368 results about "Photon detector" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The present invention relates to an improved system and method for imaging, based on single photon detectors (SPDs), whereby false positives are suppressed.

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.

The invention discloses a long-distance ranging and imaging integrated single-photon laser radar system and method, and belongs to the technical field of laser radars, a laser, a signal delayer and a single-photon detector are all connected with an upper computer, and the laser, the single-photon detector and the upper computer are all connected with the signal delayer; the laser is arranged outside the optical system and connected with a collimator, the single-photon detector is arranged on a focal plane of the optical system, a laser beam of the laser is parallel to an optical axis of the optical system, and a laser beam transmitting end of the laser faces a measured target; the surface of a photon chip of the single-photon detector is divided into a distance measuring area and an imaging area through coating, the distance measuring area is provided with a distance measuring reading circuit, the imaging area is provided with an imaging reading circuit, and the distance measuring reading circuit and the imaging reading circuit are respectively connected with the upper computer; the laser comprises a first laser and a second laser, the laser beam of the first laser returns to the ranging area, and the laser beam of the second laser returns to the imaging area.

The embodiment of the present application provides a laser communication modulation method and system thereof, which can solve the technical problem of poor sensitivity of free-space laser communication under extremely low signal-to-noise ratio conditions. The method includes performing polarization-selective modulation on a coding sequence to obtain multiple groups of linearly polarized light pulses. Each group of linearly polarized light pulses is sent to different photon detectors through different channels to obtain a first photon count and a second photon count. According to the first photon count and the second photon count of all groups of linearly polarized light pulses, a log-likelihood ratio is obtained through soft decision. Then, the original information prediction value is obtained through channel decoding. In this way, polarization-selective pulse position modulation and its corresponding demodulation method can obtain better communication sensitivity and stronger resistance to background noise compared to PPM‑PC. In addition, optical signals in different polarization states carry different data respectively, and are then transmitted in sequence, with a high transmission rate.

Embodiments of the present application provide a detector device including a photon detector and a multilayer reflector. The photon detector includes a substrate, an isolation structure in a first side of the substrate, a guard ring adjacent to the isolation structure and in the first side of the substrate, a sensor node in the first side of the substrate, the guard ring between the sensor node and the isolation structure, a shared node in the first side of the substrate, the shared node between the guard ring and the isolation structure, an isolation extension structure in a second side of the substrate opposite the first side, the isolation extension structure extending from the second side to the isolation structure. The multilayer reflector is on the first side of the substrate. Using the multilayer reflector can improve collection of photons in an avalanche region.

A method for improving negative correlation noise (anti-correlation noise) artifact reduction in spectral CT imaging includes detecting photon detector counts below a certain threshold (low count readings) and then determining a reliability indicator for each sinogram voxel with a set of detected low count readings. Those readings in the sinogram that are below threshold reliability are operated with smoothing operators. This is based on a pre-calculated probability distribution of different possible sets of probe count readings that is based on a theoretical probability of each combination of the read counts of a hypothetical attenuation distribution for a given scan volume.

This invention discloses a method for fabricating a highly sensitive long-wavelength infrared superconducting single-photon detector. It fully utilizes and amplifies the acoustic mismatch effect between the superconducting thin film and the substrate to achieve phonon localization enhancement on the superconducting nanowires. The effect of this innovative design is to increase the energy utilization rate of long-wavelength infrared photons on the superconducting nanowires, thereby improving the response sensitivity of the superconducting nanowires to long-wavelength infrared photon signals. Compared to existing designs that reduce the cross-sectional size of the superconducting nanowires, create holes beneath the nanowires, or increase the buffer layer, this invention is easier to implement and has higher scalability.

The application discloses an underwater wireless optical communication device based on a single photon detector, which comprises a first single photon communication device and a second single photon communication device for bidirectional communication, and each of the first single photon communication device and the second single photon communication device comprises a laser emission unit, a signal receiving unit, a signal comprehensive processing unit and a power module; the laser emission unit loads a received modulated electric signal into an optical signal and outputs the optical signal, and simultaneously emits auxiliary alignment laser for communication device alignment; the signal receiving unit converts the received optical signal into an electric signal through a single photon detector and transmits the electric signal to the outside, and simultaneously, the signal receiving unit receives auxiliary alignment laser to complete communication device alignment; the signal comprehensive processing unit converts communication information of a host computer into a modulated electric signal after receiving the communication information, transmits the modulated electric signal to the laser emission unit, demodulates and restores the electric signal transmitted by the signal receiving unit into communication information, and then transmits the communication information to the host computer. The application can improve underwater communication distance and meet the requirements of long-distance wireless optical communication in different water quality environments.

Array single photon detection and two-dimensional camera common path fusion device and pixel matching method belong to the field of optical precision measurement. The array single photon detection and two-dimensional camera common path fusion device comprises a signal generator, a laser, an emitting optical system, a receiving optical system, a dichroic mirror, a two-dimensional camera, an array single photon detector, an array single photon counter and a data acquisition and processing fusion module. The method of the present application is as follows: the array single photon detection waveband pulsed laser and the two-dimensional camera sensing waveband ambient light returned by the target object are separated by using a common receiving optical path and a dichroic mirror to determine the pixel size and the number of the array single photon detector and the two-dimensional camera; the transmission light offset d is calculated according to the thickness of the dichroic mirror; the transmission light offset d is used as a correction factor to realize the pixel matching of the array single photon detection three-dimensional imaging and the two-dimensional camera image; the array single photon detection three-dimensional image and the two-dimensional camera image are superimposed, and the high resolution of the two-dimensional image is used to enrich the three-dimensional point cloud imaging information.

