333 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 discloses a slope stability evaluation and landslide early warning system and method based on strain monitoring, and relates to the technical field of geotechnical engineering safety monitoring, in the slope stability evaluation system, strain monitoring optical cables are arranged in a plurality of drill holes formed in a slope in a penetrating mode and are fully coupled with slope soil; laser is emitted to the strain monitoring optical cable through a Brillouin optical time domain reflectometer, and a Brillouin scattering light signal is received from the strain monitoring optical cable; brillouin frequency shift is determined according to the Brillouin scattered light signals, then transverse shear force is determined according to the Brillouin frequency shift, the slope stability coefficient of the slope is calculated according to the change of the transverse shear force, and whether landslide is likely to happen or not is further judged in combination with soil humidity measured by the humidity monitoring optical cable, and early warning is conducted in time. Compared with an existing slope monitoring technology, the slope monitoring system has the advantages of being high in precision, wide in monitoring range, resistant to electromagnetic interference, resistant to corrosion and the like, and real-time effective monitoring of different deformation stages of a slope can be achieved.

The invention relates to the field of highway safety monitoring, and discloses a highway subgrade safety monitoring system and a risk identification method, and the system comprises a distributed optical fiber sensing subsystem and a video image capturing equipment subsystem which are respectively connected with a rear-end server; the distributed optical fiber sensing subsystem comprises distributed Rayleigh scattering optical fibers and / or distributed Brillouin scattering optical fibers which are arranged on a highway subgrade according to risk levels and is used for collecting dynamic information related to the highway subgrade, and the dynamic information represents environment and state changes of the highway subgrade; the video image capture device subsystem comprises a plurality of AI video image capture devices; and after receiving the dynamic information, the back-end server inputs the dynamic information into a preset calculation model to obtain a deformation index parameter output by the preset calculation model, determines a response level of the AI video image capture device according to the deformation index parameter, and configures an operation parameter of the AI video image capture device based on the response level. According to the system, real-time, accurate and comprehensive monitoring of a road is realized through cooperation of the distributed optical fiber, the AI video image capturing equipment and the back-end server.

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 provides a high-concentration ytterbium-doped double-clad silicate optical fiber single-frequency amplifier which comprises a single-frequency laser seed source, a double-clad optical fiber pre-amplifier and a high-concentration ytterbium-doped double-clad silicate optical fiber main amplifier which are connected in sequence. The single-mode optical fiber pre-amplifier is used for primarily amplifying the single-frequency laser; the double-clad optical fiber pre-amplifier is used for further amplifying the optical signal output from the single-mode pre-amplifier; and the high-concentration ytterbium-doped double-clad silicate optical fiber main amplifier is used for performing high-power amplification on the signal light amplified by the double-clad optical fiber pre-amplifier and outputting specific high-power narrow-linewidth single-frequency laser. Single-frequency laser seed source low-noise coefficient pre-amplification is achieved through a front multi-stage pre-amplification system, a high-concentration ytterbium-doped double-clad silicate optical fiber is adopted in a final main amplifier, the length of a needed active optical fiber is shortened through provided high gain, the stimulated Brillouin scattering effect is restrained, and the optical fiber is high in gain and high in power consumption. And the output power of the single-frequency narrow-linewidth optical fiber amplifier is improved.

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.

A 2-micron large-energy solid two-way amplifier based on a single-frequency pulse optical fiber preceding stage can make full use of the small signal amplification capacity of optical fiber laser and the energy extraction capacity of solid laser, and meanwhile the problem that energy is difficult to improve due to the stimulated Brillouin scattering effect in an optical fiber is solved. And high-stability, high-repetition-frequency and large-energy single-frequency pulse laser output can be realized. The all-fiber cascade amplifier comprises an all-fiber cascade amplifier and a solid two-way amplifier, according to the all-fiber cascade amplifier, a continuous narrow-linewidth fiber laser is adopted as a seed source, continuous light is modulated into pulse light through an acousto-optic modulator, and the waveform, the pulse width and the repetition frequency of output pulse laser are adjusted; the modulated pulse light adopts a main oscillation power amplification structure and is preliminarily amplified by a polarization maintaining optical fiber amplifier; the solid-state amplifier adopts a two-way amplification structure, and further high-efficiency amplification is realized through solid-state two-way amplification. The whole laser system is compact in structure, stable, adjustable in parameter and capable of meeting application requirements of different scenes.

