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492 results about "Photon detector" patented technology

Single-photon avalanche diode and single-photon detector

The invention provides a single-photon avalanche diode and a single-photon detector, and relates to the technical field of semiconductor photoelectric detection, and the single-photon avalanche diode comprises a plurality of avalanche diode units. The avalanche diode units are sequentially stacked in the propagation direction of incident light to be detected. Each avalanche diode unit is provided with an electric field control module which is used for independently adjusting the bias electric field of each avalanche diode unit. In the propagation direction of the incident light, the avalanche diode unit of the next stage is used for absorbing the remaining photons which are not absorbed by the avalanche diode unit of the previous stage and generating carriers, so that avalanche current is formed. The light absorption wavelength ranges of adjacent avalanche diode units are at least partially overlapped. The single-photon avalanche diode solves the problem that the existing single-photon avalanche diode cannot balance high detection efficiency and low dark current, and achieves the purpose of improving the detection efficiency of a single-photon detector on the premise of not increasing the dark current.
Owner:MOZI LABORATORY

Optical time domain reflectometer and control method of optical time domain reflectometer

The invention relates to an optical time domain reflectometer and a control method of the optical time domain reflectometer, and relates to the technical field of photoelectricity. The optical time domain reflectometer OTDR comprises a single photon detector, and the OTDR is used for being connected with an optical fiber to be measured; the OTDR is further used for sending a plurality of detection signals to the optical fiber to be detected in sequence and receiving a plurality of detection echo signals from the optical fiber to be detected in sequence, and the detection echo signals are used for indicating the transmission state of the same section of transmission area in the optical fiber to be detected; performing amplitude reduction processing on each detection echo signal at a certain time interval to obtain a processed detection echo signal; the positions, corresponding to the same section of transmission area, of the signal sections subjected to amplitude reduction processing in the different processed detection echo signals are not completely the same; each processed detection echo signal is subjected to photoelectric conversion based on the single-photon detector to obtain a first electric signal, a first OTDR oscillogram is output based on the multiple first electric signals, and the first OTDR oscillogram is used for indicating the transmission state of the same section of transmission area. Therefore, the problem of OTDR curve distortion can be solved.
Owner:HUAWEI TECH CO LTD

Computational imaging method of cross strip-shaped anode single-photon detector

The invention relates to the field of computational imaging, in particular to a computational imaging method of a crossed strip-shaped anode single-photon detector, which comprises the following steps of: screening effective data through full-view-field illumination, and calculating an average output signal amplitude of each anode strip and a total average output signal amplitude of all anode strips to obtain a correction factor; the method comprises the following steps of: correcting an original output signal of each anode strip by adopting a correction factor during target imaging, performing effective signal data screening on the corrected original output signal, substituting effective signal data into a Gaussian algorithm to calculate an incidence position coordinate, mapping the incidence position coordinate to a mapping matrix, and stretching the incidence position coordinate to a 256 gray level for display. According to the calculation imaging method provided by the invention, the fixed mode noise can be suppressed, the imaging resolution is improved, and the image distortion is reduced.
Owner:CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI

LED display screen defect rapid detection method

The invention relates to the field of LED display screen defect detection, in particular to an LED display screen defect rapid detection method. The method specifically comprises the steps that polarization entangled photon pairs are generated through a first detection assembly, the photon pair coincidence counting rate is measured through an HOM interferometer and a single-photon detector in a second detection assembly, and a photon pair anomaly distribution diagram is generated; establishing a correlation model of the photon pair coincidence counting rate and the electronic state density, and analyzing internal defects of the display screen; an integrated high-speed CMOS camera and a multiband LED annular light source are adopted to collect four-channel image data, and features are extracted to generate an image data abnormal probability graph; and finally, integrating a quantum optical measurement result and an image analysis result through coordinate mapping, judging a final defect area and type based on a decision tree rule, and covering various defect types such as material internal defects, surface reflection abnormity and color unevenness. According to the method, the efficiency and the accuracy of LED display screen defect detection are remarkably improved.
Owner:SHENZHEN BRIGHTER LED TECH CO LTD

