210 results about "Rayleigh scattering" patented technology

The invention provides a sensing system fusing optical fiber vibration and acoustic emission, a monitoring method and a device, and relates to the technical field of optical fiber sensing. The device comprises a light source module, a sensing optical fiber, a detection module and a controller, the light source module is used for respectively emitting modulation pulse light for vibration monitoring and continuous wave laser for acoustic emission monitoring; the sensing optical fiber is arranged along a monitored structure or area, and at least one optical fiber acoustic emission sensing head is connected to the optical fiber in series. The detection module collects Rayleigh scattering light and beat frequency signals at all positions in the sensing optical fiber through a circulator and a coherent light receiver, and optical signals are converted into electric signals; wherein the electric signals comprise vibration electric signals and acoustic emission electric signals; the signal processing unit carries out phase demodulation and envelope analysis processing on the collected vibration electric signals and acoustic emission electric signals so as to obtain vibration waveforms and acoustic emission event space-time information along all points of the optical fiber. According to the invention, a monitoring task fusing vibration and acoustic emission can be accurately completed.

The invention relates to the technical field of bionic navigation orientation and positioning, in particular to a carrier course angle measuring method based on polarized light imaging in a non-Rayleigh atmosphere. Comprising the steps of real-time sky polarized light imaging, atmospheric polarization mode resolving based on Mueller matrix imaging, non-Rayleigh polarization information interference removal, polarization orientation resolving based on Rayleigh scattering, space projection conversion and sun position information resolving. Alignment information of the sun in a carrier coordinate system is obtained by utilizing a Rayleigh scattering model and actual sky polarization imaging, and then a carrier course angle is obtained according to the orientation of the sun in a local geographic coordinate system, so that an orientation function is realized; meanwhile, the error influence caused by image registration and time-sharing rotation measurement of the multi-view-field polarization detector and the interference of environmental factors on a single point are avoided, the method can adapt to sunny and cloudy weather, is also applicable to cloudy and other non-Rayleigh weather, and is wide in application range.

The invention discloses a distributed OFDR sensing signal demodulation method and system based on local ridge line tracking, relates to the technical field of optical fiber sensing, and is used for solving the problem that a traditional cross-correlation algorithm is difficult to consider robustness and real-time performance at the same time. The method comprises the following steps: respectively processing a reference beat frequency signal of a sensing optical fiber to be measured in a strain-free state and a measurement beat frequency signal of the sensing optical fiber to be measured in a strain state to obtain a reference complex Rayleigh scattering signal and a measurement complex Rayleigh scattering signal containing a plurality of sensing positions along the optical fiber; calculating a cross-correlation function based on the two signals; stacking the cross-correlation functions corresponding to all sensing positions along a distance domain, and constructing a two-dimensional cross-correlation thermodynamic diagram matrix; performing filtering processing and weighting processing on the two-dimensional cross-correlation thermodynamic diagram matrix to obtain an optimal frequency drift distance; and demodulating based on the optimal frequency drift amount to obtain strain distributed along the to-be-measured sensing optical fiber. According to the invention, high-robustness and rapid demodulation of the signal in an application scene with extremely high real-time requirement can be realized.

An optical frequency domain reflectometer with environmental disturbance resistance and large strain measurement capability belongs to the field of distributed optical fiber sensing and comprises an opposite sweep frequency light frequency modulation continuous wave signal generation module, a light splitting device, a modulation device, a circulator, a polarization controller, an optical coupling device, a photoelectric conversion module and a data acquisition and processing module. An optical signal generated by an opposite sweep frequency light frequency modulation continuous wave signal generation module is divided into probe light and local oscillation light through a light splitting device, the probe light is modulated through a modulation device and sent to an optical fiber through a circulator, and a Rayleigh back scattering light signal generated by the optical fiber and the local oscillation light interfere in an optical coupling device to obtain interference light; the photoelectric conversion module mixes beat frequency signals of interference light, and the data acquisition and processing module analyzes and processes the beat frequency signals. According to the invention, the position information of the Rayleigh backscattering point is marked by using the modulated probe light, the Rayleigh scattering signal at the corresponding position is restored, crosstalk between channels is inhibited, and high-precision measurement in a large dynamic range and resistant to environmental disturbance is realized.

