1363 results about "Single-mode optical fiber" patented technology

The invention provides a temperature self-compensating intrusive optical fiber pressure guide wire and an FFR wireless monitor, and belongs to the technical field of optical fiber sensing. Comprising a first hollow guide wire section, a second hollow guide wire section, a third hollow guide wire section and an FBG-FP cascade optical fiber sensor which are sequentially arranged, the first guide wire section is used for guiding the second guide wire section and the third guide wire section in a blood vessel; the second guide wire section and the third guide wire section are hollow and are communicated with each other; the FBG-FP cascade optical fiber sensor is arranged in the second guide wire section and extends towards the inner direction of the third guide wire section; the FBG-FP cascade optical fiber sensor comprises a multimode optical fiber, a hollow optical fiber and a single-mode optical fiber which are arranged in sequence, and the single-mode optical fiber is provided with a fiber bragg grating (FBG); the FBG-FP cascade optical fiber sensor is used for measuring temperature and strain signals in a blood vessel at the same time. The method is particularly suitable for parameter measurement of the area before and after the stenosis lesion in the blood vessel.

The invention discloses an optical fiber Fabry-Perot sensor for detecting C4F7N gas and decomposition products thereof, belongs to the technical field of C4F7N gas detection, and solves the problem of how to improve the sensitivity of the optical fiber Fabry-Perot sensor for detecting the C4F7N gas and the decomposition products thereof. According to the optical fiber Fabry-Perot sensor for detecting the C4F7N gas and the decomposition products thereof, the Fabry-Perot cavity is formed by the interval between the end face of the single-mode optical fiber and the surface of the groove, emergent light of the single-mode optical fiber is reflected by the surface of the groove, the reflected light is converged by the groove, the loss of the reflected light is reduced, and the detection accuracy of the C4F7N gas and the decomposition products thereof is improved. Gold is uniformly sputtered on one surface of the groove of the sensing diaphragm device layer to form a layer of reflecting film, so that the reflectivity is further improved, reflected light is efficiently coupled into the single-mode optical fiber, the contrast ratio of a light interference peak is improved, and the detection sensitivity of the sensor is further improved; the sensor is simple in structure, small in size, high in reliability and capable of achieving high-sensitivity measurement of the C4F7N gas decomposition products.

The invention discloses a C4F7N gas optical fiber Fabry-Perot sensor, a sensitivity demodulation system and a sensitivity demodulation method, belongs to the technical field of C4F7N gas detection, and solves the problem of how to improve the sensitivity of the C4F7N gas optical fiber Fabry-Perot sensor. A Fabry-Perot cavity is formed by a gap between the end face of a single-mode optical fiber of the C4F7N gas optical fiber Fabry-Perot sensor and the surface of a groove; emergent light of the single-mode optical fiber is reflected by the surface of the groove, and the groove converges the reflected light, so that the loss of the reflected light is reduced, and the detection sensitivity of the sensor is improved; the sensor is simple in structure, small in size and high in reliability; according to the sensitivity demodulation system, the resonant wavelength drift direction is judged based on a twice multi-frequency correlation demodulation method, and then the sensitivity of the sensor is represented according to a peak value tracking method; the cavity length of the sensor can be demodulated by only one enveloped wavelength range, so that the requirement on the bandwidth of a light source is reduced, and the equipment investment cost is reduced.

The invention relates to the field of integrated optical fiber microscopic endoscopy, in particular to an all-optical-fiber light beam modulation and collection system based on double super lenses and a design method of the all-optical-fiber light beam modulation and collection system. The system comprises a single-mode optical fiber, a coreless optical fiber for beam expansion and two super lenses (a super lens 1 and a super lens 2) with different functions. The super lens 1 is arranged on the end face of the fiber core of the single-mode optical fiber and focuses output exciting light to form extremely small waist spots, and the divergence angle of light beams is increased. The super lens 2 is arranged on the end face of the coreless optical fiber beam expanding area and used for refocusing the exciting light and focusing the collected fluorescence to the focus position of the super lens 1 at the same time, and the fluorescence is incident to the fiber core in parallel through the super lens 1. According to the invention, a double-super-lens system based on a high numerical aperture (NA) is fully utilized, wavefront modulation is carried out, the length of a beam expanding area is adjusted, and the loss of fluorescence in the beam expanding area is reduced, so that the collection efficiency of the fluorescence is remarkably improved, and an innovative solution is provided for the design of a super-lens-based optical fiber optical system.

