67 results about "Shot noise" patented technology

The invention discloses an anti-interference laser radar based on quantum noise and a ranging method, and belongs to the technical field of laser radars. Coherent state optical signals generated by a laser are split into signal light and local oscillation light through a beam splitter; random phase modulation is carried out on the signal light according to the true random number sequence, so that the phase difference between adjacent signal light is smaller than the vacuum shot noise; the signal light subjected to random phase modulation irradiates a target object after being expanded by the transmitting telescope, and echo signal light is formed after being reflected and enters the receiving telescope; performing coherent detection on the echo signal light by using a coherent detection module and local oscillation light, and generating initial data by collecting an output electric signal; and carrying out phase calculation on the initial data, generating demodulation data, and carrying out shift cross-correlation operation on the demodulation data and the true random number sequence to obtain a target distance. Only random phase modulation is needed, random amplitude modulation is not needed, an amplitude modulator is omitted, and the cost and complexity of the system are reduced.

The invention provides a CV-QKD real-time parameter estimation method and system for resisting local oscillation light intensity fluctuation, and the method comprises the steps: obtaining an initial shot noise calibration value through calibrating an LO intensity value before the start of a quantum key distribution process; in the quantum key distribution process, the received LO is subjected to beam splitting, the stronger path is used for coherent detection of quantum signal light, and the weaker path is used for LO intensity fluctuation monitoring; performing parameter estimation according to data obtained by coherent detection and the initial shot noise calibration value to obtain over-noise epsilon'and transmissivity T '; and according to the LO intensity fluctuation monitoring result, the LO intensity fluctuation monitoring result is considered in the parameter estimation process, and the over-noise epsilon'and the transmissivity T 'are corrected to obtain the over-noise epsilon and the transmissivity T close to the ideal LO condition. According to the method, the performance and the safety of the Gaussian modulation coherent state protocol CV-QKD system can be effectively improved.

A photon number resolving system includes: a plurality of pixels of which each includes a photoelectric conversion element and an amplifier for amplifying the electric charges converted by the photoelectric conversion element and converting the electric charges to a voltage; an A / D converter configured to convert a voltage output from the amplifier of each of the plurality of pixels to a digital value; a first deriving unit configured to derive a provisional value of a photon number in each pixel of the plurality of pixels based on the digital value; and a second deriving unit configured to derive a confirmed value of a photon number in a target pixel based on a first probability based on optical shot noise and a second probability based on reading noise.

The invention discloses an orchard unmanned aerial vehicle multispectral image noise restoration method based on a generative adversarial network, and relates to the technical field of multispectral image noise restoration, and the method comprises the steps: synthesizing a noisy sample containing stripes, photon particles, thermal noise, Rayleigh, shielding, compression artifacts, overexposure and waveband crosstalk on a noise-free reference image through a conditional generative adversarial network; a crosstalk matrix T obtained through optical calibration is introduced; based on the canopy / soil / sky semantic partition, main-cooperation-subdivision level superposition is implemented; generating hierarchical labels by taking energy conservation consistency and thermal noise correlation as thresholds; a branch and region self-adaptive repair module corresponding to classification is arranged in the image-to-image generative adversarial network, and joint loss training containing T regularization is adopted; and outputting the repaired image subjected to physical consistency checking. The method gives consideration to visual quality and spectral fidelity, inhibits cross-band pollution, improves the stability of indexes such as NDVI and NDRE, and is suitable for precision agricultural monitoring.

A quantum random number generator (QRNG) system including optocoupler including at least one light emitter and at least two light receivers that are electrically coupled to each other in a configuration that rejects common mode noise. The system also includes a controller configured to control the at least one light emitter to emit photons randomly towards the at least two light receivers, measure a shot noise signal generated by the at least two light receivers in response to receiving the photons, and extract a random number from the shot noise signal.