The invention relates to a damaged point monitoring system and method for a hollow-core optical fiber, computer equipment, a medium and a product, and relates to the technical field of telecommunication operation and maintenance. The system comprises a sensing sending module and a sensing receiving module, wherein the sensing transmitting module is used for transmitting a target optical pulse coding signal corresponding to a current monitoring mode to a to-be-detected hollow-core optical fiber; the monitoring mode comprises an on-line monitoring mode and an off-line monitoring mode, and the wavelength bands of the target optical pulse coded signals corresponding to the on-line monitoring mode and the off-line monitoring mode are different; and the sensing receiving module is used for receiving the backward Rayleigh scattering light reflected by the to-be-detected hollow-core optical fiber and positioning a damaged point of the to-be-detected hollow-core optical fiber according to the backward Rayleigh scattering light and the layout path information of the to-be-detected hollow-core optical fiber. The system can accurately position the damaged point of the hollow-core optical fiber.

The invention provides a power distribution communication network optical cable fault prediction method and system based on machine learning. The method comprises the following steps: collecting Rayleigh scattering signals of a plurality of monitoring points along an optical cable; performing unsupervised learning on the optical cable adaptive reconstruction model, and calculating a reconstruction error matrix and an abnormal cumulative metric; constructing an optical cable network diagram, calculating a fault propagation probability matrix, predicting a future optical cable health index, and obtaining a future health index matrix; establishing an environment influence matrix, and adopting an optical cable environment adaptive filtering model; and based on the health index and the fault confidence coefficient matrix after filtering optimization, optical cable maintenance priority scores are calculated and sorted, and a self-adaptive inspection and maintenance strategy is formulated. According to the invention, high-precision monitoring, fault propagation prediction and environmental adaptability optimization of the health state of the optical cable are realized, and the intelligent level of operation and maintenance of the optical cable is improved.

The invention belongs to the technical field of distributed optical fiber sensing, and relates to a phase-frequency noise suppression optical frequency domain reflection measurement method and system without an auxiliary interferometer. The measurement method comprises the following steps: acquiring positive and negative double-sideband sweep-frequency light with the same sweep-frequency range and opposite sweep-frequency directions; dividing the positive and negative double-sideband sweep frequency light into double-sideband detection light and double-sideband local oscillation light according to a preset proportion; configuring a pseudo-random noise code, and modulating the pseudo-random noise code to the double-sideband probe light to obtain spread spectrum double-sideband probe light; the spread spectrum double-sideband detection light enters the sensing optical fiber and is reflected back to the backward Rayleigh scattering light, and the backward Rayleigh scattering light and the spread spectrum double-sideband local oscillation light interfere with each other to output up-down sweep frequency beat frequency signals; separating the upper and lower sweep-frequency beat-frequency signals to obtain an upper sweep-frequency beat-frequency signal and a lower sweep-frequency beat-frequency signal; and after the upper sweep frequency beat frequency signal and the lower sweep frequency beat frequency signal are respectively decoded, a beat frequency signal is separated through band-pass filtering, the beat frequency signal is subjected to frequency mixing processing to obtain a frequency mixing signal after phase frequency noise suppression, and the frequency spectrum of the frequency mixing signal is analyzed.

The invention relates to the technical field of optical fiber sensing, and provides an improved moving average method applied to a distributed optical fiber vibration sensing system, and the method comprises the steps: continuously collecting a plurality of backward Rayleigh scattering curves; setting a plurality of different moving average window widths, and performing moving average processing on the plurality of backward Rayleigh scattering curves based on each moving average window width to obtain a plurality of scattering curves after moving average processing corresponding to each moving average window width; for each moving average window width, calculating the variance of the scattering curve after moving average processing at the same time point, and obtaining a variance sequence corresponding to the moving average window width; according to the variance sequence corresponding to each moving average window width, determining the corresponding moving average window width when the variance change tends to be stable, and taking the moving average window width as a target window width; and moving average processing is carried out on a plurality of acquired backward Rayleigh scattering curves by using a target window width, and a disturbance event on the optical fiber is positioned.