Ai-driven motion correction of pet data

Systems and methods include acquisition of an anatomical image of an object, acquisition of molecular imaging data of the object at the plurality of photon detectors, reconstruction of a functional image based on the molecular imaging data, input of the anatomical image and the functional image to a trained neural network to generate a second functional image, and presentation of the second functional image.
Owner:SIEMENS MEDICAL SOLUTIONS USA INC

Single-photon non-vision-field target tracking system based on unmanned aerial vehicle platform

The invention discloses a single-photon non-vision-field target tracking system based on an unmanned aerial vehicle platform, which belongs to the field of non-vision-field imaging and is characterized in that a laser is connected with a scanning galvanometer assembly through a first nanosecond optical path switch and an optical fiber circulator to form an emission optical path for emitting laser pulses to relay reflecting surfaces corresponding to four predetermined positioning points; the scanning galvanometer assembly is connected with the photon detector through the collimating optical fiber, the optical fiber circulator and the second nanosecond optical path switch to form a receiving optical path capable of receiving echo photons; the main control module is electrically connected with the laser, the first nanosecond light path switch, the second nanosecond light path switch, the scanning galvanometer assembly, the photon detector, the time-to-digital converter and the high-frequency inertial measurement unit respectively, and can control each component to perform laser ranging, double-window gating, single-photon detection, inertial measurement unit sampling and timing according to a unified time sequence; and the three-dimensional coordinates of the current non-vision target are calculated by using the distance measurement data through an ellipsoid intersection solution method, so that non-vision target tracking is realized.
Owner:UNIV OF SCI & TECH OF CHINA

Multifunctional standard single photon source generation and calibration device and use method

The invention relates to the technical field of light quantum metering, in particular to a multifunctional standard single photon source generation and calibration device and a use method, and the device comprises a pumping laser light source, a nonlinear crystal, a signal optical filter, a beam splitter, a temperature control module, an idler frequency optical filter, a control module, a single photon detector group, a beam splitter, a multi-channel coincidence counter, and an optical switch. The pumping laser light source pumps the nonlinear crystal to generate two paths of single photon output of signal light and idler frequency light, the two paths of single photon output are filtered by the filter and then divided into multiple paths by the beam splitter, and standard single photons are directly output or the paths of the signal light or the idler frequency light are controlled by the optical switch to enter the single photon detector group for detection. External input single photons are controlled by the optical switch to enter the single-photon detector group for detection, and a count value of the single-photon detector group is accessed to the multichannel coincidence counter to record data. A pump light stable power system and a multi-path beam splitting coincidence counting system are introduced into a light path, so that standard single photon output with known brightness and g (2) (0) value can be realized.
Owner:THE 41ST INST OF CHINA ELECTRONICS TECH GRP

Distance measurement communication fusion miniaturization system and method based on single photon detection

The invention discloses a ranging communication fusion miniaturized system and method based on single photon detection. The system adopts a time division multiplexing common-path structure, and a ranging pulse sequence and a communication pulse sequence are sequentially transmitted in the same detection period to form a PPM modulation laser pulse chain. A single-photon detector is adopted to receive signals, background light interference is suppressed by combining a narrow-band filter and a time gating technology, and the type and boundary of a pulse sequence are identified through a signal demodulation and discrimination module. When the distance measurement pulse sequence is identified, the distance measurement path realizes distance measurement based on the round-trip time of the distance measurement pulse in the period; when a communication pulse sequence is identified, the communication path demodulates the PPM communication data. The method effectively decouples the contradiction between the distance measurement fuzzy and the communication rate, supports communication pulse high repetition frequency modulation while realizing non-fuzzy distance measurement, improves the distance measurement precision and the communication rate, and is suitable for free space communication, mobile robot platforms and other application scenes.
Owner:INST OF OPTICS & ELECTRONICS CHINESE ACAD OF SCI +1

Slope displacement monitoring method and device based on quantum single photon and medium

The invention discloses a side slope displacement monitoring method and device based on quantum single photons and a medium, and belongs to the technical field of displacement monitoring. Rectangular light pulses are emitted periodically, echo detection is completed by using a single photon detector, a photon counting time sequence is constructed, wavelet denoising and reconstruction processing is performed on the photon counting time sequence, main peak position offset, energy change and form distortion are extracted to match multiple types of feature vectors, and feature fusion and resolving are performed through a multi-source feature fusion BP neural network. And finally outputting a high-precision slope displacement result. According to the method, the quantum single-photon detection technology is combined with the wavelet denoising and neural network fusion algorithm, noise interference is effectively suppressed, the displacement feature extraction precision is improved, and the method is suitable for high-precision and long-distance slope micro-deformation real-time monitoring.
Owner:SICHUAN LIANGSHANSHUILUOHE ELECTRICITY DEV CO LTD

