waveguide, an optical coupling area of the micro-nano optical fiber-waveguide can be completely separated from an optical detection area of the waveguide type superconducting nanowire structure, dark counting caused by background radiation propagating along the optical fiber can be effectively reduced, and the influence of the background dark counting on optical detection is reduced; according to the invention, a single-photon detector integrating high detection efficiency, high counting rate, low time jitter and low dark counting can be realized, and the detector is expected to play a role in the fields of light quantum information processing, quantum optics and the like.

The invention provides a high-efficiency single-photon detection system and method applied to an area array up-conversion camera. The system at least comprises a core processing module, an active quenching module, a rapid recovery module, an adjustable high-voltage module, an adjustable medium-voltage module, a counting signal processing module and a protection module. The core processing module is configured to enable the avalanche diode to work in a Geiger mode through the adjustable high-voltage module, acquire an avalanche signal of a cathode of the avalanche diode through the counting signal processing module, and perform active quenching control of the avalanche diode through the active quenching module and the adjustable medium-voltage module. The avalanche diode is quickly recovered to Geiger mode control through the quick recovery module; the protection module is configured to control the connection between the active quenching circuit and the avalanche diode according to a voltage signal generated by the avalanche signal on the sampling resistor; the dark counting is reduced, the detection efficiency is improved, and the saturation counting rate is improved.

The invention discloses an integrated low-delay active quenching near-infrared single-photon detector, which comprises an active quenching circuit and an active recovery circuit, the active quenchingcircuit comprises an APD chip, a reverse amplifier, a high-speed comparator and an identification level adjusting circuit, the anode of the APD chip is connected to the forward input end of the high-speed comparator through a balance capacitor Cc, and meanwhile the anode of the APD chip is connected to the direct-current bias control circuit; the cathode of the APD chip is divided into two paths,one path is connected to the reverse input end of the high-speed comparator and the identification level adjustment circuit through the balance resistor R and the balance capacitor Cd1, and the otherpath is connected with the quenching transistor bias circuit; the forward output end of the high-speed comparator is connected with the reverse amplifier to generate a quenching signal and send the quenching signal to the cathode of the APD chip; the active recovery circuit controls a pulse trigger for the FPGA, and the pulse trigger is connected with the forward enabling end of the high-speed comparator. The detector has the advantages that the USB power supply circuit can be directly powered by a USB, and has low post-pulse probability and strong practicability in the case of low dead time and high detection efficiency.

A biological flow type analyzer relates to an analyzer, in particular to a biological flow type analyzer and application thereof. The present invention provides a biological flow type analyzer high insensitivity, comprising an optical system, a liquid flow system and a detection system, wherein the optical system is provided with an optical platform, a solid-state laser, a translation table, a continuous-adjustable attenuator, a reflecting mirror, an achromatic scuffing lens, a quartz circulating pool, a first aspheric lens, a second aspheric lens, a third aspheric lens, a first optical filter, a second optical filter and a third optical filter; the liquid flow system is provided with a nitrogen cylinder, a triple valve, a first switch valve, a second switch valve, a third switch valve, afourth switch valve, a pressure regulator, a pressure sensor, a four-way valve, an injector, a quartz capillary tube, a sample tube, a sample injector, a sheath liquid bottle and a waste liquid bottle; the detection system is provided with a first detector, a second detector, a translation table, a data acquisition card and signal acquisition software.

The invention relates to the field of fiber bragg grating signal demodulation, and in particular, relates to a high-precision fiber bragg grating signal demodulation system which comprises a pulse driving source, a laser, a circulator, a fiber bragg grating sensor, an adjustable attenuator, a single-photon detector, a time-to-digital converter and an information processor. The fiber bragg gratingsignal demodulation method comprises the following steps that: step 1, a laser device emits lasers with different wavelengths, and the lasers reach the fiber bragg grating sensor through the circulator and are reflected to the single-photon detector; step 2, the time-to-digital converter measures a single-photon counting value reaching the single-photon detector; step 3, the information processorobtains a measurement signal according to the single photon counting value measured by the time-to-digital converter, and the measurement signal change amount of the two reflected pulse light reachingthe single photon detector can be obtained according to the measurement signal; and step 4, the drift amount of the reflection center wavelength of the fiber bragg grating is demodulated according tothe change amount of the measurement signal. The problem that in an existing detection mode, the physical quantity of the fiber grating sensor cannot be accurately measured is solved.