The invention relates to a road cavity detection and identification method and system based on multichannel optical fiber sensing. The method comprises the following steps: acquiring and storing Rayleigh scattering light time domain signals which are acquired by a DAS underground sensing system at different positions and different time periods of a detection road section and contain active knocking signals; determining a frequency range of the active knocking signal according to a frequency spectrum obtained after the Rayleigh scattering light time domain signal is subjected to fast Fourier transform processing; carrying out filtering processing on the Rayleigh scattering light time domain signal by adopting a finite impulse response band-pass filter to obtain a filtered signal; the filtered signal is input into a PhaseNetDAS model for seismic phase pickup, and an active source seismic phase is obtained; associating the active source seismic facies with the active source event to obtain a seismic facies report including event latitude and longitude, time and seismic facies arrival time; and inverting the velocity structure of the underground medium by using the seismic phase report by using a tomography method, and determining a road cavity detection and recognition result, thereby improving the accuracy of road cavity detection.

An integrated detection method based on a liquid-filled hollow-core optical fiber enhanced Raman signal comprises the following steps: positioning an optical coupling system, a liquid adapter and a forward Raman signal collection system along the same dovetail groove guide rail, and operating a sliding block fine adjustment mechanism to adjust the relative positions of the optical coupling system, the liquid adapter and the forward Raman signal collection system so as to enable an optical path to be axially aligned; the micro-flow injection system is operated, target liquid is conveyed to the liquid adapter through the micro-flow guide pipe, the liquid adapter keeps the collimation alignment relation between the hollow-core optical fiber and the laser, and then the target liquid is introduced into a fiber core of the hollow-core optical fiber; the laser light source is started to emit laser, and after the laser is collimated and focused through the optical coupling system, a Raman signal is excited and generated; operating a forward Raman signal collection system to capture a Raman signal output by the hollow-core optical fiber, filtering out an exciting light Rayleigh scattering signal in the Raman signal, and transmitting the purified Raman signal to a Raman spectrometer; and analyzing and processing the purified Raman signal, and outputting a detection result of the target liquid.

The utility model belongs to the technical field of optical fiber lasers, and relates to a multi-wavelength random optical fiber laser based on a four-port circulator and Brillouin-Rayleigh scattering, which is a closed-loop random optical fiber laser and comprises the four-port circulator, a seed laser is connected with the first port of the four-port circulator, and a seed laser is connected with the second port of the four-port circulator. The second port is connected with the Brillouin gain optical fiber, the third port is connected with the random Rayleigh scattering optical fiber, and the fourth port is connected with the optical fiber coupler; an erbium-doped fiber and a wavelength division multiplexer are connected between the Brillouin gain fiber and the fiber coupler, and a pump light port of the wavelength division multiplexer is connected with an output port of the 980nm laser. According to the utility model, the Brillouin gain optical fiber is subjected to Brillouin scattering, and the Rayleigh scattering of the random Rayleigh scattering optical fiber and the gain amplification of the erbium-doped optical fiber are combined, so that efficient and stable multi-wavelength output is realized, the number of output wavelengths is adjustable, the stability is high, and the device is suitable for a high-precision optical fiber sensing and dense wavelength division multiplexing system.

This invention discloses a method and system for intelligent weather image acquisition and recognition, specifically relating to the field of weather image recognition technology. It involves continuous polarization imaging of the sky region while simultaneously acquiring spatial attitude and temporal information; preprocessing the polarization image data and extracting Stokes parameters to obtain standardized sky polarization light field data; then using a theoretical Rayleigh scattering model to analyze the polarization degree distribution pattern at different wavelengths to obtain theoretical sky polarization pattern characteristics; based on the polarization light field data, identifying the spatial distribution of actual clouds, aerosols, and haze in the sky to form actual atmospheric composition distribution characteristics; extracting anomalous polarization regions through difference analysis between theoretical and actual characteristics, and accurately classifying halo polarization anomalies and scattering polarization anomalies based on geometric and spectral characteristics; generating ultralocal weather change early warning signals based on the classification results; thus improving the accuracy and real-time performance of early warnings for ultralocal anomalous weather phenomena.

