198 results about "Brillouin scattering" patented technology

The invention provides a comprehensive pipe gallery structure health monitoring system based on distributed optical fiber sensing, and relates to the technical field of engineering detection, and the system comprises a laying module which is used for laying an optical fiber sensing optical cable with waterproof and anti-corrosion performances in a pipe gallery structure, setting a positioning reference point and a coordinate calibration reference point in the central area of the tops of the two ends of a pipe gallery, and setting a positioning reference point and a coordinate calibration reference point; a linear reference system covering the length of the whole pipe gallery is constructed; and the acquisition module is used for connecting the optical fiber sensing optical cable with the distributed optical fiber temperature measuring device and the distributed optical fiber strain device, and acquiring temperature distribution data and strain distribution data in the pipe gallery based on Raman scattering and Brillouin scattering principles to form a monitoring data set. According to the invention, the temperature and strain multi-dimensional data of the pipe gallery are collected in real time through the distributed optical fiber sensing technology, and the structure health monitoring is realized in combination with redundancy monitoring, dynamic compensation and an intelligent early warning mechanism.

The invention provides a tunnel deformation parameter inversion method and device based on distributed optical fibers, and relates to the technical field of tunnel deformation parameter inversion, and the method specifically comprises the steps: selecting a monitoring point in a tunnel, arranging an optical fiber sensor, and obtaining a Brillouin scattering signal generated by the optical fiber sensor under the stress effect of the corresponding monitoring point; extracting a Brillouin frequency shift corresponding to the monitoring point, and determining an environmental effect frequency shift correction value by using the temperature change data, the humidity change data and the service time of the optical fiber sensor; determining the structural strain of the monitoring point according to the Brillouin frequency shift and the environmental effect frequency shift correction value, generating a three-dimensional strain field cloud picture, performing spatial registration on the three-dimensional strain field cloud picture and the geometric topology of the model, and performing three-dimensional grid division; the structure strain of the monitoring point is mapped to the grid node at the corresponding position, the structure strain of other grid nodes is determined based on the space distance attenuation law, inversion of the whole tunnel deformation parameters is completed, and the tunnel deformation monitoring precision and efficiency are improved.

The invention discloses an automobile wire harness parameter performance test method and system, and relates to the field of intelligent monitoring and predictive protection of electrical equipment, and the method comprises the steps: extracting the trend intensity, fluctuation characteristics and abnormal frequency of resistance change based on a high-precision micro-resistance change rate data stream, and carrying out the fusion to generate a three-dimensional characteristic electric pulse signal; according to the three-dimensional characteristic electric pulse signal, a decision result is converted into a control instruction to drive an execution mechanism to execute safety diagnosis regulation and control, and an equipment operation log is generated; based on an equipment operation log, positioning an overheat area by combining a Brillouin scattering principle, measuring dielectric loss change of an insulating material, and generating a diagnosis verification report; according to the diagnosis verification report and the decision result, the neural pathway connection weight is dynamically optimized, and a wire harness performance report is generated; intelligent extraction and compression coding of resistance change characteristics under complex working conditions are realized by adaptively adjusting threshold control parameters, and three-level response decisions are driven to complete fault grading judgment and execution in a millisecond-level time window.

A lidar system and an inversion method for simultaneously detecting carbon sequestration efficiency of the oceanic biological pump and ocean environmental dynamic parameters. The information of Mie scattering and Brillouin scattering intensity and the information of frequency shift and linewidth of Brillouin scattering spectra are combined, and for the detection requirements of the current ocean carbon cycle and dynamic environmental parameters, the vertical profile distribution of the carbon cycle mechanism and environmental dynamic parameters in the euphotic layer is mainly detected; at the same time, the present disclosure constructs an inversion model of the carbon sequestration efficiency of the oceanic biological pump and the temperature and salinity of the environmental dynamic parameters and realizes the synchronous detection of the carbon sequestration efficiency of the oceanic biological pump and the vertical profile distribution of the ocean environmental dynamic parameters in the euphotic layer.