The invention discloses a noise model obtaining method, a denoising neural network training method, a noise model obtaining device, a denoising neural network training device, electronic equipment and a computer readable storage medium, and the noise model obtaining method comprises the steps: shooting a flat field frame under different sensitivities and different light incoming amounts, modeling shot noise NP, and obtaining a noise model NP; the relation between the ISO and the system gain K is calibrated; shooting dark field frames under different ISOs, and modeling black level error noise NBLE to calibrate the black level error noise under different ISOs; modeling row noise Nrow and calibrating the relationship between different ISO and the noise parameter sigma row; modeling a fixed pattern noise (NFPN); modeling and reading noise Nread, and calibrating the relationship between different ISO and the shape parameter lambda and the noise intensity sigma TL; and obtaining a target noise model according to the model of the NP, the relationship between the ISO and the system gain K, the model of the NBLE, the model of the Nrow, the relationship between the different ISO and the sigma row, the model of the NFPN, the model of the Nread and the relationship between the different ISO and the shape parameters lambda and sigma TL.

The invention relates to the technical field of image processing and extremely weak light imaging, and particularly provides a photon counting image reconstruction method and system, and the method comprises the steps: determining a target threshold value based on the adjustment of a dynamic adjustment coefficient under different illumination or gain conditions based on an initial threshold value; counting a first photon number of a single photon signal in the background image and a second photon number of the single photon signal in the signal image based on a target threshold, and generating noise photon number statistical distribution and signal photon number statistical distribution to determine a dynamic photon number processing interval; and performing time-space joint accumulation on the pixels conforming to the dynamic photon number processing interval, generating a two-dimensional photon accumulation matrix, and converting the two-dimensional photon accumulation matrix into a gray level image to form a single group of reconstructed gray level images. According to the method, real signals can be effectively extracted, the influence of dark noise, shot noise and readout noise is suppressed, zero noise detection is realized, and finally, the dynamic range, the signal-to-noise ratio and the stability of the image are remarkably improved through single-group image reconstruction and multi-group integration processing.

The present application relates to a noise model estimation method, device, computer equipment, storage medium and computer program product. The method comprises: obtaining a plurality of first RAW images captured by a camera at different gain values ​​in a dark environment, and determining a read noise model according to the plurality of first RAW images; in a light environment, outputting the read noise of each second RAW image through the read noise model; each second RAW image is captured by the camera at different gain values; determining a shot noise model based on each second RAW image and the read noise corresponding to each second RAW image; and obtaining a target noise model of the RAW image captured by the camera based on the read noise model and the shot noise model. The use of this method can improve the accuracy of the estimated noise model.

The utility model relates to a teaching instrument for measuring Boltzmann constants and electronic charges through a noise method. The teaching instrument comprises an amplifier, a change-over switch, a resistance box, a shot noise measuring device, an analog-to-digital converter and a data processing device. The fixed end of the change-over switch is electrically connected with the input end of the amplifier; a semiconductor device is arranged in the shot noise measuring device, and the switching end of the change-over switch is used for switching between the measuring end of the resistor box and the measuring end of the shot noise measuring device; the analog-to-digital converter is electrically connected with the output end of the amplifier; the input end of the data processing device is electrically connected with the output end of the analog-to-digital converter. The circuit noise is used for measuring the Boltzmann constant and the electronic charge, the data measurement object is only voltage data, the operation is simple, the learning demand of students on the circuit noise is met, and the market demand of such teaching instruments except the PN junction measurement principle is filled up. According to the teaching instrument, integrated experimental equipment is used, and two different college physics experiments can be carried out only by replacing a circuit.

Collected light may be split into fields using grazing incidence mirrors to avoid illuminating gaps between the active areas for readout electronics. The grazing incidence mirrors may reduce lost field space in the integrating direction by splitting the imaging field in that direction to allow the readout electronics to be outside of the field. The fields may be split so there is space for readout circuits but no associated light on the readout circuits. The size of the illumination may then be decreased and / or the number and / or size of sensors increased to improve the photon collection efficiency. The better photon collection efficiency may reduce shot noise and / or improves tool throughput.

