264 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 relates to the technical field of optical fiber communication, in particular to a digital twin model parameter updating method applied to an optical cable. The method comprises the following steps: collecting optical fiber laying data; performing laying structure division based on the optical fiber laying data to obtain flat structure optical fiber data and layer-stranded optical fiber data; evaluating the tensile strength of the optical cable based on flat structure optical fiber data; detecting the optical signal transmission intensity of the flat-structure optical fiber data based on the tensile property of the optical cable; performing intelligent loss compensation on the flat structure optical fiber data according to the optical signal transmission intensity to obtain signal compensation data; calculating the distribution uniformity based on the layer-stranded optical fiber data; determining optical fiber dislocation based on the distribution uniformity to obtain optical fiber dislocation data; and performing optical fiber Brillouin scattering detection based on the optical fiber dislocation data to obtain Brillouin scattering data. The accuracy and real-time performance of optical cable performance evaluation are improved based on the optical fiber communication technology, and therefore the stability and reliability of optical cable signal transmission are remarkably 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 discloses an optical cable icing galloping online monitoring system based on a BOTDR, and belongs to the technical field of distributed optical fiber sensing. The system comprises an optical module, a signal processing module and a data processing module, the optical module is used for generating a detection light signal and interacting with a sensing optical fiber to obtain a Brillouin scattering signal, and then the Brillouin scattering signal is converted into an electric signal; the signal processing module is used for performing frequency down-conversion, signal filtering and digital acquisition on the electric signal to obtain multiple groups of Brillouin scattering signal data; the data processing module is used for processing the multiple groups of Brillouin scattering signal data and extracting a Brillouin frequency shift center frequency; temperature and strain distribution along the optical cable is obtained according to the frequency shift, and temperature and strain states are transmitted to a QT upper computer through PCIE for real-time display. According to the invention, high-precision and long-distance optical cable icing galloping monitoring can be realized, reliable early warning and safety guarantee are provided, and technical support is provided for maintenance and management of an electric power system.

The invention discloses an edge calculation optimization and compression algorithm based on distributed optical fiber sensing data, and the algorithm achieves the full-section continuous monitoring of an embankment through the layering burying of a distributed optical fiber network along the axis of the embankment, and eliminates the blind area of a conventional point sensor. Strain data and temperature data are analyzed by using Brillouin scattering and Raman scattering, time sequence characteristics are analyzed through an LSTM neural network, and piping and crack hidden dangers are identified. External environment parameters such as water level and rainfall are fused to construct a multiple regression model, and the seepage risk level is evaluated. Through combination of BIM three-dimensional modeling and a seepage simulation algorithm, hidden dangers are accurately positioned, and spatial distribution of the hidden dangers is visualized. Based on edge calculation optimization, a data compression technology is adopted to reduce transmission requirements, a self-repairing material injection and high-pressure plugging scheme is triggered through a grading early warning system, closed-loop management from monitoring to repairing is formed, the real-time performance and accuracy of hidden danger recognition are improved, and efficient and reliable monitoring support is provided for dike engineering.

The invention discloses an optical frequency comb generation method and device based on Brillouin scattering and an electro-optical modulator, and belongs to the field of photoelectric measurement. The method comprises the steps that a first laser and a second laser are used for generating pump light and seed light respectively, multi-wavelength pump light is generated through a cascade electro-optical modulator, the pump light and the seed light are emitted into a Sagnac loop, an optical frequency comb is output through the forward Brillouin scattering effect of an optical fiber and the electro-optical modulator, and the seed light and the pump light are output. The polarization controller is adjusted to optimize polarization state matching of the pump light and the seed light, so that the Brillouin scattering effect reaches the maximum value. The device is composed of a laser, an electro-optical modulator, a signal generator, an optical amplifier, an optical isolator, an optical coupler, a polarization controller and an optical fiber. The optical fiber forward Brillouin scattering effect and the electro-optical modulator are combined, the optical frequency comb giving consideration to the wide frequency spectrum and the narrow interval is generated, meanwhile, the comb tooth interval of the optical frequency comb can be accurately controlled by independently adjusting the frequency of the signal generator, and accurate measurement of signals or objects is achieved.