Single-photon laser multispectral polarization detection method and system under underwater turbulence disturbance

According to the single-photon laser multispectral polarization detection method and system under underwater turbulence disturbance provided by the invention, pulse laser is emitted to a target after being scanned, and weak echoes of the pulse laser are received by a double-photon detector and a single-photon detector after being subjected to spectral filtering and spatial polarization beam splitting. A time correlation single photon counting technology is adopted, time, polarization and wavelength information of each photon is recorded synchronously, and a multi-dimensional data set is generated in combination with a scanning angle. After turbulence noise is suppressed through preprocessing, target distance information is extracted to generate a three-dimensional point cloud, and the polarization degree and the depolarization ratio of each pixel point are calculated; and finally, geometric, polarization and spectral data are fused, a high-precision three-dimensional terrain and polarization image is generated, and accurate target identification in a complex underwater environment is realized. According to the invention, a set of multi-dimensional information sensing system capable of carrying out long-distance, high-resolution and high-precision classification and identification on a target in a complex underwater environment with strong attenuation, strong noise and strong turbulence disturbance is constructed.
Owner:HANGZHOU INST FOR ADVANCED STUDY UCAS

Zero dead time single photon counting system based on time division multiplexing

The invention discloses a zero-dead-time single photon counting system based on time division multiplexing, and belongs to the technical field of laser radars. The system comprises an optical multiplexer, N detection channels, N delay modules, a shift register and a counting circuit, according to a time division multiplexing mechanism, a time axis is divided into a plurality of independent time slots, and in different time slots, incident signal light is input into different detection channels according to a preset sequence, so that zero-dead-time single photon counting is realized. According to the invention, the dead time problem of a traditional single-photon detector is solved, the photon counting pulse and the dark current pulse are effectively distinguished through a multi-parameter pulse discrimination technology, the signal-to-noise ratio of the system is significantly improved, and a reliable solution is provided for application scenes requiring high-sensitivity detection, such as laser radar and quantum communication.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Improvements in and relating to photonics

Improvements in and relating to Photonics An optical switch for receiving an optical signal from an optical signal source and for outputting the optical signal comprises an optical router configured for routing the optical signal conditional on the detection of a single photon. The optical router comprises and optical resonator, a first optical pathway part comprising the optical resonator, and a second optical pathway part. An optical input coupling part receives the optical signal for coupling the received optical signal into the first optical pathway part and into the second optical pathway part. An optical modulator coupled to a single-photon detector unit outputs a detection signal in response to the detection of a single photon. The optical modulator is configured, in response to the detection signal, to modulate the refractive index of the optical resonator to change an optical phase shift incurred by the optical signal upon passage through the optical resonator such that an optical interference results in a routing of the output optical signal to one of the first and second optical pathway parts selected conditional on the detection of a single photon.
Owner:DUALITY QUANTUM PHOTONICS LTD

Single-photon detector performance parameter measurement method, device and equipment and storage medium

The invention relates to the technical field of single-photon detection, in particular to a single-photon detector performance parameter measurement method, device and equipment and a storage medium, and the method comprises the steps: building a statistical histogram of time domain interval data, and building the statistical distribution characteristics of the photon counting rate and dark counting of a single-photon detector; the probability of no photon detection event in the duration of the optical pulse and the ideal probability of no dark pulse in a preset time window are defined based on the statistical distribution characteristics, and then the probability of generating a single photon signal by the periodic optical pulse is calculated based on the obtained parameters; and finally, determining a periodic statistical peak count value based on the statistical histogram and the probability of generating the single photon signal by the periodic light pulse, and calculating an average detection photon number and a dark count rate so as to obtain the dead zone time, so that information such as the average detection photon number, the dark count rate and the dead zone time of the single photon detector is simultaneously represented through one-time data acquisition, and the detection accuracy of the single photon detector is improved. The problems that in a traditional method, the data storage amount is large, and cost is high are solved.
Owner:JIHUA LAB

