464 results about "Broadband light source" patented technology

The invention provides a multi-layer optical film detection method, device and equipment and a storage medium, and the method comprises the steps: obtaining a polarization phase difference signal of transmission light and reflected light through multi-angle incidence irradiation of a multi-band programmable laser source, and recording the polarization ellipticity parameter change; then combining confocal microscopic interference and polarization analysis to determine a space coordinate and a stress distribution diagram of a stress abnormal region; continuously irradiating in a photo-thermal coupling environment through a broadband light source, and monitoring interference signals, polarization states and temperature changes to obtain dynamic evolution characteristics; and finally, performing a simulation test on the multi-layer optical film in a system environment with preset optical axis arrangement and light beam energy distribution, obtaining an in-situ polarization state and interference pattern data, and evaluating the optical performance of the film layer. According to the invention, potential defects can be positioned under high resolution, and the reliability and imaging quality of the film layer under complex application conditions can be accurately evaluated.

The invention provides a wavelength division multiplexing-fused multi-core optical fiber temperature detection method and system. Wherein the broadband light source is divided into multiple wavelength channels through wavelength division multiplexing, and a wavelength-fiber core mapping relation is established, so that each fiber core of the multi-core optical fiber transmits a single-wavelength optical signal. An optical fiber is integrated to the surface of an object according to a three-dimensional path, each fiber core covers a plurality of sensing sub-areas, the wavelength drift amount caused by temperature is extracted by detecting the attenuation characteristic of an optical signal at a bending position, the wavelength drift amount is converted into a temperature value in combination with a calibration curve, and a temperature gradient model bound with the fiber core position is constructed. And further performing spatial solution by using fiber core spacing, wavelength mapping and transmission time delay parameters, establishing a corresponding relationship between the coordinates of the sensing sub-regions and the temperature, and finally reconstructing three-dimensional temperature field distribution. According to the technical scheme provided by the invention, high-resolution dynamic reconstruction and gradient analysis of a three-dimensional temperature field on a complex surface are realized through wavelength-space two-dimensional decoupling.

The invention discloses an optical fiber line fault detection method and system, and the method comprises the steps: employing broadband light sources at the two ends of an optical fiber in an optical fiber network at the same time, and carrying out the frequency coding of a signal in the broadband light sources, and obtaining an optical signal; collecting optical fiber sensing data; performing multi-mode acquisition on the optical signal to obtain multi-mode optical signal data; preprocessing the multi-mode optical signal data and the optical fiber sensing data to obtain clear signal data; analyzing and fusing the clear signal data to obtain fused data; and inputting the fusion data into a pre-purchased fault identification model, and outputting a fault type. According to the method, through technologies of multi-modal data fusion, high-frequency signal extraction, physical model constraint, feature compression and the like, the problems that the complex fault recognition capability is insufficient and the stability of the model is weakened by environmental interference are effectively solved, and the precision, robustness and generalization capability of optical fiber line fault detection are remarkably improved.

The invention relates to the cross technical field of atmospheric science and communication technology, in particular to an atmospheric refraction and waveguide environmental parameter detection and prediction method and device, and the method comprises the following steps: carrying out the power distribution of a light beam of a broadband light source through employing a light splitting element based on the emission of the broadband light source, and forming a detection light beam and a reference light beam, and guiding the detection light beam to pass through a preset open atmosphere optical path, and guiding the reference light beam to pass through a known refractive index stabilizing medium or a vacuum pipeline. The detection light beam and the reference light beam are formed through light splitting of the broadband light source, the detection light beam penetrates through the open atmosphere path, the reference light beam passes through the stable medium, Fourier transform is carried out on interference signals of the two light beams to extract wavelength phase difference mapping data, and tiny optical path change caused by atmospheric refractive index disturbance can be captured. Compared with the traditional single-point or single-path measurement, the sensing sensitivity and the measurement dimension of the atmospheric refractive index spatial nonuniformity are improved by using the broadband spectral information.