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 provides a signal receiving device, a signal transmitting device and an optical fiber sensing device, relates to the technical field of optical fiber sensing, and is used for solving the problems that the requirement for equipment is high when an existing optical fiber sensing device detects Rayleigh scattering and Brillouin scattering at the same time and the like. The signal receiving device comprises a coherent receiver, a radio frequency analog-to-digital conversion unit and a frequency band calculation unit, the coherent receiver is used for obtaining four electric signals with orthogonal phases according to the local oscillation light and the signal light, and the radio frequency analog-to-digital conversion unit converts the four electric signals to obtain two digital signals in a first polarization state and two digital signals in a second polarization state; the frequency band calculation unit is used for calculating the frequency spectrum of the signal light according to the two paths of digital signals of the first polarization state of the signal light and the two paths of digital signals of the second polarization state of the signal light, and the frequency spectrum comprises a phi OTDR signal located at the positive frequency and a BOTDR signal located at the negative frequency.

The invention belongs to the technical field of road engineering detection, and discloses a geological radar and distributed optical fiber roadbed compaction detection method and device, and the method comprises the steps: obtaining a dielectric constant profile detected by a radar and the initial Brillouin scattering light frequency offset of optical fiber strain; establishing an initial reference state including optical fiber strain distribution and a radar dielectric constant profile; comparing the Brillouin scattering light frequency offset and the radar dielectric constant profile image which are acquired in real time with an initial reference state, determining a strain gradient abrupt change region, and correcting a preset optical fiber temperature drift compensation model by using a radar scanning result; and performing temperature drift component removal on the Brillouin scattering light frequency offset obtained in real time to obtain pure strain frequency shift data, calculating according to the frequency shift data to obtain accumulative settlement, and generating a roadbed compaction effect detection result. Continuous longitudinal strain monitoring is provided through the geological radar and the sensing optical fiber, and an abnormal section is accurately positioned.

The invention provides a BOTDR (Brillouin optical time domain reflectometry) system fusing Stokes-anti-Stokes light and a demodulation method, and belongs to the technical field of Brillouin distributed optical fiber sensing. The narrow linewidth laser is used for generating continuous optical signals; the input end of the coupler is connected with the laser, and the output end is connected with the pulse light branch and the local oscillator light branch. The pulsed light branch comprises a semiconductor optical amplifier, a random scrambler, a first erbium-doped optical fiber amplifier and a circulator which are connected in sequence; the local oscillator light branch comprises an electro-optical modulator, and the electro-optical modulator regulates and controls sideband frequency through a microwave module; the second erbium-doped optical fiber amplifier is used for extracting the Stokes light and the anti-Stokes light; the single-mode coupler mixes the double-sideband local oscillator light with the anti-Stokes light and the Stokes light; and the electrical beat frequency signals are acquired, filtered and enveloped and demodulated through an acquisition card. The detection capability of the Brillouin scattering signal is enhanced, the system structure is simplified, and the hardware cost and the maintenance difficulty are reduced.

Disclosed is a linear array scanning Brillouin scattering elastic imaging device. In the device, a signal generating system consists of a narrow linewidth continuous wave laser, a half-wave plate, a beam expander, a Y-direction scanning galvanometer, a microlens array, a pinhole array filter, a first plano-convex lens, a polarization beam splitter, a quarter-wave plate and a microscope objective. A signal receiving system consists of a microscope objective, a quarter-wave plate, a polarization beam splitter and an eight-channel optical collimator array. Each channel of an eight-channel spectrometer consists of an optical collimator, a convex lens, a scanning Fabry-Perot interferometer, a photomultiplier tube and an eight-channel photon collection card.

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 provides an optical system and a monitoring method for monitoring a stimulated Brillouin scattering effect, and the optical system for monitoring the stimulated Brillouin scattering effect comprises the steps: firstly, conveying a narrow-linewidth seed source into a laser amplifier through a first optical device, and carrying out the narrow-linewidth laser amplification; and the stimulated Brillouin scattering light generated by the laser amplifier is guided out to the return light monitoring module, so that the return light power and the spectral component of the stimulated Brillouin scattering light are detected in real time through the return light monitoring module, and the purposes of simultaneously and accurately measuring the power of the stimulated Brillouin scattering light and observing the laser component are achieved. Whether the stimulated Brillouin scattering effect occurs or not can be judged more easily; furthermore, according to the optical system, the narrow-linewidth seed source and a spectrograph in the return light monitoring module can be protected from being damaged by return light to the maximum extent by adjusting the light splitting proportion of the first optical device and the return light monitoring module, and the purposes of accurately judging the stimulated Brillouin scattering effect and protecting system safety are achieved.