Method for representing detection efficiency of sine-gated single-photon detector by using continuous light

The invention discloses a method for representing the detection efficiency of a sine-gated single-photon detector by using continuous light. The method comprises the following steps: collecting count values of the single-photon detector under different bias voltages; calculating an initial gate width, an initial average photon number and initial detection efficiency according to the initial over-bias voltage; increasing the bias voltage by a step value, calculating widths of different parts of gate pulse detection efficiency under the voltage, and calculating count values of the different parts; subtracting the count value measured under the bias voltage from the sum of the count values of all the parts to obtain a corrected count value, and calculating the detection efficiency; whether the bias voltage reaches a set maximum value or not is judged, if not, the bias voltage continues to be increased, and meanwhile the detection efficiency is corrected; and if the maximum value is reached, the detection efficiency obtained through processing is used as a final calibration value. The method can correct the detection efficiency when a continuous light source is used, and eliminates the influence of a plurality of voltage intervals, so as to calibrate the maximum detection efficiency of the detector.
Owner:SOUTH CHINA NORMAL UNIV

Silicon carbide single-photon detector and preparation method thereof

PendingCN121310668ACarbide siliconResponsivity
The invention provides a silicon carbide single-photon detector and a preparation method thereof, and relates to the technical field of silicon carbide solar blind detection. The silicon carbide multiplication layer and the aluminum gallium nitrogen absorption layer of different material systems are sequentially grown on the silicon carbide substrate, and the side, far away from the silicon carbide substrate, of the aluminum gallium nitrogen absorption layer is the light incidence side, so that incident light firstly passes through the aluminum gallium nitrogen absorption layer and is excited to generate current carriers, and then the current carriers are multiplied by the multiplication layer to generate internal gain, so that the light emitting efficiency is improved. The detection sensitivity is improved. The forbidden bandwidth range of the aluminum gallium nitrogen absorption layer coincides with the photon energy range of the solar-blind wave band, so that the aluminum gallium nitrogen absorption layer only absorbs the solar-blind wave band and transmits the wave band outside the solar-blind wave band, absorption of photons outside the solar-blind wave band when a silicon carbide absorption layer is adopted is avoided, light filtering in a light filter mode is also avoided, and the detection responsivity is improved.
Owner:THE 13TH RES INST OF CHINA ELECTRONICS TECH GRP CORP

Teleportation systems toward a quantum internet

Quantum teleportation is essential for many quantum information technologies, including long-distance quantum networks. Using fiber-coupled devices, including state-of-the-art low-noise superconducting nanowire single-photon detectors and off-the-shelf optics, we achieve conditional quantum teleportation of time-bin qubits at the telecommunication wavelength of 1536.5 nm. We measure teleportation fidelities of ≥90% that are consistent with an analytical model of our system, which includes realistic imperfections. To demonstrate the compatibility of our setup with deployed quantum networks, we teleport qubits over 22 km of single-mode fiber while transmitting qubits over an additional 22 km of fiber. Our systems, which are compatible with emerging solid-state quantum devices, provide a realistic foundation for a high-fidelity quantum Internet with practical devices.
Owner:CALIFORNIA INST OF TECH

Cross strip-shaped anode single-photon detector imaging method based on deep learning

The invention relates to the technical field of photon detection imaging, in particular to a deep learning-based crossed strip-shaped anode single-photon detector imaging method, which comprises the following steps of: enabling incident photons to enter a crossed strip-shaped anode single-photon detector to obtain charge signals on a crossed strip-shaped anode in the detector; sampling the charge signal; inputting the obtained sampling data into a trained decoding network model to obtain a predicted position of an incident photon; establishing an imaging matrix, mapping the obtained prediction position into the imaging matrix, and performing interval division on the mapped imaging matrix; and carrying out gray value mapping on the number of photons in the divided intervals to obtain an imaging result. According to the invention, the neural network model is introduced to carry out computational imaging, so that the imaging quality of the cross strip-shaped anode single-photon detector is improved.
Owner:CHANGCHUN INST OF OPTICS FINE MECHANICS & PHYSICS CHINESE ACAD OF SCI

