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2193 results about "Phase modulation" patented technology

Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission. It encodes a message signal as variations in the instantaneous phase of a carrier wave. Phase modulation is one of the two principal forms of angle modulation, together with frequency modulation.

Modulation / demodulation method and wireless communication device using the same

To provide a modulation / demodulation method that can avoid overshoot that occurs during a signal point transition process on a constellation even when the Y-00 encryption communication method is applied to a modulation method used in wireless communication, and a wireless communication device using the method.SOLUTION: A modulation method using the Y-00 encryption communication method by phase modulation of information for wireless communication, includes determining a reference position in a constellation of a previous signal point indicating previously transmitted data, making a certain range determined by the reference position a prohibited area so that a transition path of the signal point avoids passing near the origin on the constellation, determining a relative position of the current signal point from the reference position based on a current running key and currently transmitted data within a range excluding the prohibited area, determining I / Q coordinates on the constellation from the current signal point to generate modulated data, and performing multi-value phase modulation.SELECTED DRAWING: Figure 11
Owner:HITACHI LTD

Quantum key delivery system, quantum key delivery method, and storage medium

A quantum key delivery system in which a first transmission device phase modulates a first polarization component of two orthogonal polarization components in transmitted light and modulates a second polarization component, which is the other polarization component, into a signal indicating the second random number sequence, based on a first random number sequence indicating the bit sequence to be transmitted and the second random number sequence indicating the base in the phase modulation of the bit sequence to be transmitted; and a second transmission device separates orthogonal polarization modes in the received light and extracts a clock timing from the signal indicating the second random number sequence.
Owner:NEC CORP

Target positioning method and system based on single reference station

The invention discloses a target positioning method and system based on a single reference station, and relates to the field of wireless positioning, and the method comprises the steps: generating vortex electromagnetic waves carrying orbital angular momentum based on a transmitting end of a reference station, and generating a time-varying phase modulation transmitting signal and a metasurface time-varying coding sequence through a programmable metasurface; a time-varying phase modulation emission signal forms a multipath superposition effect in a propagation environment, a receiving end obtains a mixed signal of a direct wave and a reflected wave, and the receiving end carries out OAM mode separation on the mixed signal of the direct wave and the reflected wave through a spiral phase plate and an annular array to obtain signal components in different modes; and based on the signal component and the metasurface time-varying coding sequence, reconstructing an equivalent virtual array response by adopting a compressed sensing algorithm. According to the invention, the orbital angular momentum modal separation technology and the metasurface dynamic coding technology are creatively fused, and high-precision real-time direction finding in a complex multi-path environment is realized under a single base station architecture.
Owner:XIAN XINCHEN ELECTRONIC TECH CO LTD

Method, device and equipment for automatically detecting optical loss of optical fiber connector

The invention relates to the technical field of optical fiber communication, and discloses an optical fiber connector optical loss automatic detection method, device and equipment, and the device comprises a modulation signal dynamic adjustment module, an environment parameter adaptive calibration module and a deep learning prediction model. The modulation signal dynamic adjustment module enhances the separability of optical fiber signals through dynamic phase modulation, and the detection precision is improved; the environmental parameter self-adaptive calibration module compensates the influence of temperature, humidity and vibration on optical signals in real time, and the stability of the system is improved; the deep learning prediction model is based on multi-dimensional data fusion and weight dynamic optimization, high-precision prediction of the performance degradation trend of the optical fiber connector is achieved, closed-loop logic from data collection to real-time prediction is formed, experiments show that the detection precision of the method can reach 99.2%, the prediction accuracy is improved to 93% or above, the optical loss calculation error is reduced to 1%, and the method can be widely applied to the field of optical fiber connectors. And meanwhile, the response speed is increased to millisecond level. The method is suitable for monitoring and predicting the optical fiber performance in a complex environment, and the precision and the real-time processing capability are remarkably improved.
Owner:SHENZHEN RIGAOXIN HARDWARE ELECTRONICS

Machine vision-based intelligent detection method for galvanized steel surface defects