The invention discloses a PCB (printed circuit board) back drilling stub length detection device and method, and belongs to the technical field of PCB detection, the PCB back drilling stub length detection device comprises a broadband light source, the output end of the broadband light source is connected with an optical fiber coupler, and one end, deviating from the broadband light source, of the optical fiber coupler is respectively connected with a first optical fiber collimator and a second optical fiber collimator; the first optical fiber collimator is provided with a lens and a reflector on an optical transmission path; the second optical fiber collimator is provided with a galvanometer on a light transmission path, and a scanning lens is arranged in the light emitting direction of the galvanometer; and the optical fiber coupler is also connected with a spectrograph. On the basis of the low-coherence light interference principle, the PCB back drilling stub length detection device is designed, the output power and the output bandwidth of a broadband light source are correspondingly adjusted, the insertion loss of an optical fiber coupler is controlled, the collection rate of a spectrograph is adjusted, finally, the axial resolution reaches 5 micrometers, the transverse resolution reaches 10 micrometers, and the requirements that the diameter is smaller than 0.1 mm, and the detection precision is larger than 0.1 mm can be met. And detecting the stub length of the deep micropore with the depth of less than 10mm.

The invention discloses a multi-parameter coupling detection method of an integrated optical sensor and related equipment. The detection method comprises the following steps: injecting different trace medicament combinations into a to-be-detected sample in a plurality of micro-fluidic sub-channels according to a preset time sequence; performing phase shift coding acquisition on the differential optical response signal, splitting a broadband light source into a plurality of wavelength subintervals, and generating a coded light signal with a preset phase shift amount; calculating a cross-correlation function between the channels, and performing signal amplification or suppression processing on the channel group with high coupling degree; multi-dimensional feature extraction is carried out, and the differential interference amount, the amplitude ratio and the phase synchronization degree between channels are calculated; baseline drift and noise distribution are monitored in a preset time window, and parameter adjustment is carried out; and performing self-learning evaluation on the detection data, updating identification model parameters, and generating a multi-parameter fingerprint spectrum. According to the technical scheme, the problems of signal aliasing and insufficient sensitivity in multi-parameter detection are effectively solved, and high-precision synchronous detection can be carried out on various target objects.

The invention discloses a calibration device with a spectrum self-calibration function and a high-resolution spectrum calibration method thereof. The device comprises a narrow-band light source, a broadband light source, an optical fiber isolator, a coupler, an interference system, a multi-way switch, an FP (Fabry-Perot) cavity, a collimator, an orthogonal dispersion system and a computer, wherein the orthogonal dispersion system consists of a cylindrical lens, a reflector, a virtual phase array, a grating, a focusing lens and an industrial camera; according to the device, different light source paths are gated, FP cavity modulation and orthogonal dispersion system light splitting are utilized, and an industrial camera is combined to receive light signals. According to the method, the mapping relation between pixels and wavelengths can be established, the two-dimensional spectrum is compressed into the one-dimensional calibration spectrum through light intensity modulation and normalization processing, the calibration process of the orthogonal dispersion system is simplified, and the measurement precision is improved; and system drift can be compensated in real time through self-checking calibration, and the reliability of a measurement result is ensured, so that accurate calibration and measurement of a high-resolution spectrum can be realized.

A system includes an illumination system, an optical element, a switching element and a detector. The illumination system includes a broadband light source that generates a beam of radiation. The dispersive optical element receives the beam of radiation and generates a plurality of light beams having a narrower bandwidth than the broadband light source. The optical switch receives the plurality of light 5 beams and transmits each one of the plurality of light beams to a respective one of a plurality of alignment sensor of a sensor array. The detector receives radiation returning from the sensor array and to generate a measurement signal based on the received radiation.

A LSP broadband light source is disclosed. The light source may include a gas containment structure. The light source may include multiple jet nozzles, wherein the jet nozzles are configured to generate supersonic gas jets and direct the supersonic gas jets to collide within the gas containment structure to form a localized high-pressure region at the collision point. The light source may include a primary laser pump source, wherein the primary laser pump source is configured to direct a primary pump beam to a localized high-pressure region formed at the collision point. The light source may include a pulsed-assisting laser source, wherein the pulsed-assisting laser source is configured to direct a pulsed-assisting beam to the localized high-pressure region at the collision point. The light source may include a light collector element configured to collect broadband light emitted from the plasma.