The present application relates to the technical field of quantum sensing based on atomic cell, in particular to a light glue inner mirror surface reflection multi-optical path atomic cell and application thereof. The light glue inner mirror surface reflection multi-optical path atomic cell of the present application increases the optical path of the probe laser in the atomic cell cavity and amplifies the signal without changing the size of the spectral analysis cell chamber; ultimately, the fundamental sensitivity of the measurement is limited by the quantum shot noise of the atoms, and the limit of such sensitivity is called the standard quantum limit, which is inversely proportional to the square root of the number of atoms simultaneously detected in the chamber. The multi-optical path design of the light glue inner mirror surface reflection multi-optical path atomic cell of the present application can make the probe laser cover the entire cross section of the atomic cell cavity and simultaneously detect almost all the atoms in the atomic cell cavity, thereby greatly improving the signal-to-noise ratio of the measurement and the sensitivity under the standard quantum limit caused by the shot noise.

The present invention proposes a code rate analysis method based on non-ideal Bell detection in continuous variable measurement device-independent quantum key distribution. The system implementing the method mainly includes continuous laser sources at Alice and Bob ends, a pulse modulation module, a Gaussian modulation module, an optical attenuator, and a polarization multiplexing module. The polarization demultiplexing module, an optical collimator, and a balanced homodyne detector at Charlie end. The steps of the method are: Step 1: Alice and Bob ends prepare Gaussian coherent states; Step 2: Charlie end performs Bell measurement; Step 3: Shot noise normalization of measurement data; Step 4: Phase compensation of measurement data; Step 5: Measurement angle error estimation; Step 6: Measurement angle error compensation. Step 7: Calculate and generate a security key. In practical applications, due to the non-ideality of the phase modulator, non-ideal Bell detection at the Charlie end will occur, resulting in a reduction in the system code rate. The present invention can compensate for the angle error during measurement, achieve ideal Bell detection, and improve the security code rate of the system.

The invention belongs to the technical field of commercial cipher system testing, and particularly relates to a quantum random number generator-based commercial cipher system entropy source quality detection method, which comprises the following steps of: acquiring shot noise of a light quantum detector at a high sampling rate, removing direct current bias by using a moving average subtraction method, and acquiring a quantum fluctuation sequence of a zero mean value; based on a variance ratio of the sequence and short-range autocorrelation, nonlinear mapping of an exponential function is utilized to obtain correlation degree so as to amplify a weak non-quantum memory effect; obtaining an evaluation model containing hyperbolic cosine and a logarithmic function by combining the drift potential energy of the bias voltage relative to the target value and the aging time of the device, and obtaining a dynamic entropy loss index; and comparing the entropy loss index with a preset threshold value, and executing self-adaptive bias current feedback regulation or triggering hardware fusing according to a comparison result. According to the invention, the problem of recessive degradation of the entropy source caused by drifting of the working point of the detector is solved, and accurate closed-loop control of the quality of the entropy source is realized.

A degenerate four-wave mixing (DFWM) squeezed light apparatus includes one or more pump beams, a probe beam, a vapor cell, a repump beam, and a detector. The one or more pump beams includes an input power of no greater than about 150 mW. The vapor cell includes an atomic vapor configured to interact with overlapped pump and probe beams to generate an amplified probe beam and a conjugate beam. The repump beam is configured to optically pump the atomic vapor to a ground state and decrease atomic decoherence of the atomic vapor. The detector is configured to measure squeezing due to quantum correlations between the amplified probe beam and the conjugate beam. The one or more pump beams, the probe beam, and the repump beam are configured to generate two-mode squeezed light by DFWM with squeezing of at least 3 dB below shot noise.