The invention discloses a machine vision-based intelligent detection method for steel galvanized surface defects, which comprises the following steps: S1, acquiring and preprocessing a steel galvanized surface image to obtain a standardized image; s2, constructing a specular reflection probability graph according to the brightness distribution and the gradient magnitude, and calculating a reflection intensity value; s3, calculating a structure tensor matrix, determining a main direction angle and an anisotropic consistency coefficient, and generating a direction feature matrix; s4, establishing a multi-scale direction adaptive phase kernel function, and performing phase modulation in a frequency domain by adopting an improved phase stretching transformation algorithm; s5, inverse Fourier transform is executed, and a phase response matrix is extracted; s6, performing weighted fusion to obtain a comprehensive phase response diagram; and S7, setting a threshold value according to the noise variance and the statistical characteristics, executing binarization and morphological processing, and outputting a defect region and boundary coordinates. According to the invention, high-precision identification and boundary positioning of steel galvanized surface defects are realized.
Owner:SHANDONG CHUANGMEITE NEW MATERIALS CO LTD

Wind power grid-connected oscillation suppression method and system based on self-adaptive damping controller

The invention discloses a wind power grid-connected oscillation suppression method and system based on a self-adaptive damping controller, and relates to the technical field of oscillation suppression of a power system. According to the method, a self-adaptive damping controller structure is designed, and parameter setting is completed; then building a wind power grid-connected system simulation model; after voltage signals are collected, an FFT processing method is used for identifying oscillation frequency, and whether an unstable oscillation mode exists in the system or not is judged; if unstable oscillation exists, a self-adaptive damping controller is connected between the wind power plant side and the power grid side; the self-adaptive damping controller filters out signal components causing system oscillation and performs phase modulation; a signal component generated by the self-adaptive damping controller is injected into the power grid and counteracts with an original signal, and oscillation suppression is achieved. According to the self-adaptive damping controller designed by the invention, the oscillation frequency identification module and the phase shift parameter calculation module are introduced, so that measured data can be fully utilized, control link parameters are adjusted according to vibration frequency changes, and oscillation is effectively suppressed.
Owner:SOUTHEAST UNIV

Quantum key distribution secure communication system based on quantum mechanics principle

The invention relates to the technical field of quantum communication security, and discloses a quantum key distribution secure communication system based on a quantum mechanics principle. The system comprises a quantum state preparation unit which controls a quantum emission device to output a quantum state sequence containing a preset polarization angle and a phase modulation photon group; a quantum channel feature extraction unit captures channel environment interference parameters and constructs a photon polarization distribution matrix; a quantum communication security evaluation unit receives the matrix, and calculates a channel security coefficient threshold through a quantum bit error rate analyzer; the quantum key dynamic optimization unit generates an optimized key segmentation strategy in combination with a security coefficient threshold and a historical key negotiation record; the quantum key rotation control unit switches quantum state modulation parameters according to a segmentation strategy and a time window; and the quantum node synchronization management unit monitors node clock offset and injects a calibration signal to realize key distribution time slot alignment. The system can dynamically cope with environmental interference, and improves the security and adaptability of quantum key distribution.
Owner:PANZHIHUA UNIV

OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization

The invention provides an OTFS radar communication integrated signal processing method and system based on time-frequency-space domain joint optimization. According to the method, pilot symbol positions and densities are configured in an OTFS time-frequency grid according to channel time-varying characteristics and bandwidths, and a Doppler index range is set to optimize channel information acquisition; deploying a controllable reflecting surface, constructing a phase modulation matrix based on a target position and communication channel parameters, dynamically adjusting a phase gradient direction, and separating energy of a target echo and a communication signal; within a set Doppler index range, calculating frequency offset estimation, correcting a time domain sampling point of a received signal, and generating a phase correction vector; and positioning a spatial aliasing main interference area, and inhibiting symbol interference and spatial aliasing caused by a high-speed target through frequency domain beam forming weighting and phase rotation compensation in combination with a phase correction vector and a sub-Doppler parameter in the area. According to the invention, time-frequency-space domain cooperative efficient processing of OTFS radar communication integrated signals is realized.
Owner:BEIJING INST OF REMOTE SENSING EQUIP