The invention provides an intelligent optical cable performance prediction method and system for a data center, and relates to the technical field of data center performance analys.The intelligent optical cable performance prediction method comprises the steps that firstly, an optical cable microstructure disturbance quantization model is constructed, and an optical cable is divided into a plurality of virtual quantization units in the longitudinal direction; each unit packages a real-time stress-strain state parameter and a response sensitivity coefficient of the basic structure unit, inputting a Brillouin scattering spectrum frequency shift data flow collected in real time into the model for disturbance source analysis, generating a physical excitation decomposition sequence, driving a virtual quantization unit to perform state evolution iterative operation according to the physical excitation decomposition sequence, and obtaining a Brillouin scattering spectrum frequency shift data flow model; a stress-strain state evolution track set is obtained, a time-space correlation network of optical cable link disturbance propagation is constructed according to the stress-strain state evolution track set, network flow characteristic analysis is conducted on the time-space correlation network, an early warning node set is extracted, the future evolution trend of the early warning node set is calculated, and serialized optical cable performance abnormity early warning information is generated. The optical cable performance abnormity can be predicted in advance, and stable operation of the data center optical cable is guaranteed.

The invention relates to a pile foundation deformation indirect monitoring device and method based on optical fiber sensing, the device comprises a counterweight guide hammer, a steel wire rope, a distributed sensing optical fiber and a BOTDA optical signal demodulation device, the counterweight guide hammer is used for guiding the distributed sensing optical fiber to enter a drill hole, the steel wire rope is bound and connected with the counterweight guide hammer through a hanging ring above the counterweight guide hammer, and the BOTDA optical signal demodulation device is connected with the BOTDA optical signal demodulation device. The BOTDA optical signal demodulation equipment is used for pulling a counterweight guide hammer, the distributed sensing optical fiber comprises a connecting section, a measuring section I, a measuring section II, an optical signal input section and an optical signal output section, and the BOTDA optical signal demodulation equipment is used for collecting and analyzing an output Brillouin scattering light signal; the method comprises the following steps: 1, laying measuring points; 2, strain conversion; 3, geometric transformation; and 4, mechanical conversion. The device solves the limitation that the existing monitoring technology cannot carry out nondestructive testing on the existing pile foundation, and is simple in structural design, efficient in layout and easy to popularize.

The invention belongs to the technical field of communication, and provides a communication optical cable state real-time online monitoring method and system. Calculating the vibration displacement of the optical cable based on the original back scattering light signal, and calculating the real strain and temperature of the optical cable based on a Brillouin scattering signal and a Raman scattering signal obtained by separating the original back scattering light signal; carrying out filtering, denoising, normalization and time-space alignment processing on the vibration displacement of the optical cable, the real strain of the optical cable and the temperature, and binding the vibration displacement and the real strain with the obtained geographic coordinates; obtaining time domain, frequency domain and time-frequency domain features based on the preprocessed vibration displacement, real strain and temperature data to form a multi-dimensional feature vector, inputting the feature vector into a pre-trained event recognition model, and outputting an abnormal event classification result; and judging and triggering abnormal event early warning based on an output result of the event recognition model and a preset dynamic threshold.

The invention discloses a system for simultaneously measuring temperature and pressure based on forward Brillouin scattering in a multi-core optical fiber, which relates to the technical field of optical fiber temperature and pressure double-parameter sensors, and is characterized in that light emitted by a pump light source enters a polarization controller after being modulated by a pump light modulation system, and then enters an erbium-doped optical fiber amplifier; one part is injected into a Sagnac ring, and the other part excites a high-order torsion-radial mode through a multi-core optical fiber; light emitted by the detection light source is divided into light beams transmitted in the clockwise direction and the anticlockwise direction through the coupler, and the light beams are injected into the Sagnac ring; the spectrum analyzer captures the frequency shift of the Brillouin scattering signal; the signal processing unit processes the frequency shift of the Brillouin scattering signal and inverts temperature and strain data; and the data analysis and feedback system is combined with machine learning to optimize temperature and strain data. According to the invention, high-sensitivity temperature and strain sensing is realized.