The invention discloses an electric signal demodulation method of a single-light-source single-axis fiber-optic gyroscope, and relates to the technical field of quantum optical precision measurement, and the method comprises the following steps: constructing a joint probability density function model of quantum fluctuation noise, dynamically correcting actually measured noise parameters through Bayesian inference, and generating a noise model containing shot noise variance and thermal noise mean; generating a plurality of groups of reference-measurement light path pairs by using Y waveguide beam splitting characteristics, calculating interference signal cross correlation coefficients of each group of light path pairs, and screening out two groups of high correlation signal pairs with the highest correlation degree; and according to the high-precision phase track, based on a phase-angular velocity conversion relation of a Sagnac effect, calculating a rotation angular velocity value by applying a Sagnac phase shift formula, and outputting the rotation angular velocity value. According to the invention, through dynamic noise modeling and a parameter adaptive adjustment mechanism, shot noise and thermal noise are efficiently suppressed, and the integrity and accuracy of the phase signal after noise reduction are remarkably improved.

A real-time spin state detection method based on diamond NV color centers uses the Bayesian estimation theorem and fully utilizes the noisy fluorescence intensity obtained during diamond NV color center detection to achieve real-time updated detection of the first energy level population of the electron spin state ground state. This calculated first energy level population value is used as the final spin state estimation result until it stops changing. This method suppresses photon shot noise and achieves real-time spin state detection, while being simple to operate and easy to implement.

The invention discloses a quantum enhanced vector magnetic field gradient detection method and device, and the method comprises the steps: generating two pairs of intensity-related twin beams through a nonlinear effect-four-wave mixing, and further constructing a pair of continuous multi-dimensional polarization entangled beams from the twin beams through a linear polarization beam splitter, i.e., carrying out the idler frequency light and signal light as detection light, respectively inputting a pair of atom sensors to realize vector magnetic field measurement. According to the invention, the continuous multi-dimensional polarization entangled light source is formed by splitting and combining twin beams, so that the intensity and direction of a vector magnetic field are accurately measured, and meanwhile, shot noise and common-mode magnetic field noise of light are remarkably reduced.

The present application belongs to the technical field of commercial cipher system test, and particularly relates to a method for detecting the quality of an entropy source of a commercial cipher system based on a quantum random number generator, which comprises: obtaining shot noise of an optical quantum detector at a high sampling rate, removing direct current bias by using sliding average subtraction, and obtaining a quantum fluctuation sequence with zero mean; obtaining a correlation degree by using nonlinear mapping of an exponential function based on the variance ratio and short-range autocorrelation of the sequence, so as to amplify weak non-quantum memory effects; obtaining an evaluation model containing a hyperbolic cosine and a logarithmic function by combining the drift potential of a bias voltage relative to a target value and the aging time of a device, so as to obtain a dynamic entropy loss index; and comparing the entropy loss index with a preset threshold value, and performing adaptive bias current feedback adjustment or triggering hardware fusing according to the comparison result. The present application solves the problem of implicit degradation of an entropy source caused by drift of a detector operating point, and realizes precise closed-loop control of the quality of the entropy source.

The invention discloses an all-normal dispersion super-continuum spectrum driven resonant optical gyroscope and a working method thereof, and belongs to the field of optical gyroscopes. The input end of the mode-locked laser ML is connected to a left port of the full-normal dispersion photonic crystal fiber ANDi-PCF, input ports of the full-normal dispersion photonic crystal fiber ANDi-PCF and the photoelectric detector PD are connected to two left ports of the circulator CIR respectively, and a right port of the circulator CIR is connected with a left port of the multifunctional integrated optical chip MIOC. And two ports on the right side of the multifunctional integrated optical chip MIOC are respectively connected with two ports of the waveguide ring resonator WRR. Based on the resonance mode of the full-normal dispersion super-continuum spectrum excitation waveguide ring resonator, the influence of relative intensity noise and shot noise on the gyroscope performance is further reduced by using the broadband and smooth light source spectrum pattern, and finally the angle random walk of the gyroscope is promoted.

The embodiment of the invention provides a sample image generation method and device, a model training method and device, equipment and a medium. The method comprises the steps of obtaining a noiseless image and a target image shot by a camera; predicting noise parameters of the camera based on the features of the target image; adding shot noise, readout noise and row noise in the noiseless image according to the noise parameters to obtain a noise image; and determining the noiseless image and the noise image as sample images corresponding to the camera. The electronic equipment can realize automatic generation of the sample image by predicting the noise parameter and adding the noise based on the predicted noise parameter, and the efficiency of obtaining the sample image is improved. Moreover, a large number of noise images can be generated on the basis of a public noiseless image only through one image shot by a camera, and the cost of obtaining a sample image is reduced. In addition, a noise image generated by adding the most important noise in three types of real images including shot noise, readout noise and row noise can be well fit with a real noise image.