Quantum key distribution system based on PZT phase modulation and PZT phase correction method

The invention discloses a quantum key distribution system based on PZT phase modulation and a PZT phase correction method. The method specifically comprises the following steps: determining expected working voltages of a first PZT and a second PZT; dynamically adjusting the working voltage of the first PZT based on the current detection error rate of the first zero-beat single-photon detector SPD or the second zero-beat single-photon detector SPD and the deviation distance between the current working voltage of the first PZT and the expected working voltage; and dynamically adjusting the working voltage of the second PZT based on the detection error rate of the third zero-beat single-photon detector SPD or the fourth zero-beat single-photon detector SPD and the deviation distance between the current working voltage and the expected working voltage of the second PZT. The PZT is used as the phase modulator, phase modulation is performed on light quantum, passive decoding is performed according to the response of the detector, the phase modulator does not need to participate in modulation, high-speed quantum random number resources of 2bit / photon are reduced, and the practical application cost and difficulty of the high-speed quantum key distribution system are greatly reduced.
Owner:ANHUI QASKY QUANTUM SCI & TECH CO LTD

Quantum random number generation device, chip and quantum random number generation method

The invention discloses a quantum random number generation device, a chip and a quantum random number generation method, and belongs to the technical field of random number generation. The device comprises: a light source for emitting a photon stream to an optical waveguide; the optical waveguide is used for attenuating the number of photons of the photon flow and outputting the photons to the photon detector; the photon detector is used for receiving the photons output by the optical waveguide, generating pulse signals based on the arrival time of the photons and sending the pulse signals to the data processing equipment; and the data processing equipment is used for generating the quantum random number according to the pulse signal. By utilizing the optical characteristics of the optical waveguide, the number of photons reaching the photon detector after the photon flow passes through the optical waveguide is reduced, compared with the mode of attenuating the number of photons through a free space optical path and optical element combination, the size of the optical waveguide is smaller, and the optical waveguide is more suitable for being integrated with a silicon chip; therefore, the occupied space of the quantum entropy source can be reduced, and the miniaturization and chip development of the quantum random number generator is promoted.
Owner:BEIJING SMARTCHIP MICROELECTRONICS TECHNOLOGY CO LTD +1

Linear optical qubit amplifier under time mode coding

PendingCN120686484ANon-linear opticsBeam splitterQuantum amplifier
The invention provides a linear optical quantum amplifier based on coding in time modes, which comprises a first photon detector and a second photon detector in two time modes, and an input end beam splitter, a first beam splitter, a second beam splitter and an output end beam splitter, the first photon detector is used for detecting photons appearing in a first time window of the upper path, and the second photon detector is used for detecting photons appearing in a second time window of the lower path; the input end beam splitter and the output end beam splitter completely transmit photons emitted in a first time window and completely reflect photons emitted in a second time window at the same time, the first beam splitter completely reflects the photons emitted in the first time window and reflects the photons emitted in the second time window with the reflectivity of gamma, and the second beam splitter completely reflects the photons emitted in the second time window with the reflectivity of gamma. And the first beam splitter completely reflects the incident photons in the first time window and transmits the incident photons in the second time window by a transmission coefficient of 1-gamma, the second beam splitter completely reflects the incident photons in the second time window and reflects the incident photons in the first window by a reflectivity of gamma, and the first beam splitter transmits the incident photons in the first time window by a transmission coefficient of 1-gamma. The method is more concise, easy to operate and better in amplification effect, and a large number of sub-state amplification protocols are achieved.
Owner:NANJING UNIV OF SCI & TECH

System and method for generating gating signal of single-photon detector

The invention provides a single-photon detector gating signal generation system and generation method. The system comprises a bias voltage source; the gating circuit is provided with a first sine branch and a second sine branch, the first sine branch is configured to output a first sine voltage signal, and the second sine branch is configured to output a second sine voltage signal; the frequency of the first sinusoidal voltage signal is greater than that of the second sinusoidal voltage signal; the second sinusoidal voltage signal, the first sinusoidal voltage signal and the bias voltage signal are matched to generate a gating signal acting on the avalanche photodiode; based on the period of the first sinusoidal voltage signal, the gating signal has an amplitude greater than a preset value in a continuous first number of periods, and the gating signal does not have an amplitude greater than the preset value in a subsequent continuous second number of periods. The generated gating signal can accelerate the carrier removal process from the physical mechanism level, the post-pulse probability is suppressed, the required dead time is effectively shortened, and the data rate of the detector is further improved.
Owner:MOZI LABORATORY