The invention provides a diaphragm type optical fiber liquid level sensing demodulation device and method based on a microwave photon technology, and the device comprises a broadband light source, a circulator, a diaphragm type optical fiber liquid level sensor, an erbium-doped optical fiber amplifier, a polarization controller, a DC power supply, a radio frequency source, an electro-optical modulator, a dispersion compensation optical fiber, a photoelectric detector and a power meter. The broadband light source is connected with a first port of the circulator, a second port of the circulator is connected with the diaphragm type optical fiber liquid level sensor, a third port of the circulator is connected with the erbium-doped optical fiber amplifier, the erbium-doped optical fiber amplifier is connected with the polarization controller, and the polarization controller is connected with the input end of the electrooptical modulator. The radio frequency source is connected with the modulation input of the electro-optical modulator, the direct current power supply is connected with the bias voltage input of the electro-optical modulator, the output of the electro-optical modulator is connected with the photoelectric detector through the dispersion compensation optical fiber, and the photoelectric detector is connected with the power meter, so that the measurement range is expanded while the sensing sensitivity and the resolution ratio are improved.

The invention relates to the field of optical measurement, in particular to a reflective interference film thickness measurement method and system for eliminating back scattering of a transparent substrate, and the method comprises the following steps: transmitting a light beam through a low-coherence-length broadband light source, and forming linearly polarized light through polarization modulation; focusing the light beam to the surface of the film through a confocal optical system; collecting reflection interference signals of the upper surface and the lower surface of the film; spatial filtering, low-coherence gating and polarization control are used for cooperatively inhibiting back scattering of the substrate. And processing the acquired interference signal, and calculating to obtain film thickness information. According to the invention, triple inhibition mechanisms are adopted for synergistic effect, and the method comprises the following steps: spatial filtering: shielding out-of-focus back reflected light through a confocal small hole; low-coherence gating: using a short coherence length to naturally suppress a reflected signal beyond a coherence range; and polarization control: further weakening stray light interference through polarization state matching, and effectively suppressing back scattering of the substrate.

The invention discloses a rotor and stator axial clearance online measuring device and method based on optical carrier microwave interference. The measuring device comprises a broadband light source, a first polarization maintaining optical fiber, an electro-optical modulator, a second polarization maintaining optical fiber, an optical fiber circulator, a first single-mode optical fiber and a coated optical fiber probe which are connected in sequence, and the coated optical fiber probe directly faces the axial end face to be measured; a first port of the optical fiber circulator is connected with the second polarization maintaining optical fiber, a second port of the optical fiber circulator is connected with the first single-mode optical fiber, and a third port of the optical fiber circulator is sequentially connected with the second single-mode optical fiber, the photoelectric detector, the signal conditioning unit, the signal acquisition unit and the digital processing unit; the signal acquisition unit is connected with the micro-control unit, the micro-control unit is connected with the microwave frequency sweep signal generation unit, and the microwave frequency sweep signal generation unit is connected with the electro-optical modulator. According to the invention, non-contact on-line high-precision measurement of the axial clearance of the rotor and the stator of the aero-engine under the conditions of limited measurement space and complex signal leading-out path can be realized.

The invention relates to a method for calibrating a light source and a spectrometer. A calibration light source includes: a broadband light source that emits light in a broad spectral range; and a filter receiving the light emitted by the broadband light source and providing structured light by applying an attenuation pattern on the received light exhibiting pattern characteristics at a plurality of spectral reference lines, the calibration light source is configured such that the emission spectrum of the structured light emitted by the calibration light source exhibits unique identifiable emission spectrum characteristics corresponding to the mode characteristics at a plurality of spectral reference lines. A method of calibrating at least one spectrometer using the calibration light source is also disclosed.