The invention relates to the technical field of network security communication, in particular to a wireless network camera mainboard security communication protocol optimization method and system, and the method comprises the following steps: reading a signal-to-noise ratio and a signal intensity numerical value, calculating a link quality score, capturing photoelectric shot noise, converting the photoelectric shot noise into a true random entropy source sequence, and carrying out the real random entropy source sequence; generating a dynamic session key in combination with clock jitter; analyzing the monitoring video stream to separate an I frame and a P frame, when the score is lower than a threshold value, only encrypting the I frame to generate a core ciphertext, and generating an integrity check code for the P frame; and constructing a security protocol data frame according to the error correction coding rate and executing a data transmission action. According to the method, the encryption density of the video data is dynamically adjusted according to the signal-to-noise ratio of a real-time signal by introducing a dynamic fragmentation mechanism of channel state perception, so that the calculation overhead of a mainboard in a weak network environment is effectively reduced, and the traditional complete handshake process is replaced by lightweight re-authentication logic based on hardware noise characteristics; and the problem of picture interruption caused by frequent reconnection is fundamentally eliminated.

This invention relates to the field of ultrasensitive magnetic measurement technology based on quantum sensing, and in particular to a single-beam zero-magnetic-field dual-axis vector magnetometer and its usage and applications. This invention employs a single probe laser beam to simultaneously perform pumping and detection functions, and innovatively combines the tensor-vector polar moment conversion (AOC) effect, magnetic field modulation, and large-amplitude modulation of the optical frequency. This significantly reduces the resonant linewidth of the magnetometer while suppressing photon shot noise and detector electronic noise, and achieves dual-axis magnetic field measurement in a zero-magnetic environment. In laboratory desktop experiments, a sensitivity of level 10 can be achieved.

A detector can include a group of orthogonally oriented quantum detectors, wherein each quantum detector among the group of orthogonally oriented quantum detectors can detect variations in a quantum field. The detector can further include a signal processor that can determine a direction and magnitude of the detected quantum field variations based on outputs from the group of orthogonally oriented quantum detectors. Each quantum detector among the group of orthogonally oriented quantum detectors can include an array of Zener diodes biased to produce shot noise modulated by quantum field variations. The detector can constitute a three-dimensional quantum field detector. In some embodiments, a tunneling sensor comprising a tunneling capacitor may be implemented in place of Zener diode.

At least one sample parameter of a sample (16) is measured using measuring light. The measuring light is split into sample measuring light and reference measuring light. The sample measuring light interacts with the sample (16), generating modified measuring light with a phase and / or intensity dependent on the sample parameter. The modified measuring light and the reference measuring light overlap to interfere, generating signal light, and the intensity of the signal light is measured. A tuning parameter (t1, t2, t1', t2', t1'', ​​t2'') is determined from the intensity of the signal light and used to control a phase and / or intensity tuner (20, 32, 52, 70', 70'') to make the interference destructive and thus minimize or at least reduce the measured intensity. The sample parameter is determined based on the intensity parameter and / or the tuning parameter. This technique reduces shot noise.It can be used in a variety of applications, but a particularly preferred application is stimulated Raman scattering or NIR reflection / absorption spectroscopy.