The application relates to an avalanche diode single-photon detector and a preparation method thereof, in particular to a quantum dot-vertical linear avalanche diode single-photon detector and a preparation method thereof, and solves the problems of low detection efficiency of the existing single-photon detector and high preparation difficulty, high cost and limited effect of the existing method. + The detector comprises a detector N + substrate, a back electrode grown on the lower surface thereof, a plurality of quantum dot-vertical linear units arranged at intervals on the upper surface thereof, a passivation layer and a front electrode; the quantum dot-vertical linear unit comprises a semiconductor vertical linear structure, a porous nanomaterial layer and a quantum dot material layer; the semiconductor vertical linear structure is grown on the upper surface of the detector N + substrate; the porous nanomaterial layer covers the semiconductor vertical linear structure; the quantum dot material layer covers the porous nanomaterial layer; the passivation layer is filled between the quantum dot-vertical linear units; and the front electrode is grown on the part of the quantum dot-vertical linear unit extending out of the passivation layer.

This application provides an optical fiber sensing system, its calibration method, and a storage medium, relating to the field of optical fiber sensing technology, to improve the dynamic range of the optical fiber sensing system. The optical fiber sensing system includes a signal generator, an optical fiber circulator, a reference optical fiber, a single-photon detector, a processor, and a sensing optical fiber. The signal generator, reference optical fiber, and single-photon detector are respectively connected to the optical fiber circulator. The sensing optical fiber is connected to the reference optical fiber. The single-photon detector is used to acquire a first reference measurement signal and a second reference measurement signal. The first reference measurement signal has attenuation compared to the second reference measurement signal. The processor is used to determine a dead time based on the first reference measurement signal, the second reference measurement signal, and the attenuation coefficient corresponding to the attenuation. The single-photon detector is also used to acquire sensing measurement signals. The processor is also used to calibrate the sensing measurement signals based on the dead time. This optical fiber sensing system is used to detect the state of a target.

Systems and methods include generation of a first image volume based on electrical signals output by energy-integrating photon detectors, input of the first image volume to a network trained to generate a simulated photon-counting CT image from an energy-integrating CT image, reception of a first simulated photon-counting CT image generated by the network in response to the input first image volume, and presentation of the first simulated photon-counting CT image on the display.

The application discloses a single-photon source anti-bunching measurement device and method, relates to the technical field of single-photon detection, and comprises a single-photon source module, a signal trigger light path module, an interference light path module, a single-photon detector module and a coincidence counting module. The single-photon detector module comprises a first gated single-photon detector, a second gated single-photon detector, a first single-photon detector and a second single-photon detector, and can realize accurate measurement of the anti-bunching value of a deterministic single-photon source and a heralded single-photon source.

This application discloses a high-dimensional encoded quantum random number generator and a method for generating quantum random numbers. The high-dimensional encoded quantum random number generator includes an entangled photon source, a wavelength splitter, at least one photon encoding and detection module, and a data processing module. The photon encoding and detection module includes a first filter, a second filter, a dispersive device, a beam splitting module, a first photon detector, a second photon detector, and a third photon detector. This application uses multiple photon processing through the dispersive device and the beam splitting module to perform high-dimensional time encoding on a single photon. Under the condition of entangled photon pairs at the same rate, a single photon can be converted into a quantum random number with a higher number of bits, thereby improving the random number generation rate.

1. The name of the design product: fiber-coupled single-photon detector. 2. The use of the design product: weak light detection. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

A computing system can be configured for low-photon-count visual object classification. The computing system can include a photon-detection system that includes one or more cells. Each of the one or more cells can include one or more photon detectors. Each of the one or more photon detectors can be configured to output a photon signature in response to a photon incident on the one or more photon detectors. The computing system can include one or more processors and one or more storage devices storing computer-readable data. The data can include a low-photon-count classification model and one or more instructions that, when implemented, cause the one or more processors to perform operations for low-photon-count visual object recognition. The operations can include obtaining a photon signature from the photon-detection system. The operations can include providing the photon signature to the low-photon-count classification model. The operations can include determining, by the low-photon-count classification model, a classification of a visual object placed in a field of view of the photon-detection system based at least in part on the photon signature. The operations can include providing the classification as an output of the low-photon-count classification model.

A single Geiger avalanche photodiode pixel interconnected with a readout circuit is decomposed to form M * M parallel pixel structures, the M * M parallel pixel structures are connected to a single pixel input stage of the readout circuit, and the time complementation relation between pixel avalanche events is utilized to enlarge the pixel avalanche events. The detection probability of the array single-photon detector pixel is improved, the photon detection dynamic range is expanded, the upper limit of the pixel photon saturation counting rate of the array single-photon detector can be remarkably improved, and the method is applied to the fields of high-dynamic-range laser three-dimensional imaging, space laser communication and the like.

This invention provides a real-time ranging and positioning system and method based on an extended light source and a fast coincidence measurement algorithm. The real-time ranging system includes: an entangled light source, a first single-photon detector, a time-to-digital converter, a coincidence measurement module, a quantum transceiver module, and a corner mirror. The coincidence measurement module performs real-time coincidence measurement using a fast coincidence measurement algorithm based on the arrival time sequence of the signal beam and the arrival time sequence of the reference beam, obtaining the time difference corresponding to the peak position of the coincidence measurement curve. The distance between the target point and the real-time ranging system is then obtained based on this time difference. Furthermore, this invention splits the signal beam emitted by the light source into multiple signal sub-beams to form an extended light source, effectively reducing the cost of the measurement device while still satisfying quantum positioning measurement requirements.