A dry-type reactor turn-to-turn fault monitoring method based on a distributed optical fiber measurement temperature change rate is characterized in that a dry-type hollow series reactor finite element simulation model is built, and temperature distribution during normal operation and turn-to-turn short circuit faults of the dry-type hollow series reactor is acquired. Based on a distributed optical fiber sensing temperature measurement technology of Brillouin scattering, path temperature information in a reactor package is extracted, temperature data after normal operation and turn-to-turn short circuit are compared, and influences of different factors on fault temperature are explored. The early warning method for monitoring the turn-to-turn short circuit fault of the dry-type air-core reactor is provided by taking the temperature change rate as a criterion, and the influence of different factors on the effectiveness of the early warning method is verified. The result shows that the environment temperature, the wind speed and the running current basically have no influence on the method for monitoring the turn-to-turn short circuit of the dry-type air-core reactor by taking the temperature change rate as the criterion, different temperature change rate thresholds need to be set under different sampling intervals, and the smaller the sampling interval is, the larger the threshold is.

The invention particularly relates to an excitation signal waveform intelligent optimization method for a high-power narrow-linewidth fiber laser, and the method comprises the steps: obtaining an excitation signal, carrying out the processing of a phase modulation waveform of the excitation signal, and extracting an input feature set needed by frequency spectrum prediction; constructing a frequency spectrum prediction model based on the decoupling echo state network, inputting the input features into the frequency spectrum prediction model based on the decoupling echo state network, realizing nonlinear mapping between the phase modulation waveform of the excitation signal and the frequency spectrum response thereof, and obtaining a prediction frequency spectrum; constructing a composite cost function including a mean square error, a spectrum sideband leakage penalty term and a spectrum smoothing term based on the difference between the predicted spectrum and the target spectrum; based on a composite cost function, an Adam optimization algorithm is adopted to iteratively correct a phase waveform in a frequency domain, intelligent waveform optimization of phase modulation is realized, and a threshold value of a stimulated Brillouin scattering effect is reduced. The intelligent optimization of the phase modulation waveform of the excitation signal can be realized.

The invention provides a Brillouin frequency shift extraction method and device, equipment and a storage medium, and relates to the technical field of optical fiber sensing, and the method comprises the steps: carrying out the algebraic conversion of a measured Brillouin scattering gain spectrum into a Brillouin center frequency curve; according to the Brillouin center frequency curve, the approximate value of the center frequency of the maximum value position of the Brillouin scattering gain spectrum is solved, then the center frequency of the Brillouin scattering gain spectrum is determined, that is, a frequency shift extraction result is given in a multi-center-frequency statistical mode, and the method has the advantages of being high in precision and stability. Meanwhile, a fitting tool does not need to be used in the calculation process, and the calculation complexity is extremely low; compared with the prior art, the method provided by the invention has the advantages that the method is not easily influenced by a multi-peak Brillouin form, and particularly, a high-precision result can be given for common bimodal form data, so that the technical problems of large error, high calculation complexity and great influence of an initial value on the fitting success rate and the stability are solved.

The invention relates to the technical field of laser devices, in particular to a Brillouin semiconductor laser device which comprises a gain chip, a Brillouin semiconductor laser device and a Brillouin semiconductor laser device, a Bragg grating; a microring resonator; the beam splitter is located between the micro-ring resonator and the Bragg grating; wherein the gain chip is used for generating spontaneous radiation light, the Bragg grating and the high-reflection film form a resonant cavity, the spontaneous radiation light is processed by the resonant cavity to form pump light, the pump light is injected into the micro-ring resonator through a second end of the Bragg grating, the micro-ring resonator generates a stimulated Brillouin scattering effect to generate Stokes light, and the Stokes light is transmitted to the high-reflection film. The micro-ring resonator carries out mode selection amplification on the Stokes light, ultra-narrow linewidth Brillouin laser is output from the first end of the micro-ring resonator, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset proportion. According to the Brillouin semiconductor laser, the integration level and the compactness of the Brillouin semiconductor laser are improved while it is guaranteed that the Brillouin semiconductor laser has excellent performance.