The invention discloses an OPGW optical cable lightning stroke positioning monitoring system and monitoring method based on distributed optical fiber sensing. Comprising a DFB laser, a first optical coupler, an acoustic optical modulator, a pulse signal generator, a scrambler, a first EDFA optical amplifier, a first optical isolator, an optical circulator, an FBG filter, an OPGW sensing optical cable, an electro-optical modulator, a microwave signal generator, a polarization regulator, a second EDFA optical amplifier, a second optical isolator, a second optical coupler and a variable optical attenuator which are connected in sequence. A third optical coupler, a balance detector, a low-frequency amplifier and a data processing module. The system can quickly and accurately position the lightning stroke position of the OPGW optical cable by measuring the Brillouin scattering frequency shift and the vibration state of the scattering signal.

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.

Various example embodiments supporting optical communications in an optical communication system may be configured to support joint stimulated Brillouin scattering (SBS) suppression and polarization tracking for a set of orthogonal polarization optical channels in an intensity modulated / direct detection (IM / DD) passive optical network (PON). Various example embodiments may be configured to support joint SBS suppression and polarization tracking for a set of orthogonal polarization optical channels based on a set of frequency tones (e.g., using a single frequency tone per optical channel in the set of orthogonal polarization optical channels, respectively) such that SBS suppression is supported for transmissions from the transmitter (e.g., based on application of the frequency tones to the optical channels) and polarization tracking is supported at the receiver (e.g., based on use of one or more of the frequency tones of the optical channels in the set of orthogonal polarization optical channels for polarization tracking).

The invention provides a laser system for suppressing stimulated Brillouin scattering, and the system comprises a signal generation unit, a radio frequency amplification unit and a phase modulator, the signal generation unit is used for transmitting at least two radio frequency signals, and the at least two radio frequency signals comprise a wide bandwidth signal and a high-frequency sinusoidal signal; the radio frequency amplification unit is used for amplifying the synthesized at least two radio frequency signals and loading the amplified radio frequency signals to the phase modulators, or the radio frequency amplification unit is used for amplifying each radio frequency signal in the at least two radio frequency signals and loading each amplified radio frequency signal to the multiple cascaded phase modulators; the phase modulator is used for performing phase modulation on the laser signal emitted by the seed source through the loaded radio frequency signal and sending the modulated signal to the optical fiber amplification system; according to the invention, the generation of SBS pulses can be effectively inhibited, and the output power and stability of the laser are improved.

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 belongs to the technical field of microwave photons and optical communication, particularly relates to a tunable narrow-linewidth microwave photonic oscillator based on forward Brillouin scattering, and solves the technical problems that an existing microwave photon generation method is complex in structure and poor in tunability, and linewidth cannot meet requirements. The erbium-doped optical fiber amplifier is connected to a first optical fiber coupler through a filter, two output ends of the first optical fiber coupler are respectively connected to a third optical fiber coupler and a second optical fiber coupler, and two output ends of the second optical fiber coupler are respectively connected to a spectrograph and are sequentially connected with a photoelectric detector and a spectrum analyzer; two output ends of the third optical fiber coupler are respectively connected to an input end c of a fourth optical fiber coupler through a first polarization controller and a first single-mode optical fiber and connected to an input end b of the fourth optical fiber coupler through a second polarization controller and a second single-mode optical fiber in sequence; and the fourth optical fiber coupler is connected to an erbium-doped optical fiber amplifier through a third polarization controller.

An object of the present disclosure is to provide a few-mode fiber testing method and a few-mode fiber testing device capable of acquiring a loss and inter-mode crosstalk for each mode at a connection point of a few-mode fiber by measurement only from one end of FUT. The few-mode fiber testing method according to the present disclosure includes receiving a test light pulse in a basic mode from one end of an optical fiber under test that is connected in series with few-mode fibers of the same type, measuring an intensity distribution relating to a distance from the one end of backward Brillouin scattering light generated by receiving a test light pulse, obtaining a transmittance of the backward Brillouin scattering light at a connection point of the optical fiber under test from the measured intensity distribution, and calculating a connection loss of the basic mode from the transmittance, calculating a ratio of an axial deviation amount to a mode field radius of the optical fiber under test at the connection point from the calculated connection loss, and calculating a connection loss of a higher-order mode and inter-mode crosstalk between different modes from the calculated ratio.

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.