Complex shell detection method and system based on structured light scanning

The invention relates to the technical field of detection, in particular to a complex shell detection method and system based on structured light scanning. The method comprises the following steps: calculating a wrapped phase value and a phase modulation amplitude of each pixel point under each frequency, calculating discrete probability distribution containing candidate stripe series and a corresponding probability for each pixel point based on a multi-frequency wrapped phase difference, generating an initial pixel confidence map, and constructing an energy function; the penalty weight of the smooth item is determined according to the phase modulation amplitude and the wrapped phase gradient local variance, obtaining an initial fringe order distribution diagram, updating discrete probability distribution by using an initial pixel confidence map, re-minimizing an energy function to obtain a corrected fringe order distribution diagram, and reconstructing a final three-dimensional shape. And iteratively optimizing a projector principal point and a radial distortion coefficient in system calibration parameters. According to the scheme, the geometric details of the surface can be reserved, and the processing effect and the measurement precision of the complex curved surface and the high-curvature area are improved.
Owner:ZHONGKE LIXIANG TECH CO LTD

Electromagnetic information metasurface multi-dimensional dynamic regulation and control system with intelligent optimized driving

The invention discloses an intelligent optimization driving electromagnetic information metasurface multi-dimensional dynamic regulation and control system, solves the problem that the function solidification of an existing metasurface is difficult to dynamically adjust, and belongs to the crossing field of electromagnetic metamaterials and intelligent control technologies. The method comprises the steps that a sensor network collects environment multi-dimensional information of a programmable metasurface unit in real time; the controller processes the environment multi-dimensional information to obtain a multi-dimensional sensing result; the multi-dimensional interaction layer inputs design parameters, the intelligent decision-making layer combines the design parameters and a multi-dimensional perception result to construct a target joint optimization model, reverse design is carried out on the super-surface array coding sequence, and a display array coding pattern and a three-dimensional radiation pattern / two-dimensional radiation pattern are obtained according to the designed super-surface array coding sequence; displaying on the multi-dimensional interaction layer; and the controller performs real-time electromagnetic response reconstruction and 1-bit or 2-bit phase modulation on the programmable metasurface unit through the field programmable gate array according to the designed metasurface array coding sequence.
Owner:HARBIN INST OF TECH

Interference mitigation using phase modification of an interference signal for a user equipment (UE)

In some aspects of the disclosure, an apparatus for wireless communication by a user equipment (UE) includes a primary receive (PRx) path associated with a first antenna and configured to receive a wireless signal. The apparatus further includes a diversity receive (DRx) path associated with a second antenna antenna. The apparatus further includes a phase shifter configured to phase-modify an interference signal from the second antenna based at least in part on a physical distance between the first antenna and the second antenna and further based on an angle of arrival (AoA) associated with the interference signal. The apparatus further includes a circuit configured to generate a received signal based on the wireless signal and the phase-modified interference signal.
Owner:QUALCOMM INC

Intelligent processing method and system for data of water treatment equipment based on cloud control

The invention discloses a water treatment equipment data intelligent processing method and system based on cloud control, particularly relates to the technical field of multi-stage water treatment process cooperative control, and is used for solving the problem of chained control failure caused by the fact that an existing cloud control system does not pre-judge a disturbance propagation path. The method comprises the following steps: establishing an inter-process-section hydraulic propagation correlation model which comprises a connection relation and a fluid transmission delay parameter; identifying a water inlet end water quality sudden change event type in real time; generating a time sequence path for propagating the mutation event to the downstream based on the model and the fluid flow rate; generating a dynamic response intensity factor of each process section according to the predicted time difference of arrival and fluid characteristics in the time sequence path; generating an energy attenuation factor according to the propagation distance and the pollutant type; generating a cooperative control instruction set by taking the dynamic response intensity factor as an amplitude constraint and the energy attenuation factor as a phase modulation parameter, and issuing the cooperative control instruction set to an edge end actuator; and global anti-disturbance cooperative control of a water treatment whole process chain is realized.
Owner:SHANGHAI ZHANGHUA FILM PURIFICATION