The invention relates to a wide-temperature high-precision optical acceleration sensitive chip and sensor based on a microcavity interferometer principle and a manufacturing method thereof, the wide-temperature high-precision optical acceleration sensitive chip comprises a first substrate, a second substrate and a third substrate, an optical fiber mounting seat and a light through hole are formed on the first substrate, a beam structure and an inertial mass block are processed on the second substrate, and the beam structure is arranged on the third substrate. The first substrate, the second substrate and the third substrate are all made of double-polished super-flat silicon wafers, a single-mode optical fiber assembly is fixed to the optical fiber installation base, the end face of the single-mode optical fiber assembly is subjected to precise grinding and is perpendicular to the axial direction of an optical fiber core, and a first cavity mirror is formed by means of the end face of the side, facing the light through hole, of the inertial mass block. A second cavity mirror is formed on the end face of the single-mode optical fiber assembly, the first cavity mirror and the second cavity mirror form an F-P interference cavity, and the first substrate, the second substrate and the third substrate are connected through the silicon-silicon bonding technology.

Silicon photonics technologies adds integrated optics functionality to CMOS integrated circuits thereby leveraging high volume manufacturing. Independent of geometry or technology these silicon photonic devices require packaging with single mode optical fibers to interface to the optical network and / or co-packaging with active semiconductor devices, discrete microoptoelectromechanical systems (MOEMS) s or monolithically integrated MOEMS. Stringent performance constraints and minimizing manufacturing costs / times are consistent demands on such photonic circuits. Accordingly, there is a demand for low-cost and low-loss optical coupling technologies for packaging that can easily be scaled for mass production that overcome limitations in the prior art. The inventors have established design methodologies, packaging schemes and component designs that leverage automated passive assembly techniques for speed / cost in combination with directly written optical interconnects that allow for offsetting the losses that would arise from the manufacturing tolerances of these passive assembly techniques.

The invention relates to an all-fiber sub-hundred femtosecond laser based on an SESAM. The all-fiber sub-hundred femtosecond laser comprises the SESAM, a wavelength division multiplexer, a pumping source, a pumping protector, a gain fiber, a chirp fiber bragg grating, an isolator, a reflector, a compression unit and an autocorrelator. According to the invention, the chirp fiber bragg grating with the dispersion amount of 0.115 ps / nm is adopted to compensate positive dispersion in the cavity, so that mode-locked pulse with the spectral width of 23nm is realized. A transmission-type diffraction grating pair is adopted, the pulse width is compressed to 88fs, and the maximum spectral width 27nm is obtained under the dispersion of 0.00087 ps2 in a near-zero cavity. The condition that the optimal spectral bandwidth of the optimal seed source pulse based on the optical fiber chirped pulse amplification laser should be larger than 15 nm is met, and the compression pulse distortion of the amplifier is reduced. By adopting the linear cavity, the SESAM is adhered to the surface of the single-mode optical fiber patch cord for starting mode locking, so that an all-optical-fiber structure of the system is realized, and the single-mode optical fiber patch cord is suitable for industrial integrated application.

The invention belongs to the technical field of optical fiber sensing, and discloses a high-temperature-resistant and high-pressure-resistant multi-parameter integrated sensor and system based on optical fiber dislocation welding, and the sensor comprises a packaging main body, and the center of the packaging main body is provided with a center hole and a cavity which are used for accommodating a transmission optical fiber. The tail end of the transmission optical fiber is sequentially connected with a temperature detection device and a pressure / sound detection device which are positioned in the cavity; the temperature detection device comprises a fiber bragg grating; the pressure / sound detection device comprises a single-mode fiber, a multimode fiber, a first hollow capillary fiber and a second hollow capillary fiber which are connected in sequence; the axes of the first hollow capillary optical fiber and the second hollow capillary optical fiber are connected in a staggered manner to form an open structure. The pressure / sound-temperature multi-parameter composite in-situ synchronous measurement device realizes composite in-situ synchronous measurement of multiple parameters of pressure / sound-temperature, has the advantages of high temperature resistance, small size and high test precision, and has wide application prospects in the fields of aerospace, petroleum metallurgy, environmental monitoring and the like.