The invention discloses an integrated distributed optical fiber sensing extra-high voltage live working sling on-line monitoring system, and relates to the technical field of electric power safety monitoring, and the system comprises a multilayer flexible insulating sling body with a spiral staggered optical fiber embedding channel; the multimode optical fiber sensing unit is embedded in the channel and comprises a Bragg grating array and a Brillouin scattering optical fiber; the stress identification module is used for constructing a heat-force coupling response matrix and identifying a stress concentration area; the digital twin modeling module is used for constructing a local finite element sub-model and outputting a fatigue trend curve; the diagnosis feedback module is used for generating a sling risk level signal and realizing remote control linkage; the system can monitor the stress evolution and fatigue damage conditions of the sling structure in real time, has the advantages of high strain identification precision, accurate fatigue trend prediction, timely remote response and the like, and improves the safety and intelligent management level of extra-high voltage live working.

The invention discloses a multidimensional communication sensing system integrating an optical transmission network and BOTDR / DAS distributed sensing, and relates to the technical field of optical fiber communication and optical fiber sensing. The system comprises an OTN transmission subsystem, an optical fiber link and a BOTDR / DAS fusion sensing subsystem. Wherein the OTN transmission subsystem is used for realizing high-capacity data transmission through an optical fiber link; and the BOTDR / DAS fusion sensing subsystem is used for realizing strain, temperature and vibration distributed measurement of an optical fiber link through a Brillouin scattering and Rayleigh backscattering mechanism. According to the system, a double-self-heterodyne demodulation architecture and a reverse wavelength division multiplexing mechanism are adopted, cooperative demodulation and high-isolation transmission of BOTDR and DAS signals are achieved under the common-fiber condition, and high-speed communication and distributed temperature, strain and vibration synchronous monitoring within the 100 km range can be achieved. According to the method, a technical foundation can be laid for realizing physical layer intelligentization of the in-service power OTN.

The application provides an optical system and a monitoring method for monitoring stimulated Brillouin scattering effect. The optical system for monitoring stimulated Brillouin scattering effect firstly delivers a narrow linewidth seed source into a laser amplifier through a first optical device to amplify the narrow linewidth laser, and guides stimulated Brillouin scattering light generated by the laser amplifier to a back light monitoring module to detect the back light power and spectral components of the stimulated Brillouin scattering light in real time through the back light monitoring module, so as to realize the purpose of simultaneously and accurately measuring the stimulated Brillouin scattering light power and observing the laser components, and is more conducive to judging whether the stimulated Brillouin scattering effect occurs. Further, the optical system can adjust the light splitting ratio of the first optical device and the back light monitoring module to protect the narrow linewidth seed source and the spectrometer in the back light monitoring module from the damage of the back light to the greatest extent, and achieve the purpose of accurately judging the stimulated Brillouin scattering effect and protecting the system safety.

The application discloses a kind of photonic crystal fiber of bending resistance and with high Brillouin scattering gain, including surface layer, intermediate layer and core layer;Surface layer includes first oval air hole, and first oval air hole is arranged along the circumferential direction of photonic crystal fiber;Intermediate layer includes first part, second part, third part and fourth part, first part and third part are oppositely arranged, and respectively include a plurality of first circular air hole arranged into trapezoidal;Second part and fourth part are oppositely arranged, and respectively include a plurality of first circular air hole arranged into square;Core layer includes two symmetrically arranged second circular air hole, and the gap between each second circular air hole and first part and third part is filled with symmetrically arranged third circular air hole and third oval air hole.The application not only has good bending resistance, but also has higher Brillouin scattering gain.