The invention discloses a vernier effect and Sagnac ring-based dual-parameter optical fiber sensor, which belongs to the technical field of optical fiber sensors and comprises a broadband light source SLED (1), a coupler (2), a sensing structure A (3), a circulator (4), a sensing structure B (5) and a spectrum analyzer (6). The device comprises a first single-mode fiber (301), a polarization-maintaining photonic crystal fiber (302), a few-mode fiber (303), a fiber Bragg grating (304), a second single-mode fiber (501), a first hollow-core fiber (502) and a second hollow-core fiber (503). Parasitic interference is avoided by grinding the end face of the hollow-core optical fiber, and the reliability of the sensor is improved; two transmission peaks appear on the fiber bragg grating inscribed on the few-mode fiber through different mode numbers in the few-mode fiber, and gas concentration and temperature sensitivity of two signals can be calculated by observing drifting of the transmission peaks; an optical vernier effect can be formed through superposition of a Sagnac interferometer formed by polarization-maintaining photonic crystal fibers and an F-P interferometer formed by hollow core dislocation, and the gas concentration and the temperature sensitivity of the sensor are improved. The sensor has the characteristics of high sensitivity, wide measurement range, simple structure, small size and the like.

A miniaturized interferometric integrated photonic gyroscope structure with top silicon oxide, middle silicon oxide and bottom silicon oxide deposited on a silicon substrate comprises broadband optical source or a semiconductor optical amplifier with silicon nitride ring resonator wavelength filter, connected with a thin film lithium niobate or piezoelectrically actuated silicon nitride phase modulator vertically coupled with a silicon nitride waveguide spiral loop. The silicon nitride waveguide spiral loop is patterned on thin bottom oxide layer with air trenches below it and connected with a germanium detector either through photonic wire bonding or vertically integrated through reflecting mirror embedded into silicon wafer. Various methods of coupling alternative materials are described and the potential of connecting several spiral waveguides for enhanced sensitivity in a gyroscope application.

The present invention provides a material level measurement system and method based on an FBG temperature sensor array. The measurement system includes an FBG demodulator, an FBG temperature sensor array, and a control terminal; the FBG demodulator transmits an optical signal to the FBG temperature sensor array through a broadband light source, and the array reflects a characteristic spectrum signal in real time, which is transmitted to a photoelectric conversion module through an optical circulator, and then the spectrum data is processed and plotted at high speed through an FPGA acquisition module, and then the central wavelength of the reflected light of the FBG measuring point is obtained by analyzing the discrete point Gaussian fitting peak search algorithm, and finally converted into a temperature value through a wavelength-temperature function, and then the temperature information is transmitted to the control terminal for information processing, so as to obtain accurate material level information in the raw material tank. The present invention adopts the coupling of laser measurement technology and optical fiber sensing technology, and makes full use of the linearized inversion relationship between the laser direct measurement parameters and the material level measurement value. Through the software algorithm processing flow, accurate material level measurement can be achieved quickly, in real time, and with high precision.

The invention provides a magneto-optical measurement system which can be applied to the technical field of optical measurement. The system comprises a broadband light source, a broadband light source performance regulation and control module, a polarization-maintaining circulator, an optical phase modulation and demodulation module, a magneto-optical spectrum acquisition module and a signal detection module, an initial optical signal generated by the broadband light source is regulated and controlled by the broadband light source performance regulation and control module to obtain a stable optical signal, and the stable optical signal passes through the polarization-maintaining circulator and is transmitted to the optical phase modulation and demodulation module. The light enters the optical phase modulation and demodulation module and is modulated to generate an emergent light beam; the emergent light beam enters a magneto-optical spectrum acquisition module, and a reflected light beam on the sample is obtained after magneto-optical signal modulation; the reflected light beam passes through the optical phase modulation-demodulation module, interference is generated after demodulation, and an interference signal is generated; and the interference signal enters the signal detection module through the polarization-maintaining circulator and is recorded by the signal detection module, and a magneto-optical spectrum is generated.