The present application relates to the technical field of quantum sensing based on atomic cell, in particular to a light cement total reflection multi-optical path atomic cell and its application. The light cement total reflection multi-optical path atomic cell comprises an atomic cell cavity, a window sheet and a right-angle prism; two side opening positions of the atomic cell cavity are provided with the window sheet, the window sheet is connected with the atomic cell cavity by light cement, and the side of the window sheet away from the atomic cell cavity is provided with the right-angle prism allowing multiple reflections of the probe laser; the window sheet is provided with an entrance and an exit allowing the probe laser to enter and exit. In use, the probe laser beam is totally reflected back and forth between the two right-angle prisms and passes through the atomic cell cavity multiple times; the atomic cell cavity allows the light intensity of the probe laser to be uniformly distributed in the atomic cell cavity, so that almost all the atoms in the atomic cell cavity can be detected at the same time, thereby improving the detection signal intensity and the sensitivity under the standard quantum limit determined by the atomic shot noise.

The invention discloses a wireless light transmission method based on characteristic value gradient distribution and a large-view-field MPPC array, and relates to the technical field of visible light communication. The method comprises the following steps: constructing an MPPC array receiving system, and adjusting a receiving signal-to-noise ratio by adjusting an array position; an array receiving self-identification merging algorithm is adopted to extract edge power gradient features and fuse signals; establishing a pixel channel model containing received signal power, environmental noise and shot noise; analyzing channel gradient change and calculating edge parameters; an EIGD algorithm is applied to allocate channel weights to balance noise suppression and signal enhancement; constructing a receiving model and calculating an output signal-to-noise ratio; and error code analysis and algorithm performance comparison are carried out. According to the method, the signal detection efficiency under low illumination is improved through the EIGD algorithm, the robustness is prominent in a low signal-to-noise ratio or dynamic environment, and the requirements of unmanned aerial vehicle communication for high-speed and reliable transmission are met.

A method of operating a resonator optical gyroscope includes generating optical signals having a broadband frequency range. The method includes coupling the optical signals into an optical resonator (OR) to propagate in a first direction and coupling the optical signals out of the OR after the optical signals pass through the OR in the first direction. The method includes coupling optical signals into the OR to propagate in a second direction and coupling optical signals out of the OR after the optical signals pass through the OR in the second direction. The method includes amplifying the optical signals coupled out of the OR by the second optical coupler or the optical signals coupled out of the OR by the first optical coupler to generate amplified optical signals and generating electrical signals corresponding to the amplified optical signals. The method includes determining a rotation rate based on the electrical signals.

The invention discloses a waveguide coupled nonlinear transmission line terahertz heterodyne detector structure. The structure comprises a waveguide structure used for collecting terahertz input signals; the microstrip transmission line is used for coupling and transmitting a terahertz input signal into the frequency mixer; the terahertz frequency mixer is used for performing heterodyne frequency mixing to obtain a terahertz response signal; the filter structure is used for isolating the terahertz response signal; the lead electrode structure is used for providing power supply voltage and outputting a terahertz response signal; wherein the terahertz frequency mixer comprises a variable capacitance diode and a coplanar waveguide transmission line, and the variable capacitance diode and the coplanar waveguide transmission line are matched to form a nonlinear transmission line. According to the invention, the variable capacitance diode is used as the mixer, shot noise is fundamentally suppressed, so that the device has the advantage of high sensitivity, the technical scheme of the NLTL is adopted, the device has the broadband characteristic, in addition, the scheme of waveguide coupling is adopted, terahertz light is incident from a waveguide port, the stability is high, and the device has high coupling efficiency.

A quantum random number generator (QRNG) system including an optical coupler, the optical coupler including at least one light emitter and at least two light receivers, the at least two light receivers being electrically coupled to each other in a configuration that suppresses common mode noise. The system also includes a controller configured to control the at least one light emitter to randomly emit photons to the at least two light receivers, measure shot noise signals generated by the at least two light receivers in response to receiving photons, and extract random numbers from the shot noise signals.

An inspection system includes a controller including one or more processors configured to execute program instructions. The program instructions cause the one or more processors to receive at least a first portion of a first set of repeat swaths of a first scan path of a sample. The program instructions cause the one or more processors to generate an image by averaging the first portion of the first set of repeat swaths. Averaging the first portion of the first set of repeat swaths reduces a noise in the image. The program instructions cause the one or more processors to detect one or more defects in an inspection region of the sample using the image.