This invention relates to an optical frequency domain reflectance distributed magnetic field sensing method based on image denoising, comprising the following steps: acquiring and processing Rayleigh scattering signals under no magnetic field and with magnetic field conditions using an OFDR system; performing Fast Fourier Transform on the reference signal under no magnetic field and the measurement signal under magnetic field conditions to obtain the distance domain signals at various positions of the corresponding optical fiber under the two magnetic field conditions; performing windowing and zero-padding operations; obtaining the local reference Rayleigh scattering spectrum and the local measurement Rayleigh scattering spectrum, and removing the DC component; performing cross-correlation calculation, arranging the grouped normalized cross-correlation results along the corresponding positions of the optical fiber to obtain the three-dimensional cross-correlation map at various positions of the optical fiber, and then projecting it onto a two-dimensional plane to obtain the original two-dimensional cross-correlation intensity map, and cutting it into blocks; denoising a certain block as the original block to obtain the integral image; obtaining the final denoised two-dimensional cross-correlation intensity map; and obtaining the frequency shift distribution of the magnetic field intensity spectrum.

The invention discloses an aircraft composite material structure health monitoring system and method, and relates to the field of aircraft material health monitoring, and the system comprises a DAS integrated optical module which is used for generating and transmitting an optical pulse pair subjected to heterodyne phase modulation to a single-mode optical fiber sensing network, and converting backward Rayleigh scattering light into an electric signal; the single-mode optical fiber sensing network is arranged on the surface of the aircraft composite material structure and is used for converting an acoustic emission signal containing the physical change of the aircraft composite material structure into an optical phase change signal by utilizing a coherent Rayleigh scattering effect; the digital signal processing module is used for carrying out signal processing on the electric signal by utilizing a heterodyne phase modulation method based on instantaneous frequency tracking so as to identify and position the damage of the aircraft composite material structure; and the alarm output module is used for outputting a damage position, a damage degree grade and an alarm signal of the airplane composite material structure in real time when the structural damage is detected, so that full-distribution and wide-range online accurate monitoring is realized.

This application relates to a Rayleigh scattering noise suppression method and system for a distributed acoustic wave detection system. The method includes: performing optical phase sinusoidal modulation on a high-coherence continuous laser output from a narrow-linewidth laser in an FBG-based distributed acoustic detection system according to a set modulation scheme using an optical phase modulator; the set modulation scheme is Csin(2πf m t), C is the phase modulation amplitude, f m The phase modulation frequency and satisfying f m τ = k, where τ is the time difference between two adjacent reflected light pulses being detected, t is time, and k is an integer. A highly coherent continuous laser beam with sinusoidal phase modulation is passed through an unbalanced interferometer to generate dual light pulses. These dual light pulses are then injected into an FBG array for distributed acoustic wave detection. This achieves low-noise distributed acoustic wave detection and effectively improves the detection performance of FBG-based distributed acoustic wave detection.

The utility model provides a special-shaped Rayleigh scattering panel lamp, which solves the problems that the traditional panel lamp mostly adopts a plane light guide plate structure, the light-emitting surface is a single plane, the shape is fixed, personalized scenes are difficult to meet and the like, and the main scheme is that the special-shaped Rayleigh scattering panel lamp comprises a light guide plate, an LED light source module, a reflection module and a lamp box, the light guide plate is integrally made of a transparent high polymer material, nanoscale scattering particles are arranged on the surface or in the light guide plate, the particle size of the nanoscale scattering particles is 10-500 nm, the nanoscale scattering particles are evenly arranged or the density of the nanoscale scattering particles is decreased progressively from the light source side to the far end, and the light emitting face of the light guide plate is of a non-planar special-shaped structure. The back faces of the light guide plates are attached through the reflection modules with the same curvature, the two ends of the light guide plates and the two ends of the reflection modules are embedded and fixed into the lamp box, and the LED light source modules are correspondingly arranged at the positions, where the light guide plates are embedded into the lamp box, of the light guide plates so as to be matched with the reflection modules for refraction.