YBCO (Yttrium Barium Copper Oxide) film for single-photon detector and deposition method of YBCO film

The invention provides a YBCO (Yttrium Barium Copper Oxide) film for a single-photon detector and a deposition method thereof, and the deposition method comprises the following steps: S1, fixing a substrate on a substrate table of pulse laser deposition equipment, vacuumizing, and heating the substrate table to a deposition temperature; s2, oxygen is introduced into the deposition cavity until the oxygen pressure ranges from 0.25 Torr to 0.35 Torr; s3, adopting a YBCO target material, and carrying out pre-sputtering in a baffle closing state; s4, a baffle is opened, sputtering is conducted on the YBCO target material, and a YBCO film precursor is obtained; s5, oxygen is introduced into the deposition cavity, and meanwhile, the annealing temperature is reduced for in-situ annealing treatment; and S6, cooling to room temperature to obtain the YBCO film. According to the method, the high-quality ultrathin YBCO film with the thickness as low as 14 nm is prepared by accurately controlling the deposition parameters and the annealing process of the oxygen atmosphere, the prepared YBCO film still keeps excellent superconducting performance under the ultrathin condition, and the refrigeration cost is greatly reduced.
Owner:SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI

Teleportation systems toward a quantum internet

Quantum teleportation is essential for many quantum information technologies, including long-distance quantum networks. Using fiber-coupled devices, including state-of-the-art low-noise superconducting nanowire single-photon detectors and off-the-shelf optics, we achieve conditional quantum teleportation of time-bin qubits at the telecommunication wavelength of 1536.5 nm. We measure teleportation fidelities of ≥9% that are consistent with an analytical model of our system, which includes realistic imperfections. To demonstrate the compatibility of our setup with deployed quantum networks, we teleport qubits over 22 km of single-mode fiber while transmitting qubits over an additional 22 km of fiber. Our systems, which are compatible with emerging solid-state quantum devices, provide a realistic foundation for a high-fidelity quantum Internet with practical devices.
Owner:CALIFORNIA INST OF TECH

Quantum navigation positioning device and method

A quantum navigation and positioning device and method belongs to the field of data processing technology, and includes: a controller that receives and pre-processes photon information of entangled photon pairs; and a controller that executes a quantum navigation and positioning algorithm. The controller applies a Kalman filter algorithm to the data collected by the photon detector to perform denoising processing, thereby improving the quality and availability of the data collected by the photon detector and preparing for subsequent quantum navigation and positioning calculations. The photon detector operates in a low-temperature environment, and the temperature range of the low-temperature environment is 2K to 3K. The use of a low-temperature environment can reduce the noise of the photon detector and provide a guarantee for obtaining high-quality photon measurement data. This effectively avoids the defects of the prior art in that the photon detectors used for quantum navigation and positioning are often interfered with by noise, resulting in poor detection performance, and the photon detectors are also interfered with by noise during the transmission of their collected data to the controller for quantum navigation and positioning, which is not conducive to the effect of quantum navigation and positioning.
Owner:BEIJING DINGCHENG HONGAN TECH DEV CO LTD +1

System for implementing quantum key distribution (QKD) in a data center environment

Systems and methods are described for implementing quantum key distribution (QKD) in a data center environment. An example quantum transmitter includes an on-chip semiconductor laser as a light source to generate photons, quantum state preparation circuitry configured to receive a sequence of bits, map each bit to a quantum state and a measurement basis, and encode the quantum state of each bit onto a corresponding photon to generate a qubit, and a quantum channel interface configured to transmit the qubit to a quantum receiver via a quantum communication channel. An example quantum receiver includes a quantum channel interface to receive qubits, a silicon-based single photon avalanche diode (SPAD) as a photon detector for qubit detection, and quantum state measurement circuitry that is configured to decode the state of each qubit based on a selected measurement basis.
Owner:MELLANOX TECHNOLOGIES LTD(IL)