Wave plate polarization conversion-based light spot shaping device and use method

The invention discloses a light spot shaping device based on wave plate polarization conversion and a use method, and relates to the technical field of laser processing, the device divides random polarized light into S / P light through a first polarization beam splitter (PBS), converts the S light into P light through a first 1 / 2 wave plate, modulates the S light through a conventional silicon-based liquid crystal spatial light modulator (LCoS SLM), and converts the P light into the S light through a second 1 / 2 wave plate. And the beams are combined by the second PBS. The method comprises the steps of light splitting, polarization conversion, phase modulation, beam combining, beam expanding and focusing and the like. The double 1 / 2 wave plates are combined with the conventional PBS, the laser energy utilization rate is higher than 85%, commercial SLM equipment is adapted, the machining efficiency of the shaped annular light spots is remarkably improved compared with that of Gaussian beams, the method is suitable for laser welding and metal 3D printing, and the problems of energy waste and high cost are solved.
Owner:JIANXIN OPTOELECTRONICS (SUZHOU) CO LTD

Multi-source data-based selling point generation method for AI intelligent marketing

The invention discloses a multi-source data-based selling point generation method for AI intelligent marketing, and relates to the technical field of big data analysis and application, and the method comprises the following steps: obtaining a unified time scale matrix in a multi-source data access stage, building an extreme value inhibition prior based on the unified time scale matrix, and building an acquisition synchronization baseline; full-link time alignment is realized by collecting a synchronous base line; and acquiring an extreme value diagnosis fingerprint under the constraint of full-link time alignment, generating a threshold track based on a quantile residual spectrum and kurtosis skewness, and capturing and calibrating a burst extreme value by taking the threshold track as a dynamic reference. According to the method, a time sequence consistency basis is constructed, a data extreme value is accurately identified and corrected, the content is ensured to be true and credible in combination with causal correction and semantic screening, dynamic closed-loop optimization of content generation and delivery is realized through closed-loop feedback and phase regulation and control, and the authenticity, stability and compliance of AI marketing content are effectively improved.
Owner:SHANGHAI HAIPAI LINGKE CULTURE TECH CO LTD

Wide-spectrum narrow-linewidth semiconductor mode-locked laser

PendingCN120165292ALaser detailsLine widthGroup velocity dispersion
The invention belongs to the technical field of photoelectronics, and particularly relates to a wide-spectrum narrow-linewidth semiconductor mode-locked laser, and the collaboration of a saturable absorption region SA and a resonator is reflected in time domain-frequency domain dual optimization. And the resonator optimizes the frequency domain characteristics through nonlinear broadening, phase synchronization and mode purification. The SA adjusts a mode locking threshold value in real time through dynamic bias voltage, the pulse energy stability is ensured, dispersion management of the resonator balances the SPM and group velocity dispersion, spectrum splitting is avoided, and the dissipative soliton form is maintained. Besides, due to heterogeneous integration of the InP-based SA and the SiN-based resonator, wafer bonding of the InP-based SA and the SiN-based resonator is realized, high-efficiency energy transfer is realized through the low-loss conical waveguide, a high-performance frequency comb with a wide spectrum and a narrow pulse width is output, and the high-performance frequency comb can be widely applied to the fields of ultrafast optics, coherent light communication and precision spectroscopy.
Owner:SHANDONG UNIV