The application discloses an optical link test method and device based on optical frequency domain reflection, which comprises the following steps: measuring echo optical signals of an optical link in an initial state by using a frequency domain reflectometer to obtain a first signal; measuring the echo optical signals of the optical link after changing the function state of the optical link again by using the frequency domain reflectometer to obtain a second signal; performing fast Fourier transform on the measured first signal and second signal respectively to obtain corresponding frequency domain signals and a distance-power relationship curve; converting the same frequency band in the two frequency domain signals into time domain signals by sliding window interception; performing cross-correlation operation on the time domain signals of the two groups of signals to obtain Rayleigh scattering frequency shift; and obtaining a distance-power distribution curve by calculation in combination with a coefficient. The application can realize fast and accurate measurement and calibration of optical field amplitude and phase parameters of an integrated system from a device level to a link level, and efficiently measure return loss, insertion loss, spectrum, delay and other parameters of an optical link on a chip.

The invention relates to an avionics system optical fiber communication link health management technology, and provides an airborne communication link fault positioning method and system based on an embedded OFDR, and the method comprises the steps: integrating an embedded OFDR function unit in an airborne network switching module, outputting frequency linear scanning continuous wave test light, and dividing the test light into detection light and reference light; the detection light is sequentially injected into each to-be-detected optical fiber link through the switch exchange matrix, and returned backward Rayleigh scattering light is received and interferes with the reference light to generate a beat frequency signal; a Rayleigh scattering distance map is obtained through analog-to-digital conversion and fast Fourier transform and is compared with a pre-stored health reference map in a differential mode, an abnormal event is recognized, and the position of a fault point is accurately positioned. According to the method, on-line monitoring with sub-millimeter resolution and no blind area can be achieved under the conditions of low power and no communication interruption, multi-link automatic polling, fault link switching and maintenance information reporting are supported, and the requirements for high reliability and BIT autonomous diagnosis of an airborne system are met.

The invention relates to the field of lighting equipment, and particularly discloses a green lamp which comprises a lamp shell, a blue sky module and a main lighting module, the main lighting module is arranged on the side face of the lamp shell, and the blue sky module is arranged at the top of the lamp shell; the blue sky module comprises a shell, a Rayleigh scattering light guide plate, a reflection unit and a first light source; the Rayleigh scattering light guide plate is arranged in the shell; the reflection unit is arranged on the back of the Rayleigh scattering light guide plate and can reflect light rays emitted from the back of the Rayleigh scattering light guide plate into the Rayleigh scattering light guide plate again on the surfaces with different distances from the back of the Rayleigh scattering light guide plate; the first light source is arranged on one side of the Rayleigh scattering light guide plate; the main lighting module comprises a reflective bowl and a second light source. The blue sky effect can be formed, the independent lighting module is arranged, the brightness in the irradiation range is uniform, the appearance is slim, and installation in a narrow space is facilitated.

This invention provides a wind erosion monitoring system and method based on distributed optical fiber, belonging to the field of optical-based wind and sand monitoring technology. It includes: constructing a wind erosion monitoring system comprising a linearly tunable laser, an optical isolator, a first coupler, an upper branch, a lower branch, a sand particle capture sensor, a photoelectric detection and acquisition module, and a host computer; utilizing the Rayleigh scattering signal of the linearly swept laser in the sensing optical fiber and the interference with a reference light, the vibration information distributed along the optical fiber is obtained by demodulating the beat frequency signal; combining the constructed sand particle impact and optical fiber coupling model, the dynamic strain generated by sand particle impact is converted into phase changes, realizing the acquisition of sand particle impact location, sand particle size, and sand particle quantity. This invention enables continuous distributed monitoring of wind and sand flows with high spatial resolution, and has advantages such as resistance to electromagnetic interference, strong environmental adaptability, and multi-parameter sensing, and can operate stably for a long time in harsh desert environments.