The invention discloses an integrated gating active quenching / restoring circuit. The integrated gating active quenching / restoring circuit comprises a quick detection circuit, a pulse generation circuit, a pixel control circuit, a quenching circuit and a restoring circuit, wherein the quick detection circuit is used for processing a detected anode current signal of an SPAD (Single Photon Avalanche Diode) into a pulse signal, the pulse signal can be output through the pulse generation circuit, the pixel control circuit is controlled by an output signal and a gating signal of the pulse generation circuit, the restoring circuit and the quenching circuit are respectively controlled by outputs of the pixel generation circuit, outputs of the restoring circuit and the quenching circuit can be fed back to an anode of the SPAD, and the restoring and the quenching of the SPAD can be controlled. According to the integrated gating active quenching / restoring circuit disclosed by the invention, by adopting a gating control method, the dark counting rate of the SPAD can be effectively reduced, the quenching time can be controlled by the pulse generation circuit, and the integrated gating active quenching / restoring circuit has the advantages of compact area and low power consumption.

The invention relates to the field of photoelectric detection, in particular to a gated silicon-based visible near-infrared single-photon detection device which comprises a direct-current high-voltage power supply, a radio-frequency transformer, a high-speed CMOS driver, an FPGA, a high-speed comparator, a human-computer interaction interface and a silicon-based visible near-infrared single-photon detector SAPD. The direct-current high-voltage power supply is connected in series with the inductor and the current-limiting resistor and then is connected with an N pole of the silicon-based visible near-infrared single-photon detector SAPD. The high-voltage gating pulse with short rising and falling time can be generated, the dark counting and post-pulse probability can be effectively reduced while the single-photon detection efficiency is improved, peak noise caused by the front edge and the rear edge of the gating pulse can be effectively filtered out, counting of avalanche signals is achieved, meanwhile, the width, the amplitude and the repetition frequency of the gating pulse can be adjusted, and working points can be conveniently adjusted for different silicon-based visible near-infrared single-photon detectors, so that the performance is better.

The invention discloses a single-photon avalanche diode detector array unit with high detection efficiency. The array unit is a SPAD structure with surrounding P-injection, P-buried layer and deep P-well protected by P-buried layer. A deep P well is formed by ion implantation in the deep P well. There are two buried layer regions in the deep P well, namely the P buried layer region 3 and the P-buried layer region 4. There is a P-implanted region above the P-buried layer region 4. 8 surround. The array unit structure can effectively improve the photon detection efficiency of the SPAD device, and the dark count rate is very low, which greatly improves the overall performance of the SPAD detector.

The present invention relates to a superconducting nanowire single photon detector comprising a superconducting nanowire configured and arranged for incidence of photons on a region of the superconducting nanowire and for forming a local non-superconducting region or hot spot on the region. The superconducting nanowire is made of a high Tc cuprate superconductor material having a superconducting critical temperature above 77K. The invention also relates to a method of obtaining a superconducting nanowire single photon detector of the invention.

The invention discloses an integrated low-delay active quenching near-infrared single-photon detector, which comprises an active quenching circuit and an active recovery circuit, the active quenchingcircuit comprises an APD chip, a reverse amplifier, a high-speed comparator and an identification level adjusting circuit, the anode of the APD chip is connected to the forward input end of the high-speed comparator through a balance capacitor Cc, and meanwhile the anode of the APD chip is connected to the direct-current bias control circuit; the cathode of the APD chip is divided into two paths,one path is connected to the reverse input end of the high-speed comparator and the identification level adjustment circuit through the balance resistor R and the balance capacitor Cd1, and the otherpath is connected with the quenching transistor bias circuit; the forward output end of the high-speed comparator is connected with the reverse amplifier to generate a quenching signal and send the quenching signal to the cathode of the APD chip; the active recovery circuit controls a pulse trigger for the FPGA, and the pulse trigger is connected with the forward enabling end of the high-speed comparator. The detector has the advantages that the USB power supply circuit can be directly powered by a USB, and has low post-pulse probability and strong practicability in the case of low dead time and high detection efficiency.

The invention relates to a fully-integrated high-speed single photon detecting system, comprising a precision clock source V1, wherein an output end of the precision clock source V1 is connected with an input end of an input filtering and amplifying module; an output end of the input filtering and amplifying module is connected with a temperature control module; an avalanche photodiode (APD) and a low noise direct current bias supply P1 are packaged in the temperature control module which is connected with an input end of an output filtering and amplifying module by a directional coupler; andan output end of the output filtering and amplifying module is connected with a counting module by a screening coincidence and dead time setting module. The invention also discloses a detecting method of the fully-integrated high-speed single photon detecting system. The fully-integrated high-speed single photon detecting system can strictly inhibit a back pulse effect, has a working frequency of 2 GHz and a counting rate of 100 MHz, is especially suitable for a quantum cryptographic system.