Preparation method and equipment of entangled light source based on grating and perfect vortex metasurface

The invention relates to a preparation method of an entangled light source based on a grating and a perfect vortex metasurface, and the method comprises the steps: providing a Gaussian beam, carrying out the linear polarization of the Gaussian beam in a specific polarization direction, and generating signal light and idle light through a periodically poled potassium titanate crystal; after the photons are collimated, the polarization states of the signal light and the idle light are changed through a 1 / 4 wave plate, and the signal light and the idle light are respectively converted into right-handed circular polarization and left-handed circular polarization; the Gaussian beam passes through the perfect vortex metasurface to obtain a geometric phase changing along with space; through the one-dimensional grating, the left-handed perfect vortex light and the right-handed perfect vortex light are separated to output an overlapped part entangled state; and respectively coupling the photons in the two paths into an optical fiber, and transmitting the photons to a single-photon detector to record a coincidence number.
Owner:HUNAN UNIV

Blood oxygen-blood flow synchronous and same-position acquisition device and method for diffused light tissue imaging

The invention belongs to the technical field of biomedical engineering measurement, and discloses a diffused light tissue imaging blood oxygen-blood flow synchronous and same-position acquisition device which comprises a three-wavelength near-infrared laser, a plurality of multimode optical fibers, a first optical switch, a second optical switch, a plurality of Y-shaped optical fibers, a DOS / DOT photon detector module and a DCS / DCT photon detector module. The output end of the three-wavelength near-infrared laser is connected with one end of each multi-mode optical fiber through the first optical switch, and the other end of each multi-mode optical fiber is arranged on the surface of a measured medium; the common end of each Y-shaped optical fiber is arranged on the surface of a detected medium, a first branch port of each Y-shaped optical fiber is connected with the DOS / DOT photon detector module through the second optical switch, and a second branch port of each Y-shaped optical fiber is connected with the DCS / DCT photon detector module through the second optical switch. According to the invention, DOS / DOT and DCS / DCT are fused, simultaneous and same-position acquisition of tissue blood flow and blood oxygen signals is realized, the dimension of clinical information measured by a diffused light technology is widened, and the accuracy of oxygen metabolism rate calculation is improved.
Owner:ZHONGBEI UNIV

Thermoluminescence dating device using low-dose source irradiation

The invention relates to the technical field of thermoluminescence dating, and discloses a thermoluminescence dating device using low-dose source irradiation, comprising: a detection module adopting a multi-channel detection technology and having a built-in photon detector; the heating module is used for heating the sample to be detected, releasing energy stored in the sample and generating a thermoluminescence signal; the radiation module is used for irradiating the sample and simulating radiation conditions in a natural environment; the data acquisition and analysis module is responsible for recording the signal from the detection module and processing and analyzing the signal; and the mounting module is used for placing a sample to be tested. The thermoluminescence dating device provided by the invention is simple in structure and convenient for a user to load and sample, and can realize that the irradiation unit is close to the limit of the sample and increase the source dose rate, thereby realizing the purpose of low-dose source irradiation, simplifying the equipment management and approval procedures, and then more accurately compensating signal deviation caused by external factors, and improving the dating accuracy of the thermoluminescence dating device. And the measurement precision of the thermoluminescence dating device is improved.
Owner:HANGZHOU GLOW DETECTION TECHNOLOGY CO LTD

Post-pulse probability suppression method and system for single-photon detector

The invention discloses a single-photon detector post-pulse probability suppression method and system, and the method achieves the measurement of the arrival time of a detection pulse after a previous detection pulse, abandons the detection pulses in a certain time range, reduces the post-pulse probability, does not need to close a gate signal and hardware processing, and does not affect the performance of a detector. The post-pulse probability time distribution characteristics of the single-photon detector can be identified by means of a time periodic folding measurement scheme, so that the optimal suppression time window of the post-pulse probability of the single-photon detector can be reasonably adjusted according to the relationship between post-pulse probability distribution and the saturation counting rate, and the optimal detector performance is realized. The method has the characteristic of universality, is not only applied to a sine gating detector, but also can be applied to scenes such as a rectangular gating detector and a free operation detector which need to further suppress the post-pulse, and does not affect the original detection process.
Owner:QUANTUMCTEK CO LTD