Fano resonance-based high-sensitivity acoustic sensor and measurement method

The invention relates to an optical acoustic sensor, in particular to a high-sensitivity acoustic sensor based on Fano resonance and a measuring method. The problem that an existing optical acoustic sensor is low in sensitivity is solved. A high-sensitivity acoustic sensor based on Fano resonance comprises a 1550nm laser, a phase modulator, a first polarization controller, a conical optical fiber, a CaF2 crystal resonant cavity, a second polarization controller, a photoelectric detector, an oscilloscope and a computer. The emergent end of the 1550nm laser is connected with the head end of the conical optical fiber through the phase modulator and the first polarization controller in sequence; the conical optical fiber is coupled with the CaF2 crystal resonant cavity; the tail end of the conical optical fiber is connected with the incident end of the photoelectric detector through the second polarization controller; the signal output end of the photoelectric detector is connected with the signal input end of the oscilloscope; the signal output end of the oscilloscope is connected with the signal input end of the computer. The method is suitable for acoustic signal measurement in the fields of industry, traffic, environmental protection, medical treatment and the like.
Owner:TAIYUAN UNIVERSITY OF TECHNOLOGY

Signal transmission link, signal calibration link, signal compensation link, signal transceiving link, integrated circuit, electromagnetic wave sensor, and device

The present disclosure relates to the technical field of electromagnetic wave sensors, in particular to a signal transmitting, calibration, compensation and transceiving links, an integrated circuit, an electromagnetic wave sensor and a device, wherein the transmitting link includes an analog signal source and a digital phase shifter, the analog signal source may be configured to provide an initial analog signal, and the digital phase shifter may be configured to provide a phase shift signal in a digital domain and to perform phase shifting on the initial analog signal based on the phase shift signal, so as to perform a preset phase shifting operation on the initial analog signal, thereby effectively improving the phase modulation resolution and phase modulation accuracy.
Owner:CALTERAH SEMICON TECH (SHANGHAI) CO LTD

Preparation method of barrier type antimonide infrared detector and infrared detector

The invention provides a preparation method of a barrier type antimonide infrared detector. The preparation method comprises the following steps: selecting a gallium antimonide substrate; a gallium antimonide buffer layer, an indium arsenide heavily-doped layer, a class II superlattice absorption layer and an aluminum-arsenic-antimony barrier layer are sequentially grown on the substrate in an epitaxial mode through a molecular beam epitaxy method; mechanically stripping the hexagonal boron nitride two-dimensional material, and transferring the stripped hexagonal boron nitride to the aluminum-arsenic-antimony barrier layer to form a Van der Waals heterojunction and composite barrier layer structure; depositing electrodes by using an ultraviolet lithography technology and a thermal evaporation mode to form one electrode arranged on the gallium antimonide buffer layer and the other electrode arranged on the boron nitride; a large-numerical-aperture micro-lens array is processed on a substrate, and the micro-lens array is composed of gallium antimonide cylinders with a phase modulation function; therefore, the antimonide medium-wave infrared detector with the composite barrier layer can be formed, the quantum efficiency is improved, the order of magnitude of dark current is reduced, and room-temperature medium-wave infrared detection can be realized.
Owner:CHINA ACADEMY OF SPACE TECHNOLOGY

Non-contact local curvature measurement method and system based on calculation metasurface

The invention discloses a non-contact local curvature measurement method and system based on a computational metasurface, and the method comprises the steps: S1, phase modulation: carrying out the phase modulation of an incident light field carrying the information of a to-be-measured object through an optical computational metasurface, so as to generate transverse displacement light field distribution related to the contour of the to-be-measured object; s2, signal extraction: separating and extracting a first-order differential signal carrying the edge information of the object to be measured by using a biorthogonal polarization filtering system; s3, reconstructing a three-dimensional shape: reconstructing the three-dimensional shape of the object to be measured according to the first-order differential signal; and S4, curvature calculation: calculating the curvature radius of any local part of the object to be measured according to the three-dimensional shape. The optical calculation metasurface is combined with a biorthogonal polarization filtering system, differential operation of a light field is achieved, the edge contour of an intensity object and the three-dimensional shape of a phase object can be obtained without difference, and therefore non-contact and high-precision measurement of the curvature of the object is achieved, the problem of physical damage of traditional contact type measurement is solved, and the measurement accuracy is improved. And the detection efficiency and adaptability are improved.
Owner:HUNAN UNIV