The invention discloses a Fabry-Perot interference type hydrogen detection device and method. The Fabry-Perot interference type hydrogen detection device comprises a broadband light source, a spectrograph, an optical fiber coupler, a sensing probe, a test gas chamber and a reference probe, the sensing probe and the reference probe are provided with sensor structures based on an optical fiber Fabry-Perot cavity, and the optical fiber coupler outputs input light emitted by the broadband light source to the sensing probe and the reference probe through a port A, a port B and a port C; light reflected by the optical fiber Fabry-Perot cavities of the sensing probe and the reference probe is output to a spectrograph through a D port, so that an interference spectrum is demodulated; hydrogen to be detected is mixed with air, then enters the test gas chamber through the gas flow rate controller, and is discharged from the outlet; the sensing probe adopts an anodic aluminum oxide / palladium film as a terminal reflector of a Fabry-Perot cavity, and an interference spectrum is detected through a spectrograph to obtain hydrogen concentration information in the environment; the reference probe adopts two single-mode optical fiber end faces to align in a sleeve and form an air Fabry-Perot cavity, and the reference probe only provides a stable reference spectrum to realize a vernier effect.

The invention discloses a method for measuring fan blade root stress based on a fiber bragg grating sensor. According to the method, 6-10 key measurement points are selected in a blade root area of a fan blade, a pair of FBG sensors is installed at each measurement point, one FBG sensor is used for stress measurement (affected by strain and temperature at the same time), the other FBG sensor is used for temperature compensation, and decoupling of temperature and strain signals is achieved. The system adopts a single-mode optical fiber, a broadband light source (the wave band is 1525-1565 nm, and the power is 10-20 mW) and a high-resolution spectrum analyzer (the resolution is smaller than or equal to 1 pm, and the sampling rate is larger than or equal to 100 Hz or 1 kHz) to collect optical signals reflected by an FBG sensor in real time, measured wavelength shift is converted into accurate strain data through temperature compensation and a strain calculation formula, and the optical signals are transmitted to the FBG sensor. And calculating a stress value by combining the Young modulus and Poisson's ratio of the material. The method has the advantages of being high in precision, high in real-time performance, resistant to electromagnetic interference and suitable for seaborne, high-altitude and other severe environments, and reliable data support can be provided for dynamic stress monitoring, fatigue life prediction and fault early warning of the fan blade.

The invention relates to an all-silicon metasurface infrared optical filter based on a bound state in a quasi-continuous domain and a manufacturing method of the all-silicon metasurface infrared optical filter. Belongs to the technical field of micro-nano optics, and particularly relates to the technical field of all-silicon metasurface infrared optical filters. The problem that application of the metasurface optical filter under an infrared broadband light source is limited is solved. The all-silicon metasurface infrared optical filter based on the bound state in the quasi-continuous domain comprises a self-supporting silicon frame, a monocrystalline silicon thin film and a nanometer cavity array. The monocrystalline silicon thin film is attached to the self-supporting silicon frame, and a nano cavity array is etched on the surface of the monocrystalline silicon thin film; one surface of the self-supporting silicon frame attached with the monocrystalline silicon film is a light incident surface, and the other surface is a light emergent surface; incident light is irradiated to the nano cavity array on the monocrystalline silicon film in a normal or a certain incident angle to excite a surface resonance mode and a bound state in a quasi-continuous domain, the surface resonance mode and the bound state in the quasi-continuous domain are subjected to interference coupling under the same resonance frequency to form a space overlapping mode, and the incident light is modulated and emitted from the other face of the self-supporting silicon frame.

The present disclosure provides a mode control system and method for controlling an output mode of a broadband light source including a photonic crystal fiber (PCF). The mode control system includes: at least one detection unit configured to measure one or more parameters of radiation emitted from a broadband light source to generate measurement data; and a processing unit configured to evaluate the mode purity of the radiation emitted from the broadband light source from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimizing one or more pump coupling conditions of the broadband light source. The pump coupling condition relates to the coupling of a pump laser beam with respect to an optical fiber core of the photonic crystal fiber.