The invention relates to the technical field of optical fiber cables, in particular to a railway signal cable with an optical fiber strain and humidity sensing function, which sequentially comprises a cable core, a heat insulation layer, an aluminum sheath, a lining layer, an armor layer and an outer sheath from inside to outside, and is characterized in that two DDS strain sensing optical cables are arranged in the cable core or between the aluminum sheath and the lining layer; a DHS humidity sensing optical cable is arranged in the cable core, the DDS strain sensing optical cable is utilized, Brillouin scattering is utilized, a BOTDR distributed optical fiber sensing instrument is adopted, and optical fiber deformation caused by cable construction non-standard digging breakage or crushing deformation, cable sheath and armor abrasion, mouse biting breakage, theft sawing breakage and the like is sensed; and secondly, through the DHS humidity sensing optical cable, the stress effect on the optical fiber caused by water swelling of the sensing water-blocking material is sensed, so that the conditions of cable stress, sheath water inflow or dampness can be continuously monitored in real time, early warning can be performed in advance, and hidden dangers of the cable can be eliminated, thereby eliminating insulation resistance faults and ensuring the safety and reliability of the railway signal cable in long-term use.

The invention discloses an in-operation OPGW icing tension monitoring method based on a micrometeorological temperature demodulation BOTDR. The method comprises the following steps: measuring through a Brillouin optical time domain reflectometer to obtain OPGW Brillouin frequency shift data; calibrating a Brillouin frequency shift temperature sensitivity coefficient and a Brillouin frequency shift tension sensitivity coefficient of the OPGW by using the data of the microclimate icing monitoring terminal; according to the Brillouin scattering principle, all Brillouin frequency shifts are converted into Brillouin equivalent temperatures; the external environment temperature of the OPGW is measured through the micro-meteorological icing monitoring terminal and is defined as temperature data of the micro-meteorological icing monitoring terminal; calculating a difference value between the Brillouin equivalent temperature and the temperature data of the microclimate icing monitoring terminal; and when the temperature difference value is greater than or equal to the temperature measurement precision of the Brillouin optical time domain reflectometer, the icing tension is calculated. According to the invention, the Brillouin frequency shift temperature sensitivity coefficient and the Brillouin frequency shift tension sensitivity coefficient can be directly calibrated on line, and the calibration result and the icing tension monitoring result are more accurate.

The invention relates to the technical field of lasers, in particular to a Brillouin hybrid integrated laser, which comprises a gain chip; the Bragg grating is connected with the first cavity surface; the first end of the micro-ring resonator is connected with the second cavity surface; the beam splitter is located between the micro-ring resonator and the gain chip; wherein the gain chip is used for generating spontaneous radiation light, the Bragg grating and the low-reflection film form a resonant cavity, the spontaneous radiation light is processed by the resonant cavity to form pump light, the pump light is injected into the micro-ring resonator through the second cavity surface, the micro-ring resonator generates a stimulated Brillouin scattering effect to generate Stokes light, and the Stokes light is transmitted to the Bragg grating and the low-reflection film. The micro-ring resonator performs mode selection amplification on the Stokes light and outputs ultra-narrow linewidth Brillouin laser, and the beam splitter outputs the ultra-narrow linewidth Brillouin laser according to a preset proportion. According to the Brillouin hybrid integrated laser, the integration level and the compactness of the Brillouin hybrid integrated laser are improved while it is guaranteed that the Brillouin hybrid integrated laser has excellent performance.

This invention discloses a wafer and chip defect detection system and method based on linear array Brillouin microscopy, belonging to the fields of optical precision measurement and wafer inspection. The system connects a Brillouin scattering detection module, a bright-field detection module, and a signal processing and feedback module; the signal processing and feedback module is connected to a displacement module; the signal processing and feedback module is also connected to an imaging and analysis module, transmitting single-shot linear beam measurement data to the imaging and analysis module; the displacement module is connected to the sample; and the Brillouin scattering detection module and bright-field detection module are connected to the sample to acquire sample information. This invention enables line-scan confocal measurement of the mechanical properties of wafers and non-transparent chips using the Brillouin scattering detection module, significantly improving the speed of Brillouin scattering detection; the combination of bright-field linear array detection and Brillouin scattering linear array detection allows for the simultaneous acquisition of geometric and mechanical stress defects in wafer and chip samples, broadening the range of defect detection parameters.