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 discloses a single-ended BOTDA (Brillouin Optical Time Domain Analysis) multi-parameter simultaneous measurement method and a single-ended BOTDA multi-parameter simultaneous measurement device, and relates to the technical field of measurement. Wherein backward Rayleigh scattering light generated by continuous light in different modes in the few-mode optical fiber is used as detection light, sensing pulse light in different modes is used as pump light, and the detection light and the pump light in each mode generate intramode and intermode stimulated Brillouin scattering effect; then a photon lantern is used as a demultiplexer to extract detection light signals of each linear polarization mode, a photoelectric detector is used for detection, and finally temperature, strain and bending values are analyzed according to different characteristics of Brillouin frequency shift of each mode and corresponding coefficients of each physical quantity. According to the single-ended BOTDA multi-parameter simultaneous measurement method and device, the structure is simple, application is convenient, detection can still be carried out when optical fibers are broken, and multi-parameter simultaneous measurement with the high signal-to-noise ratio can be achieved.

The invention discloses a passive optical fiber stimulated Brillouin scattering effect threshold value self-adaptive testing device, and relates to the field of narrow linewidth optical fiber lasers, the device comprises a laser, a monitoring module and a driving power supply, the driving power supply is connected with the laser and the monitoring module, the laser is connected with the monitoring module and a passive optical fiber, and the monitoring module is connected with the passive optical fiber. The laser device generates signal laser and transmits the signal laser to the passive optical fiber so that the passive optical fiber can reflect reverse return light to the monitoring module, the driving power source drives the laser device and improves the output power of the laser device to preset first power, and the monitoring module monitors the return light power of the reverse return light and sends the signal laser to the passive optical fiber when the return light power is larger than preset second power. A stimulated Brillouin scattering threshold value is determined according to the light return power, and when the stimulated Brillouin scattering threshold value is larger than preset first power, the monitoring module judges that the passive optical fiber meets the stimulated Brillouin scattering threshold value requirement. Compared with manual testing, the method has the advantage that the detection efficiency of the SBS threshold value of the passive optical fiber is improved.

Systems and methods are provided for analyzing a biomechanical property of a medium using stimulated Brillouin scattering microscopy. The method can include a first step of applying a probe beam and pulsed pump beam to a target section of the medium, wherein the pump beam interacts with the probe beam to generate at least one acoustic wave in the medium and at least one Brillouin signal is produced as a result of the generated acoustic wave. The method can also include a second step of receiving the produced Brillouin signal and a third step of determining, using a processor and the Brillouin signal, information associated with at least one biomechanical property of the target section.

The invention relates to the technical field of signal processing, in particular to a parameter extraction method and device based on a Brillouin scattering spectrum, equipment and a medium. The method comprises the following steps: acquiring to-be-processed Brillouin spectral data, and determining peak data in the Brillouin spectral data; according to the peak value data, a bimodal coefficient corresponding to the Brillouin spectrum is calculated through a preset bimodal feature algorithm; determining a target fitting algorithm for processing the Brillouin spectrum data based on the double-peak coefficient; and reconstructing the Brillouin spectrum data by using the target fitting algorithm, and extracting target parameters from the reconstructed Brillouin spectrum data. By adopting the method, the stability of single-peak and double-peak discrimination processing can be improved, and the accuracy of an analysis result is improved.

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.