The invention relates to the technical field of optical fiber sensing, and provides a parallel double-cavity optical fiber copper ion sensor, which comprises an optical fiber coupler, a sensing Fabry-Perot interferometer and a reference Fabry-Perot interferometer, the sensing Fabry-Perot interferometer comprises a first single-mode fiber, a first capillary glass tube and hydrogel; one end of the first single-mode optical fiber is connected with the optical fiber coupler, and the other end of the first single-mode optical fiber extends into the first capillary glass tube; hydrogel is arranged on the end surfaces of the first single-mode optical fiber and the first capillary glass tube; the reference Fabry-Perot interferometer comprises a second single-mode fiber, a second capillary glass tube and a third single-mode fiber; one end of the second single-mode optical fiber is connected with the optical fiber coupler, and the other end of the second single-mode optical fiber extends into the second capillary glass tube; the third single-mode optical fiber also extends into the second capillary glass tube; and a gap is reserved between the third single-mode optical fiber and the second single-mode optical fiber. According to the invention, two reflection spectrums with small frequency difference are superposed to generate amplified frequency change, so that the sensitivity of copper ion measurement is improved.

The invention belongs to the technical field of deformation measurement, and provides a distributed optical fiber sensing casing damage monitoring system and monitoring method based on an OFDR (Optical Frequency Domain Reflectometer) technology. An armored optical cable consisting of a multi-core single-mode optical fiber and two multi-mode optical fibers of which the tail ends are welded into a U shape is spirally wound on the outer wall of a casing; a single-channel DSS / dual-channel DTS modulation-demodulation system of a dynamic distributed optical fiber strain and temperature composite sensing technology is used for real-time acquisition of strain and temperature sensing data of the casing pipe under the action of ground stress, and a cylindrical casing pipe three-dimensional model reconstruction algorithm is combined to automatically generate a spiral line. The three-dimensional model of the cylindrical casing is in one-to-one correspondence with the position of the optical fiber on the real casing, casing damage possibly occurring to the underground casing under the action of ground stress is monitored and measured in real time for a long time, early warning and forecasting information about that the casing damage is about to occur or is occurring is issued in time, and well site operators can conveniently handle and repair the casing damage in time.

The invention relates to an optical fiber communication sensing integrated architecture and a working method thereof. Comprising a sensing system laser, a coupler, a polarization beam splitter, a semiconductor optical amplifier, a polarization multiplexing communication transmitting system, a polarization wavelength two-dimensional demultiplexer, namely a WDM-PM device, a coarse wavelength division multiplexer MMI-WDM, a single-mode fiber, a polarization multiplexing communication receiving system, a polarization diversity double-balanced photoelectric detector PBPD, and an ROTDR and phi OTDR data processing unit. According to the invention, not only can high-capacity and long-distance communication under fusion of polarization multiplexing and wavelength division multiplexing be realized, but also sensing and communication can be fused through a wavelength division multiplexing system, the quality of sensing signals is improved through polarization diversity reception on the basis, and mutual promotion of communication and sensing is realized.

The invention discloses an optical fiber structure and system capable of simultaneously measuring curvature and temperature and a manufacturing method, and relates to the technical field of communication. The optical fiber structure capable of simultaneously measuring the curvature and the temperature is manufactured by forming a dislocation structure through the central axis of the single-mode optical fiber and connecting the dislocation structure with the optical fiber adapter, the optical fiber structure is simple in manufacturing process, stable in performance, low in price and high in precision, and the curvature sensitivity and the temperature sensitivity can be measured by demodulating the MZI wavelength sensitive to the temperature and the anti-resonance reflection waveguide strength. The problem of cross sensitivity of curvature and temperature is solved. Two different sensing mechanisms are combined, joint demodulation is carried out, and the device can be used for simultaneous sensing test of temperature and curvature.