Multi-device rapid pairing and seamless screen projection switching system based on ultrasonic signals

The invention relates to the field of multi-device screen projection, in particular to a multi-device rapid pairing and seamless screen projection switching system based on ultrasonic signals, which comprises an ultrasonic processing module, a switching module, a data transmission module and an intelligent control processing module which are in wireless communication connection, wherein the ultrasonic processing module is used for transmitting and receiving ultrasonic signals through a phase modulation technology and a self-adaptive filtering technology, and pairing the ultrasonic signals; the switching module is used for switching screen projection connection after successful pairing; the data transmission module is used for establishing a temporary data transmission channel for data transmission; and the intelligent control processing module is used for receiving a screen projection request through a screen projection system optimization algorithm, a time window and a priority algorithm, and dynamically adjusting screen projection resource allocation. According to the invention, efficient pairing and switching of multiple devices can be realized, reliable information transmission and error correction are guaranteed, screen projection resource management and switching are more flexible, and good user experience and adaptability are improved.
Owner:GUANGZHOU LANGO ELECTRONICS TECH CO LTD

Integrated microcavity optical comb repetition frequency and optical frequency locking device and method

The invention relates to an integrated microcavity optical comb repetition frequency and optical frequency locking device and method, and belongs to the technical field of integrated microcavity optical combs. The locking device comprises a pumping module, a power amplification module, a phase modulation module, an electro-optic driving module, an acousto-optic modulation module, an acousto-optic driving module, a band-pass filtering module, a micro-ring resonant cavity and a beam splitting module; the device comprises a soliton detection module, a control module, a repetition frequency detection module, a first feedback control module, an acetylene frequency stabilized laser, a beat frequency module, an optical frequency beat frequency detection module and a second feedback control module. The locking device can achieve full frequency locking of the microcavity optical comb, has the advantages of being high in frequency stability, wide in servo bandwidth, simple and compact in structure, tight in locking, low in noise, high in reliability and low in cost, and can provide a powerful tool for the field of precision measurement.
Owner:CHINA ACAD OF AEROSPACE SCI & TECH INNOVATION

Dual electro-optic frequency comb-based laser tracking interferometric spatial coordinate measurement system and method

Disclosed in the present invention are a dual electro-optic frequency comb-based laser tracking interferometric spatial coordinate measurement system and method. Multiple target mirrors are identified by means of a vision module, to guide a rotating mirror to direct laser light toward each target mirror individually. A laser tracking interferometric ranging module obtains a tracking error of the laser beam deviating from the center of the target mirror to be used for closed-loop tracking control. A light source module outputs single-frequency laser light traceable to a gas absorption peak. By controlling a light source modulation module to enable or disable an electro-optic phase modulation drive signal, dual electro-optic frequency combs or dual-frequency continuous-wave laser light is outputted. In a tracking state, the laser tracking interferometric ranging module respectively uses the two light sources to measure the absolute distance and the relative displacement of a target mirror, and the real-time distance between the target mirror and an original point is computed by means of distance fusion; the elevation angle and the azimuth angle of the target mirror are obtained in real time by means of an azimuth angle and elevation angle measurement module; tracking control and coordinate computation are carried out by means of a tracking control and signal processing module and a computer, and finally three-dimensional spatial coordinates of all the target mirrors are measured.
Owner:ZHEJIANG SCI-TECH UNIV

Distributed feedback laser with double-layer grating structure

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.
Owner:XINCHEN SEMICON (SUZHOU) CO LTD