This improves the degradation of the cross-correlation coefficient caused by the error between the set frequency and the actual frequency of the light source, and makes it possible to improve the degradation of the measurement accuracy of strain and temperature. [Solution] The light source unit has a frequency-stabilized wavelength-tunable laser that generates continuous light, and a first optical coupler splits the continuous light generated by the light source unit into two, sending one to a second optical coupler and the other to an optical frequency measurement unit. The optical frequency measurement unit measures the frequency of the continuous light generated by the light source unit, and the second optical coupler further splits the continuous light split by the first optical coupler into two, sending one as probe light to the optical pulse generation unit and the other as local light to a detection unit. The detection unit measures the frequency change Δf by means of coherent time domain reflectometry and a means for heterodyne detection of the Rayleigh scattered light and the local light resulting from Rayleigh scattering of pulsed light in the fiber under test. max and means for acquiring the

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 utility model discloses a lighting module of a green lamp. The green lamp comprises a lamp body and a blue sky module. The lighting module is arranged in the lamp body and located on one side of the blue sky module. The blue sky module comprises a Rayleigh scattering plate and a first light emitting unit, and the first light emitting unit is used for emitting light to the Rayleigh scattering plate; the lighting module comprises a second light-emitting unit and a dimming assembly, the second light-emitting unit is arranged in the dimming assembly, and the dimming assembly comprises a reflection cup and / or a convex lens. According to the blue sky lighting lamp, the lighting module and the blue sky module are arranged in the different containing cavities respectively, the blue sky atmosphere lighting effect is provided, the blue sky lighting lamp can also be used as an indoor lighting lamp, and the height of the whole lamp is greatly reduced.

The invention discloses a reconfigurable singular point sensor based on high-Q-value artificial local surface plasmon and a working method. The sensor comprises an annular artificial local surface plasmon resonator, medium disturbance particles for regulating and controlling reconfigurable singular points, a medium substrate and a microstrip line located on the upper surface of the medium substrate. The annular artificial local surface plasmon resonator is suspended and supported by the metal ring, and the microstrip line is located near the resonator so as to effectively excite multi-mode resonance. By accurately regulating and controlling the positions of the two movable Rayleigh scatterers, three singular points of an octopole resonant mode, a ten-pole resonant mode and a twelve-pole resonant mode are continuously realized respectively, and the sensitivity of deep sub-wavelength target particles is remarkably enhanced. The sensor provided by the invention provides a highly flexible and reconfigurable platform for realizing a singular point sensing system with a single artificial local surface plasmon resonator, and paves a way for high-sensitivity particle detection from a microwave frequency band to a terahertz frequency band.

The invention discloses an optical fiber distributed voiceprint recognition method based on multi-scale decomposition and hybrid recombination, and belongs to the technical field of distributed optical fiber sensing and artificial intelligence, and the method comprises the following steps: constructing a DAS system, and employing the DAS system to demodulate and restore the phase and intensity signal of backward Rayleigh scattering light to obtain a voiceprint signal; converting the voiceprint signal into basic voiceprint feature representation by using a multi-scale decomposition and hybrid recombination network; performing multi-scale decomposition on the basic voiceprint feature representation, and extracting multi-scale long-term trend features and short-term detail information; performing feature extraction and fusion on the multi-scale short-term detail information to obtain multi-scale short-term detail features; carrying out adaptive weighting on the multi-scale short-term detail features, and carrying out hybrid recombination on the multi-scale short-term detail features and the long-term trend features to obtain hybrid recombination features; and outputting an identification result through a plurality of layers of linear mapping and a Softmax function on the hybrid recombined features. By adopting the method, the accuracy and the stability of voiceprint recognition are improved.

The application provides a preparation method of a blue light scattering plate, comprising the following steps: preparing a first dispersion liquid precursor containing inorganic sub-micron particles, wherein the material of the inorganic sub-micron particles is a plurality of different inorganic materials, and the particle size of the inorganic sub-micron particles is 120 nm-500 nm; mixing the first dispersion liquid precursor and a polymer emulsion to obtain a first dispersion liquid; preparing a second dispersion liquid precursor containing inorganic nano-particles, wherein the material of the inorganic nano-particles is the same as or different from that of the inorganic sub-micron particles, and the particle size of the inorganic nano-particles is 30 nm-120 nm; mixing the second dispersion liquid precursor and the polymer emulsion to obtain a second dispersion liquid; and preparing the first dispersion liquid and the second dispersion liquid into a blue light scattering plate. The blue light scattering plate prepared by the application has a good Rayleigh scattering effect. The application further provides a blue light scattering plate and application of the blue light scattering plate in a Rayleigh scattering sunlight lamp system.