The invention discloses a marine mixed layer water environment parameter measurement method and system based on a stimulated Brillouin scattering acoustic grating, and relates to the field of marine water environment detection.The method comprises the steps that a dependency equation between stimulated Brillouin scattering frequency shift and water environment parameters is established, and a first dependency equation is obtained; the water body environment parameters comprise temperature and salinity; establishing a dependency relationship equation between the acoustic grating reflection spectrum center peak value frequency shift and the water body environment parameters to obtain a second dependency relationship equation; and calculating water body environment parameters based on the first dependency relationship and the second dependency relationship. According to the invention, complete distinguishing of marine mixed layer water body environment parameters can be realized, and the measurement precision is high.

The application discloses an SBS phase conjugation mirror capable of displaying a sound wave field in real time, and belongs to the technical field of nonlinear optics.The application comprises the following steps: pump light passes through a half-wave plate and a polarization beam splitter, passes through an optical isolator, changes a polarization state through a quarter-wave plate, is focused through a focusing lens, and then enters an SBS medium pool, stimulated Brillouin scattering occurs, a periodic density modulation is formed in the medium, and an equivalent acousto-optic grating structure is generated.Through introducing an independent probe light beam, the probe light enters the SBS medium pool at an incident angle satisfying the Bragg diffraction condition, and the probe light will be diffracted on the acousto-optic grating formed by the sound wave field.The intensity of the diffracted light changes with the intensity of the sound wave field, so that the real-time measurement of the sound wave field waveform and the life parameter in the SBS process can be realized by detecting the change of the diffracted light intensity with time.

Suppressing Stimulated Brillouin Scattering (SBS) in an Optical Amplifier system comprising: an optical fan out which splits a coherent optical beam into a set of multiple optical beams, a set of opti

A kind of distributed multi-parameter sensing system based on multi-core optical fiber, including laser, laser light source is sent to the signal generator input trigger pulse drive respectively with the signal input end of phase-sensitive optical time domain reflectometer based on Rayleigh scattering and its demodulation device, Raman optical time domain reflectometer based on Raman scattering and its demodulation device, Brillouin optical time domain reflectometer based on Brillouin scattering and its demodulation device are connected, the signal output end of phase-sensitive optical time domain reflectometer and its demodulation device, Raman optical time domain reflectometer and its demodulation device, Brillouin optical time domain reflectometer and its demodulation device is connected with the signal input end of multi-core optical fiber through multi-core optical fiber fan-in fan-out module;The present application utilizes the principle of space division multiplexing, each fiber core in optical cable as separate sensing channel carries out measurement and signal transmission;Multi-core optical fiber fuses three kinds of distributed optical fiber sensing systems together, realizes in-situ measurement and mutual compensation decoupling of temperature, strain and vibration, improves the measurement precision of sensing system.

The purpose of the present invention is to provide a Brillouin scattering measuring device capable of compensating for fluctuations in a frequency component of broadband probe light and performing highly accurate measurement.　A Brillouin scattering measuring device according to the present invention: acquires broadband probe light that includes Brillouin scattering light and broadband probe light that does not include Brillouin scattering light by using two broadband pulsed light beams having the same optical characteristics; compensates for fluctuations in a frequency component of the broadband probe light that includes Brillouin scattering light on the basis of the broadband probe light that does not include Brillouin scattering light; and performs Lorentzian fitting on a signal obtained by dividing the broadband probe light that includes Brillouin scattering light by the broadband probe light that does not include Brillouin scattering light to determine a peak position in a BGS.

The application discloses a kind of multi-channel wide spectrum scattered light energy simultaneous measurement device and method, wherein multi-channel wide spectrum scattered light energy simultaneous measurement device mainly includes target chamber, spectrometer, gate camera and multiple scattered light imaging light paths.The present multi-channel wide spectrum scattered light energy simultaneous measurement device and method are used, by setting multiple scattered light imaging light paths, realize multi-channel measurement capability, can accurately give the energy of different wavelengths and total energy, realize the simultaneous measurement of stimulated brillouin scattering and stimulated raman scattering scattered light, provide more reliable diagnostic techniques for the scattered light generated by laser target shooting;At the same time, the present measurement method greatly reduces the use of energy probe, not only saves cost, but also improves diagnostic efficiency;And, the present measurement method can be used not only for high-energy scattered light measurement, but also for other light source intensity analysis and comparison.