The invention discloses a polarization-state-based optical fiber vibration sensing system and application, and relates to the technical field of optical fiber sensing, and the polarization-state-based optical fiber vibration sensing system mainly comprises a transmitting end and a receiving end. The transmitting end comprises a laser diode, a first erbium-doped optical fiber amplifier, a first circulator, a polarization scrambler, a single-mode optical fiber link, a second circulator and a second erbium-doped optical fiber amplifier which are connected in sequence; and the receiving end comprises a polarization beam splitter, a first shunt module, a second shunt module, an optical mixer, a first balanced photoelectric detector, a second balanced photoelectric detector, a third balanced photoelectric detector and a polarization analysis module. According to the optical fiber vibration sensing system based on the polarization state and the application, the vibration monitoring performance and reliability in a long-distance and high-noise environment can be improved.

The invention describes an apparatus that implements efficient coupling between a photonic integrated circuit (PIC) and a second optical element such as a fiber or laser, while at the same time allowing for efficient polarization management and / or optical isolation. It enables the packaging of PICs with large single mode fiber counts and in- and out-coupling of light with arbitrary polarization. The apparatus comprises a glass interposer that contains at least one polarization selective element together with a pair of lenses transforming a beam profile between the 2nd optical element and a polarization selective coupler on the PIC. The invention also comprises a method for fabricating the apparatus based on a subassembly of building blocks that are manufactured using wafer-scale high-precision glass-molding and surface treatment(s) such as thin-film coating.

The invention discloses a photonic integrated circuit chip and a silicon optical integration platform, and aims to provide a specific waveguide structure on the photonic integrated circuit chip to realize efficient coupling with a common single-mode fiber, and meanwhile, a suspended structure is not introduced, so that the overall structure has relatively high mechanical stability. The method can pass high-temperature and high-humidity reliability test conditions of the photon integrated circuit chip, and is compatible with reflow soldering, silicon through hole and other processes.

The invention discloses an ultrahigh resolution interferometer measurement method and system based on a phase shift gauge block, and the method comprises the steps: placing an ultrahigh resolution interferometer and a preset phase gauge block in a heat preservation box, and introducing two kinds of frequency stabilization laser into the heat preservation box through a single-mode optical fiber; obtaining interference fringe data by adopting a five-step phase shift method, and adjusting the interference fringe data according to the laser wavelength to obtain adjusted data; acquiring environmental data containing the preset phasor block in the heat preservation box, and correcting the adjustment data by eliminating change influence based on the environmental data to obtain corrected data; determining the length of the preset phasor block according to the decimal number of the interference fringes and the integer series of the interference fringes under different wavelengths through a multi-wavelength decimal superposition method, obtaining the measurement data of the Korotkoff interferometer, carrying out the adaptive compensation of the phase shifter, correcting the length according to the uncertainty of the measurement data, and obtaining the phase of the Korotkoff interferometer. The output is a measurement result.

The invention discloses a photoacoustic focusable endoscopic imaging device based on temperature control memory alloy and an imaging method. The photoacoustic focusable endoscopic imaging device comprises a bidirectional memory metal photoacoustic zoom module, the bidirectional memory metal optical-acoustic zoom module comprises an optical fiber fixing clamp, a gradient refractive index lens, a light-reflecting and sound-reflecting mirror, a transducer, a temperature control memory alloy spring and a temperature control deformation current controller, the optical fiber fixing clamp is used for clamping an optical fiber outer sleeve, and the bidirectional memory alloy spring is connected with the optical fiber fixing clamp; the optical fiber outer sleeve and the single-mode optical fiber penetrate through the center of the temperature control memory alloy spring, and the temperature control memory alloy spring can be controlled to deform through the temperature control deformation current controller, so that the position of the single-mode optical fiber relative to the gradual change refractive index lens is changed. By applying the temperature control memory alloy spring to photoacoustic endoscopy, dynamic infinitesimal displacement of an optical device is realized based on the characteristic that the temperature control memory alloy spring deforms differently at different temperatures, so that dynamic focusing is realized, and the limitation of depth of field is overcome.