The invention discloses a Fourier photoacoustic gas detection device and method, and belongs to the technical field of gas detection. In order to solve the problems that the anti-interference capability of an existing Fourier transform photoacoustic spectrum on a sound signal is limited and the detection sensitivity is low, the Fourier photoacoustic gas detection device is designed, and a super-continuum spectrum broadband light source is used as an excitation light source of a photoacoustic effect; uniform intensity modulation of wide-spectrum light is achieved through the intensity modulation assembly, and phase modulation is achieved through the interferometer assembly. The broadband interference light emitted through double modulation acts with gas molecules to generate wide-spectrum mixed sound waves, and the quartz tuning fork sound measurement assembly extracts resonance components in the wide-spectrum mixed sound waves and converts the resonance components into electrical signals; the generated electrical signal is processed by the signal amplification assembly, the phase-sensitive demodulation assembly and the Fourier transform assembly in sequence, and component discrimination and concentration inversion of the target gas are realized by the processed signal.

The invention provides a Sagnac optical fiber vibration positioning structure based on a dual polarization structure. Comprising a broadband light source, a first polarization beam splitter, a first optical fiber coupler, a second optical fiber coupler, a first optical fiber delay ring, a second optical fiber delay ring, a third optical fiber coupler, a fourth optical fiber coupler, a second polarization beam splitter, a third polarization beam splitter, a vibration sensing optical fiber, a first reflector, a second reflector, a first photoelectric detector and a second photoelectric detector. According to the positioning structure, X polarized light and Y polarized light sense the same vibration signal in the same vibration sensing optical fiber, two paths of independent interference signals with fixed time delay are formed, and the fixed time delay is related to the vibration position; by demodulating the phase information of the two paths of interference light intensities and performing cross-correlation time delay estimation, the specific position of the external vibration signal can be positioned. The problem that a traditional Sagnac interference type optical fiber vibration sensing system is complex in vibration positioning algorithm and limited by vibration frequency is solved.

The invention discloses a methane sensor based on a micro-nano optical fiber coupler and a methane concentration measuring method. The methane sensor comprises a broadband light source, a sensing unit and an oscilloscope which are sequentially connected from front to back, the sensing unit comprises a micro-nano optical fiber coupler, an indium oxide coating and a silver coating, and the silver coating and the indium oxide coating are sequentially arranged in the middle of the micro-nano optical fiber coupler from inside to outside; one end of the micro-nano optical fiber coupler is provided with a P1 port and a P2 port which are used as input ends, and the other end of the micro-nano optical fiber coupler is provided with a P3 port and a P4 port which are used as output ends. Ports P1 and P2 of the micro-nano optical fiber coupler are connected with the output end of the broadband light source, and a port P3 of the micro-nano optical fiber coupler is connected with the oscilloscope. The methane concentration is calculated based on the optical interference principle of the micro-nano optical fiber coupler, and the influence of external factors such as volume, pressure and temperature is eliminated. The device has the advantages of being small in size, high in external interference resistance and good in corrosion resistance, can better adapt to various environments, and has wide development space and good practicability.

A calibration light source includes: a broad band light source emitting light in a broad spectral range; and a filter receiving light emitted by the broad band light source and providing structured light by imposing an attenuation pattern exhibiting pattern features at multiple spectral reference lines on the received light such that an emission spectrum of the structured light emitted by the calibration light source exhibits distinct, identifiable emission spectrum features corresponding to the pattern features at the multiple spectral reference lines. A method of calibrating at least one spectrometer using the calibration light source is further disclosed.

This invention relates to the field of optical imaging and detection technology, specifically providing a broadband snapshot-type polarization interferometry imaging detection system and method for breast tumors. A broadband light source illuminates a breast tumor tissue sample. The reflected signal light is collected and collimated by a pre-optical system, then sequentially passes through a first and a second ray shaping unit for two shearing and two polarization state transformations, resulting in two beams of linearly polarized light and two beams of circularly polarized light. These beams are imaged by an imaging lens to an area array detector to obtain a polarization interferogram, which is then demodulated to obtain all Stokes parameters of the breast tumor tissue sample. This invention achieves broadband snapshot imaging of breast tumors with all Stokes parameters without using an analyzer, doubling the light throughput compared to traditional polarization imaging instruments using analyzers. Furthermore, this invention has advantages such as compact structure, no moving parts, easy assembly and adjustment, and no need for image registration.