The invention discloses an all-optical microwave oscillator based on a non-polarized radial mode LN-PM birefringence effect, which is used for solving the technical problem that an electronic bottleneck of high frequency and low stability is difficult to break through due to the fact that additional noise is extremely easy to generate due to introduction of an electric signal in a traditional photoelectric oscillator, and belongs to the technical field of optical fiber communication and microwave photonics. The birefringence effect of LN-PM is introduced into the microwave photonic oscillator based on forward Brillouin scattering, the gain and loss coefficient of forward Brillouin are controlled by adjusting a polarization controller, and when the gain coefficient is equal to the loss coefficient and greater than a coupling coefficient, the space time is symmetrically broken to obtain single longitudinal mode microwave photon output. Compared with the prior art, the self-excited pumping source is adopted, electric signal modulation is not needed, a single-frequency microwave photon signal which is high in frequency stability, low in phase noise and high in side-mode rejection ratio can be generated, and the system has the advantages of being simple in structure and higher in adaptability and reliability.

The invention provides a stimulated Brillouin scattering suppression device and method of an optical fiber amplification system, and the device comprises a seed source, a signal generator, a radio frequency amplifier, a signal modulator and a spectrum filter. And performing power amplification on the LFM radio-frequency signal output by the signal generator by using a radio-frequency amplifier so as to drive the signal modulator to modulate the seed laser and generate a modulation spectrum containing a carrier and a plurality of sidebands, and finally screening out a single target sideband through a spectrum filter to obtain a sweep-frequency light source. Effective suppression of stimulated Brillouin scattering is realized in an optical fiber amplification system. According to the invention, high modulation voltage can be prevented from being applied, and the voltage-withstanding range of an existing commercial signal modulator is adapted; meanwhile, the modulation period range is large and controllable, the short modulation period can meet the short optical fiber scene requirement of the optical fiber amplification system, and the SBS suppression effect of the optical fiber amplification system is effectively improved.

The invention belongs to the field of distributed optical fiber sensing, particularly relates to a highway infrastructure safety early warning device and method based on high-dimensional chaotic optical fiber sensing, and aims to realize multi-parameter synchronous accurate monitoring of highway infrastructures in a complex environment. The device comprises a light source, a light path distribution modulation module, a signal detection and separation module and a data processing module which are connected in sequence, and the light path distribution modulation module is further connected with a to-be-detected optical fiber group. The light source module generates high-dimensional wavelength tunable chaotic laser, the light path distribution modulation module divides the high-dimensional wavelength tunable chaotic laser into a detection path and a pumping path, modulates the high-dimensional wavelength tunable chaotic laser and transmits the modulated high-dimensional wavelength tunable chaotic laser to a selected to-be-detected optical fiber, and meanwhile, receives a backscattering signal and transmits the backscattering signal to the signal detection and separation module. The module separates Raman and Brillouin scattering signals and converts the signals into electric signals, the data processing module processes the electric signals, and intelligent recognition and early warning of highway infrastructure disasters are achieved.

The invention provides a hydraulic steel gate stress detection method, and relates to the technical field of hydraulic engineering safety monitoring, strain and stress detection is realized through a distributed optical fiber sensing unit based on Brillouin scattering, and compared with a traditional point sensor, the hydraulic steel gate stress detection method has the advantages of being small in monitoring blind area and beneficial to realizing global detection. The distributed optical fiber sensing unit is combined with the acoustic phased array excitation unit, so that the false alarm probability is reduced. And when the verification result of the acoustic phased array excitation unit is the microcrack, the found initial damage can be actively intervened in time, and malignant development of the microcrack is avoided.