The invention discloses a diaphragm type EFPI optical fiber sonic sensor with a sensibilization structure, and relates to the field of optical fiber sensing and underwater acoustic signal communication. The sensor is composed of an optical fiber unit, a threaded sleeve and a sensitization shell which are connected in sequence. The single-mode optical fiber is embedded into the optical fiber ceramic ferrule as a first reflecting surface and inserted into the threaded sleeve in a combined manner, and the chromium-gold composite film is attached to the outer side of the threaded sleeve as a second reflecting surface through epoxy resin glue; the sensitization shell is combined with the threaded sleeve in a screwed mode, the chromium-gold composite film is protected, sound signals are gathered, and the sensitization effect is achieved. The invention has the following advantages and positive effects: (1) the FZP sensitization structure improves the minimum detectable sound pressure of the hydrophone and enhances the capability of identifying weak small signals; (2) the designed water pressure balance hole contributes to the water pressure in the F-P cavity and the outside, and can be suitable for deepwater operation; and (3) the nano-scale transduction film of the film type EFPI sensor can be protected to a certain extent, and the film type EFPI sensor can be suitable for changing environments.

The invention discloses a fiber bragg grating femtosecond laser direct writing system and method based on light field regulation and control. The system comprises a femtosecond laser source, a polarization control module, a light beam expanding module, a light field modulation module, a 4f filtering imaging module, an oil immersed objective lens, a precision positioning and optical fiber clamping module, an observation module and a computer control module. The method comprises the following steps: firstly, fixing a standard single-mode optical fiber to be processed on a three-dimensional precision displacement platform; then programmable wavefront modulation is carried out on the femtosecond laser through a light field modulation module, and a multi-focus array is generated; then focusing the multi-focus array into the fiber core through an oil-immersed objective lens to realize one-time parallel inscribing of a plurality of refractive index modulation RIM regions; and finally, the computer control module controls the three-dimensional precision displacement platform to move at a constant speed in the axial direction of the optical fiber, and parallel integrated inscribing of a plurality of FBG structures is completed. According to the invention, the inscribing precision and inscribing efficiency of fiber bragg grating femtosecond laser direct writing are improved.

The invention discloses a multi-parameter C4F7N gas detection optical fiber Fabry-Perot sensor with a temperature compensation function, belongs to the technical field of C4F7N gas detection, and solves the problems that an existing optical fiber sensing instrument is low in sensitivity and single in application scene. When the sensor is in an environment with target gas, a detection result of the environment gas and a detection result of the temperature can be obtained, so that the application range of the sensor is widened; the gap between the end face of the single-mode fiber and the surface of the groove forms a Fabry-Perot cavity, emergent light of the single-mode fiber is reflected by the surface of the groove, the groove converges the reflected light, the reflectivity is improved, the reflected light is efficiently coupled into the single-mode fiber, the contrast ratio of a light interference peak is improved, and then the detection sensitivity of the sensor is improved. The sensor is simple in structure, small in size, high in reliability and capable of achieving high-sensitivity measurement of the C4F7N gas decomposition products.

The invention discloses an integrated optical diversity receiving device, solves the problem of high power consumption when the influence caused by phase distortion and light beam pointing error is corrected in the existing free space optical communication, and belongs to the field of optical communication. The method comprises the steps that free space light focused by a lens is received by a multimode / few-mode optical fiber; the multi-mode light beams received by the multimode / few-mode optical fiber enter the photon lantern; the photon lantern is coupled to the single-mode fiber array after mode demultiplexing; each light beam in the single-mode fiber array enters a polarization beam splitting rotary combiner through an edge coupler; the polarization beam splitting rotation combiner performs transverse electric wave (TE) and transverse magnetic wave (TM) mode separation on the entered light beam, then rotates the separated TM polarization state light to a TE polarization state, combines the rotated TE polarization state light and the separated TE polarization state light, and then enters the MZI network; the MZI network is used for realizing optical coherent beam combination; a control circuit controls the merging of the light beams in the MZI network.