The utility model provides a confocal microscopic Raman spectrometer wave number correction device, and belongs to the technical field of Raman spectrum detection. The correction device comprises a laser used for emitting laser; the lens assembly comprises a plurality of lenses, and the lens assembly is used for collimating and focusing the laser; the reflector assembly comprises a plurality of reflectors, the plurality of lenses and the plurality of reflectors are alternately arranged, and the reflector assembly is used for adjusting the light path direction of the laser; the attenuation sheet is arranged on a reflection light path in the reflector assembly and is used for attenuating the energy of the laser; the slit is arranged at a confocal position in the lens assembly, and the slit is used for screening Rayleigh scattering light in the attenuated laser; wherein the reflector assembly reflects the Rayleigh scattering light to the rotating grating assembly in the spectrometer. The correction device realizes a convenient and fast calibration process, and improves the calibration precision.

A temperature strain separable dynamic and static combined measurement distributed optical fiber sensing system, comprising: laser, optical modulator, radio frequency signal generator, optical filter, DFB laser, polarization controller, first acoustooptic modulator, depolarizer, erbium-doped fiber amplifier, two optical circulators, optical wavelength division multiplexer, receiving module, signal acquisition and processing module are arranged in sequence, the application carries out temperature sensing to the back Raman scattering light of the pulse while receiving the Rayleigh scattering light of the detection pulse, and controls the time interval of adjacent pump pulse and detection pulse to carry out three-bit pulse coding and decoding, so that the back Raman scattering signals of individual pulse in pulse pair are separated in time, and finally the simultaneous measurement of dynamic variable (vibration) and static variable (temperature, static strain) is realized and the spatial resolution of measurement is ensured not to be lost.

The invention provides a method and a system for positioning an abnormal attenuation position of an optical fiber. The method comprises the following steps: acquiring a real value of receiving optical power and a real value of back Rayleigh scattering light power; determining a receiving optical power normal reference value and a back Rayleigh scattering power normal reference value according to the incident fiber power of the incident continuous service optical signal, and calculating a difference value between the receiving optical power normal reference value and a receiving optical power true value to obtain a receiving optical power drop amount; calculating the instantaneous transmittance by using the linear relationship between the drop amount of the received optical power and the instantaneous transmittance of the incident continuous service optical signal from the transmitting end to the receiving end and combining the normal reference value of the received optical power; and calculating the difference value between the normal reference value of the back Rayleigh scattering power and the true value of the back Rayleigh scattering power to obtain the drop amount of the back Rayleigh scattering power, and calculating the abnormal attenuation position of the optical fiber according to the linear relation between the drop amount of the back Rayleigh scattering power and the abnormal attenuation position of the optical fiber.

The invention discloses an optical waveguide structure composite material based on SAN resin and a preparation method thereof. The raw material composition is as follows: 60-70 parts of SAN resin; 30 to 40 parts of PMMA (polymethyl methacrylate) resin; 0.1 to 1 part of modified nano CeO2; 1 to 5 parts of a maleic anhydride grafted SEBS compatilizer; and 0.1 to 1 part of an antioxidant. According to the material, through a double-effect anti-reflection mechanism of a synergistic effect, the light transmittance gt of a key ultraviolet band is remarkably improved; on one hand, the refractive index difference between the PMMA fibers which are continuously distributed in the axial direction and the SAN matrix is utilized to guide ultraviolet light to generate total internal reflection conduction at an interface, and the inherent strong ultraviolet absorption characteristic of the SAN matrix is effectively avoided; on the other hand, by means of the Rayleigh scattering effect generated by the CeO2 nanoparticles which are subjected to double surface modification and are uniformly dispersed, the transmission efficiency of ultraviolet light is selectively enhanced. According to the preparation method, a slit die head is adopted for extrusion preforming, and key processes of longitudinal hot stretching (inducing PMMA fibrosis) and water bath shock cooling (locking an optical waveguide microstructure) are combined, so that precise construction and large-scale preparation of an optical waveguide structure in the material are realized. The prepared composite material has high ultraviolet light transmittance, excellent mechanical properties and good chemical resistance, and has wide application prospects in the fields of micro-fluidic chips, electrophoresis plates, medical instruments and optoelectronic devices.