Optical cross system based on silicon-based liquid crystal and control method

The invention provides an optical cross system based on silicon-based liquid crystal and a control method, and relates to the field of optical elements, and the optical cross system comprises an optical fiber array, a micro lens array, a collimating lens, a polarization conversion module, a dispersion element, a focus lens group and a liquid crystal spatial light modulator. Optical signals are coupled through the micro-lens array, a divergence angle is compressed, and parallel light beams are formed through the double-agglutination collimating lens; the polarization conversion module separates the light beam into P / S polarized light and unifies the polarization state; the dispersion element separates light beams according to wavelength space, and the focus lens group forms an elliptical Gaussian light spot on the liquid crystal spatial light modulator; the liquid crystal spatial light modulator divides a light spot into a plurality of independent control areas in the long-axis direction, and single-wavelength multi-port output, power proportion regulation and control and monitoring signal extraction are achieved by dynamically modulating the reflection phase of each area. The control method comprises the steps of optical path processing, regionalized phase modulation and real-time monitoring feedback. According to the invention, flexible routing, power balance and lossless monitoring of wavelength channels can be realized.
Owner:BEIJING UNIV OF POSTS & TELECOMM +1

Electromagnetic field detector

This invention provides an electromagnetic field detector, a system comprising the electromagnetic field detector, and a method of operating an electromagnetic field detector, the electromagnetic field detector comprising a first optical signal interface configured to receive, from one or more remote optical sources, a first optical signal; an electromagnetic field transmitter configured to transmit a local oscillator electromagnetic field generated from the first optical signal, the electromagnetic field transmitter comprising: a photocurrent generator configured to generate a photocurrent from the first optical signal; and an antenna interface configured to supply the photocurrent to an antenna to transmit the local oscillator electromagnetic field; a second optical signal interface configured to receive, from the one or more remote optical sources, a probe optical signal and a coupling optical signal; and a transmission medium configured to be excited by the probe optical signal and further excited by the coupling optical signal, wherein the probe optical signal has a probe frequency set to excite electrons of the transmission medium to a first excited state and the coupling optical signal has a coupling frequency set to excite electrons of the transmission medium to a predetermined Rydberg state so as to induce an Electromagnetic Induced Transparency, EIT, effect, wherein the transmission medium is further configured to receive a phase-modulated electromagnetic field from a remote transmitter and the local oscillator electromagnetic field such that the combination of the phase-modulated electromagnetic field and the local oscillator electromagnetic field causes a change in the probe optical signal from which a phase state of the phase-modulated electromagnetic field can be detected.
Owner:BRITISH TELECOM PLC

Laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering

The invention discloses a laser frequency stabilization system based on Faraday anomalous dispersion atomic filtering, which is used for carrying out frequency stabilization on phase modulation multi-sideband laser, and comprises a frequency doubling laser unit which is configured to comprise a fundamental frequency seed light source, an electro-optical modulator, a fundamental frequency amplifier and a frequency doubling crystal; the light splitting module unit is configured to split the frequency doubling light into a main output light path and a monitoring light path; the atomic optical rotation filter is located on the monitoring light path and is configured to maintain the purity of the frequency-stabilized laser spectrum through purification treatment under the control of the axial magnetic field and the temperature; the frequency stabilization unit is configured to be a frequency stabilization light path and a servo system, and the frequency stabilization light path is used for obtaining laser frequency information and generating an error signal; the servo system is used for controlling the frequency of the fundamental frequency seed light source according to the error signal feedback. According to the laser frequency stabilization system provided by the invention, the spectrum purification and frequency stabilization precision can be improved, so that high-frequency stability locking is realized.
Owner:NATIONAL INSTITUTE OF METROLOGY CHINA

Non-contact concrete deformation testing system and method based on laser ranging technology

The invention is applicable to the technical field of concrete deformation measurement, and particularly relates to a non-contact concrete deformation testing system and method based on a laser ranging technology, and the system comprises a laser ranging unit which is provided with a double-frequency phase modulation laser, an optical transceiver antenna and a phase detection circuit; the environmental parameter acquisition unit comprises a temperature sensor, a humidity sensor and an air pressure sensor; and the data processing unit carries an atmospheric refractive index calculation module, a Kalman filtering algorithm and a three-level early warning module, and supports wired / wireless data transmission. The distance measurement precision is high, and the concrete micro-deformation monitoring requirement is met; non-contact characteristic: non-damage monitoring on the concrete surface is realized through a diffuse reflection target; intelligent data processing: structural deformation and environmental noise are effectively distinguished, and the early warning reliability is improved; automatic monitoring is achieved, and the manual inspection cost is greatly reduced.
Owner:INNER MONGOLIA UNIVERSITY