The invention discloses a method of an optical anti-turbulence device for polarization multiplexing spatial optical communication. The mode demultiplexer is connected with the optical fiber; the single-mode optical fiber array is respectively coupled with each spatial intrinsic mode decomposed by the mode demultiplexer; the polarization CBC chip is connected with the other end of the single-mode optical fiber array; the driving control module is connected with the polarization CBC chip; the polarization multiplexing optical communication digital coherent receiver (Rx) is connected with the polarization CBC chip through a single-mode optical fiber; through the arrangement of the polarization CBC chip, the compatibility of a polarization multiplexing technology and a mode multiplexing coherent beam combination technology is realized, the problem of polarization dimension information loss or strong crosstalk caused by the use of a polarization state rotator (PSR) and a polarization maintaining optical fiber in the prior art is solved, modulation information of two orthogonal polarization dimensions is completely reserved, the communication bandwidth is improved, and the communication efficiency is improved. And the communication efficiency is greatly improved.

The present invention discloses a magnetic field and temperature sensor of a metallized fiber grating cascade F-P structure, comprising a laser light source (1), an optical fiber circulator (2), a sensing probe (3), a first signal processing module (4), and a second signal processing module (5), wherein the sensing probe (3) comprises an optical fiber grating (3-1), an aluminum metal film (3-2), a magnetic fluid (3-3), a capillary glass tube (3-4), an epoxy resin (3-5), and a single-mode optical fiber (3-6); the optical fiber grating and the single-mode optical fiber are axially aligned and arranged at a micrometer interval in the capillary glass tube to form an F-P cavity; the F-P cavity filled with magnetic fluid utilizes the adjustable refractive index characteristics of the magnetic fluid to change the equivalent cavity length of the F-P cavity, thereby realizing magnetic field measurement; the metallized optical fiber grating utilizes the grating thermal expansion effect and the increased sensitivity of the metal film to change the grating period, thereby realizing temperature measurement; and the double parameter measurement of magnetic field and temperature is realized by measuring the drift of the reflection spectrum and the transmission spectrum.

The invention relates to a combined optical fiber and a preparation method, and relates to the technical field of optical fiber preparation, and the combined optical fiber comprises an anti-resonance hollow-core optical fiber having a first mode field diameter; the single-mode optical fiber has a second mode field diameter, and the first mode field diameter is larger than the second mode field diameter; one end of the bridging optical fiber is connected with the anti-resonance hollow-core optical fiber and is matched with the mode field of the anti-resonance hollow-core optical fiber, and the other end of the bridging optical fiber is connected with the single-mode optical fiber and is matched with the mode field of the single-mode optical fiber. The anti-resonance hollow-core optical fiber and the single-mode optical fiber are connected through the bridging optical fiber, and the two ends of the bridging optical fiber are matched with the anti-resonance hollow-core optical fiber and the single-mode optical fiber respectively, so that compared with a direct fused biconical taper single-mode optical fiber, the bridging optical fiber is lower in operation difficulty, better in connection performance and capable of being replaced even if misoperation occurs, and the combined optical fiber is convenient to prepare; the problem that in the prior art, a combined optical fiber with an anti-resonance hollow-core optical fiber is difficult to prepare conveniently is solved.

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 the technical field of optical communication, in particular to a hollow-core optical fiber and single-mode optical fiber coupling structure and a coupling method thereof.On one hand, a light converging part is arranged through corrosion, then the light converging part is inserted into a coupling pipe, operation is easy, accuracy is high, insertion core corrosion can be conducted in batches, production is facilitated, and through non-insertion type coupling, the coupling efficiency is improved; the coupling structure can be suitable for hollow-core optical fibers with various fiber core sizes, has lower connection loss and higher coupling efficiency, has higher flexibility and compatibility in the aspect of connection between the hollow-core optical fibers and other optical fibers, and is not easily influenced by external interference and environment; and on the other hand, by controlling the distance between the light converging part on the optical fiber coupling section and the joint of the coupling tube and the hollow-core optical fiber, the situation that reflected light enters the hollow-core optical fiber can be reduced, echo reflection is reduced, and therefore the transmission effect of optical signals is improved.