The invention relates to the technical field of spacecraft structure micro stress detection, in particular to a spacecraft structure micro stress detection device and a use method thereof, and the spacecraft structure micro stress detection device comprises a displacement amplification structure, a single mode fiber, a reflector, a broadband light source and a spectrum analyzer. An optical resonant cavity formed by an optical fiber end face and a lens is combined with a displacement amplification structure, when stress acts on a spacecraft structure, the cavity length of the Fabry-Perot resonant cavity changes, so that phase movement of light is caused, and accurate measurement of the stress can be achieved by detecting the phase movement. The antenna has extremely high anti-electromagnetic interference capability, and can work stably in a complex space environment. Even under the condition of violent temperature change, high measurement accuracy can be kept, and detection of tiny stress can be achieved through the amplification effect of the displacement amplification structure. And the stress characteristic signal and the background noise can be effectively separated, so that the detection reliability is remarkably improved.

The invention provides an integrated sensor for vibration, temperature and strain monitoring and a demodulation method thereof, and belongs to the technical field of optical measurement. Comprising an optical fiber, the optical fiber is arranged on a measured object, and three Bragg gratings are connected in series on the optical fiber; the broadband light source emitter is connected with the optical fiber which is connected with the demodulation device. The broadband light source emitter emits light signals to irradiate the three Bragg gratings on the optical fiber, vibration, temperature and strain signals of a measured object are measured in real time, and the three Bragg gratings carry measured signal spectrums and reflect the measured signal spectrums back to the demodulation device for demodulation. The three key parameters of vibration, temperature and strain of the measured object are measured at the same time, and the actual state of the monitored object can be reflected more comprehensively compared with an existing single-parameter or multi-independent-sensor respective measurement mode. The problem of misjudgment of the health condition of the structure caused by insufficient monitoring of a single parameter is avoided, and richer and more accurate data support is provided for accurately evaluating the safety, reliability and residual life of the structure.

The invention aims to provide a dual-channel Fabry-Perot cavity optical fiber pressure sensor with high reliability and high precision and a preparation method thereof, the dual-channel Fabry-Perot cavity optical fiber pressure sensor comprises a base, a pressure-sensitive diaphragm and an optical fiber, the pressure-sensitive diaphragm is hydrogel based on a PVA-boric acid complex structure, a carbon dot fluorescent nano-material is doped in the hydrogel, and the optical fiber is doped in the carbon dot fluorescent nano-material. The dual-channel optical system comprises a pressure sensing channel for detecting the change of a Fabry-Perot cavity interference spectrum by adopting a broadband light source, and a damage monitoring channel for exciting carbon dot fluorescence by adopting an excitation light source and judging diaphragm damage through the change of fluorescence signal intensity. The pressure-sensitive diaphragm based on a PVA-boric acid complex structure has a self-repairing function and can drift for a long time; 0.5% F.S. / month, the service life of the sensor is prolonged, and the accuracy of pressure acquisition is improved; meanwhile, a carbon dot fluorescent nano-material with excellent biocompatibility is doped into the pressure-sensitive diaphragm, so that real-time self-monitoring of optical damage is realized, and the carbon dot fluorescent nano-material is used as an auxiliary function to improve the reliability of pressure acquisition of the sensor.

The invention relates to an optical fiber photo-thermal spectrum sensing system for simultaneously detecting multi-component dissolved gas in transformer oil, which is suitable for the fields of optical fiber sensing, power system state monitoring and the like and comprises a homodyne interference light path module, a pumping module and a capillary oil extraction module. The invention provides an optical fiber photo-thermal spectrum sensing system for simultaneously detecting multi-component dissolved gas in transformer oil, a broadband light source is combined with FBG filter filtering and AOM intensity modulation as pumping, multi-component gas can be detected, in order to avoid crosstalk among component signals, different modulation frequencies are set for light sources with different wavelengths, and the optical fiber photo-thermal spectrum sensing system can be used for simultaneously detecting multi-component dissolved gas in transformer oil. The simultaneous real-time detection of each component can be realized; in order to concentrate pumping energy to increase sensitivity, a capillary optical fiber with a punched side face is adopted as a detection cavity, and oil circulation between the detection cavity and a transformer oil tank is achieved through an oil pump.