On-chip time frequency transmission system and method based on octave optical comb and electro-optical modulation optical comb, and photonic integrated chip

The invention discloses an on-chip time-frequency transmission system and method based on an octave optical comb and an electro-optical modulation optical comb, and the method comprises the steps: constructing a chip-based optical reference cavity through the technologies of vacuum optical cement, photoresist backflow and the like, and achieving an on-chip ultra-stable laser through a phase modulator and a reflection separation optical path; an on-chip laser source pumping micro-ring resonant cavity is utilized to generate an octave optical frequency comb, frequency multiplication is carried out on the on-chip laser source pumping micro-ring resonant cavity and an additional laser source to realize detection and locking of carrier envelope offset frequency (fceo), frequency beating is carried out on the on-chip laser source pumping micro-ring resonant cavity and the on-chip ultra-stable laser device to realize frequency beating (fbeam) locking, and the laser source is utilized to generate an electro-optical modulation optical frequency comb through a circulating phase modulator to realize frequency beating and locking of the on-chip ultra-stable laser device. And the optical time frequency is locked with the locked octave optical comb, is sent to a far end after polarization control and light amplification, and simultaneously receives an electro-optical modulation optical comb at the far end and performs linear light sampling, so that the transmission of the optical time frequency is realized. The optical fiber or space optical link time-frequency transmission device can realize optical fiber or space optical link time-frequency transmission, and has the advantages of low overall noise, high transmission precision, compact structure, small size, low power consumption and the like.
Owner:SHANGHAI JIAOTONG UNIV

Method and system for detecting mismatched harmonic waves of power amplifier and storage medium

The invention is suitable for the technical field of communication, and particularly relates to a method for detecting mismatched harmonic waves of a power amplifier. The method comprises the steps that a first power detection unit is connected with a coupler through a control unit, the standing-wave ratio of a to-be-detected power amplifier chip is adjusted to be 1: 1 through a tuner, and the power of an input signal of a vector signal generator is adjusted till the target power of the to-be-detected power amplifier chip is reached; the second power detection unit is connected with the coupler through the control unit, the output standing-wave ratio of the to-be-detected power amplifier chip is adjusted to a preset specific value through the tuner, and when the tuner modulates phases at intervals of preset degrees, the harmonic power of the to-be-detected power amplifier chip in each phase is recorded through the second power detection unit. Compared with the prior art, the method can accurately test and evaluate the harmonic wave of the to-be-tested power amplifier chip under the mismatched standing wave condition, thereby evaluating the harmonic wave index of the to-be-tested power amplifier chip.
Owner:LANSUS TECH INC

Energy storage type phase modifier control method, recording medium and system

The invention belongs to the technical field of power system operation and motors, and particularly relates to an energy storage type phase modifier control method which comprises the steps that a rotating shaft of a double-fed motor is connected with a flywheel to serve as an energy storage type phase modifier; the rotor winding is connected to a power grid through an excitation system and a transformer in sequence, and the excitation system is electrically connected by a reactor, a back-to-back converter and a filter in sequence; the stator winding is directly connected to a power grid; the control system decouples reactive power and active power, vector control is carried out on exciting current to absorb or release power, and reactive power-voltage support and active power-frequency support of the power grid are completed. The method overcomes the defects that a traditional direct-current excitation phase modulation mode can only modulate phase and cannot modulate frequency, or is cumbersome and slow in response. The system can meet the requirement of wide-range variable-speed operation, quickly store / release a large amount of rotor kinetic energy, inhibit the voltage and frequency fluctuation of a power grid, and is especially suitable for stations with high new energy occupation ratio. The invention also provides a non-transitory readable recording medium storing the program of the method and a system comprising the medium, and the program can be called through a processing circuit to execute the method.
Owner:WUHAN UNIV OF TECH