The invention discloses an optical fiber probe imaging catheter module for an intravascular frequency domain OCT (optical coherence tomography) imaging system, which comprises a transparent protective sleeve and a lining tube arranged in the transparent protective sleeve, a transparent window is arranged at the front end of the transparent protective sleeve, and a single-mode optical fiber, a coreless optical fiber, a GRIN (gradient refractive index) lens and a reflector are sequentially arranged in the lining tube. And a torsion spring tube is arranged outside the single-mode optical fiber. The design of the optical fiber probe and the double-layer catheter is optimized, the imaging resolution is improved, the adaptability of the probe and tissue is enhanced, the optical signal transmission efficiency is improved, high-resolution and low-friction intravascular imaging is provided, and the OCT image quality and reliability are improved.

The invention discloses an integrated optical fiber ultrasonic endoscope and a preparation method, and belongs to the field of ultrasonic sensors. Comprising a multi-core optical fiber, a dielectric film, a strip-shaped sensing layer, a mixed excitation inclined wedge, a sensibilization column and an endoscopic sheath. Double sensibilization is achieved through the sensibilization columns and the strip-shaped sensing layer, the sensitivity of lateral sensing is greatly improved, and good directivity is achieved on a film layer plane through the strip-shaped structure of the sensing layer. And the mixed excitation inclined wedges respectively realize side sound field excitation which is double and quadruple of that of the traditional single-mode optical fiber in two intensity directions. The problems that an existing optical fiber ultrasonic sensor is large in size, low in excitation power, low in integration level and low in sensitivity are solved.

The invention belongs to the technical field of pavement monitoring methods, and particularly discloses a distributed optical fiber permanent deformation monitoring method for an asphalt pavement under a moving load. The method comprises the following steps: laying a single-mode optical fiber in a test piece; laying a full-bridge strain gauge in the test piece; monitoring an optical fiber vibration signal of the test piece during the movement of a test wheel and a strain change of the test piece during the movement of the test wheel in real time through a strain acquisition instrument; processing the optical fiber vibration signal and the strain change by using matlab data analysis software; analyzing the data change trend according to the processed optical fiber vibration signal and the strain change, and establishing a mathematical relationship between the two; and according to the mathematical relationship, distributed monitoring of the permanent deformation of the asphalt pavement under the moving load by the optical fiber vibration signals is realized. By the adoption of the bituminous pavement distributed optical fiber permanent deformation monitoring method under the moving load, real-time, dynamic, large-range, long-distance and high-precision monitoring of bituminous pavement permanent deformation is achieved, and the defects in the prior art are overcome.

The invention discloses an optical fiber ocean temperature-salinity-depth multi-parameter integrated sensor based on accumulated optical fiber length sensitization, which is characterized by comprising a cabin cover penetrating module, a depth measurement module, a temperature mode measurement block and a salinity measurement module which are sequentially connected through single-mode optical fibers along the direction from signal input to signal output, the cabin penetrating cover body module comprises a sensor top cover and an optical fiber cabin penetrating joint; the depth measurement module comprises an inner layer protection shell, a deep sensitive optical fiber ring, a depth transduction disc and seawater; the temperature measurement module comprises heat conduction oil, a temperature-sensitive optical fiber ring and a temperature transduction mandrel; the salinity measurement module comprises an outer-layer protective shell, an outer-layer hollow structure, a salt-sensitive optical fiber structure and an inner-layer mandrel structure. The temperature-salinity-depth sensor has the beneficial effects that a temperature-salinity-depth sensing model in which a plurality of parameters are measured by one optical fiber is established, and the problems of low universality, low sampling rate, low integration, poor long-term stability and the like of a temperature-salinity-depth instrument are solved.