The invention relates to the technical field of mining, and provides an early warning method and system for coal and gas outburst of a driving face based on stress monitoring. According to the method, distributed strain optical fibers are laid in a coal body in front of a tunneling working face through a staggered drilling field, continuous and real-time monitoring of the ground stress of the coal body is achieved by means of the Brillouin scattering effect of the optical fibers, and a series of problems of locality, large errors, discontinuity, large work amount, occupied operation time and space and the like of stress monitoring of the tunneling working face are solved; noise elimination is carried out through ensemble empirical mode decomposition, the quality of coal body crustal stress data is improved, the range of a coal body crustal stress concentration area is rapidly determined, and the internal stress peak value and the stress change rate of the stress concentration area are tracked and compared with critical values. The coal and gas outburst early warning method is suitable for coal and gas outburst prevention and control of the driving face of the coal and gas outburst mine.

An apparatus for digitizing an optical signal comprises: an optical detector to detect an optical signal and to generate an electric signal corresponding to the optical signal; an envelope curve detector to determine the amplitude of the electric signal or a modified electric signal resulting from the electric signal, and to supply an amplitude signal corresponding to the amplitude; an analog to digital converter to digitize the amplitude signal and to supply a corresponding digitized amplitude signal; and a variable voltage source to calibrate the envelope curve detector.

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 a two-dimensional measurement method for the temperature of a combustion field, which comprises the following steps: tuning laser frequency to be stabilized in the center of an iodine molecule absorption line, outputting a narrow-linewidth single-longitudinal-mode continuous light beam by a laser, dividing the light beam into two light beams by a spectroscope, enabling one light beam to pass through a reference light path and be used for acquiring an instrument function of a VIPA-based spectrograph, and enabling the other light beam to pass through a reference light path; the other beam of light is incident into a combustion field as exciting light and interacts with gas in the combustion field to generate a scattering signal, the light receiving system collects and filters the scattering signal to obtain filtered Rayleigh-Brillouin scattering (FRBS), and the filtered Rayleigh-Brillouin scattering (FRBS) is transmitted to the spectrograph and the CCD through the optical fiber for spectral resolution and signal acquisition. The scanning system completes two-dimensional profile scanning of a combustion field, retrieves the temperature of an acquired FRBS spectral line through an FRBS theoretical model, and achieves two-position measurement of the temperature of the combustion field. The method can be provided for retrieving the gas temperature based on FRBS in a high-temperature environment containing strong mie scattering or strong background light, can adapt to different environments and requirements, and provides higher flexibility.

To correct a measurement error of BFS by performing calculation of BFS on the basis of an extinction ratio of optical pulses.SOLUTION: An optical fiber sensor comprises: a light source section for generating probe light that is an optical pulse train; an optical coupler for branching probe light into two; an interference signal acquisition section for generating an interference signal by self-delay type heterodyne interference after rear Brillouin scattered light generated by an optical fiber measured by one probe light branched into two by an optical coupler is inputted; an extinction ratio measuring instrument for measuring an extinction ratio of the other probe light branched into two by the optical coupler; and signal processing means. The signal processing means includes: BFS calculation means for calculating a Brillouin frequency shift amount as a BFS measurement value from an interference signal; and extinction ratio correction means for correcting a BFS measurement value and obtaining a true BFS value on the basis of an extinction ratio measured by the extinction ratio measuring instrument.SELECTED DRAWING: Figure 1

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 high-spatial-resolution multi-parameter fusion type distributed optical fiber sensing system, and the system comprises a light source module which is used for providing a light source for the whole sensing system, and generating two branches of laser output; the pulse generation module is used for generating pulsed light by using the first light branch; the first optical fiber circulator is used for transmitting the pulsed light and scattered light returned from the sensing optical fiber; the scattered light separation module is used for receiving the scattered light returned by the first optical fiber circulator and separating the scattered light into Brillouin scattered light and Rayleigh scattered light; the local oscillation light generation module is used for generating BOTDR local oscillation light and # imgabs0 # local oscillation light by utilizing the second optical branch; the coherent detection module is used for carrying out coherent detection on Brillouin scattered light and BOTDR local oscillation light and carrying out coherent detection on Rayleigh scattered light and # imgabs1 # local oscillation light so as to obtain corresponding electric signals; and the data acquisition device is used for acquiring the corresponding electric signal. The spatial resolution index of the method reaches 1m or even better.