141 results about "Fiber loop" patented technology

The invention relates to a self-coherence optical fiber interference device and method for simultaneously measuring morphology and thickness. The device comprises a light source module (1), a measurement light path (2), a compensation light path (3), a spectrograph (4), a mechanical motion module (6) and a data processing module (5), the measuring light path (2) comprises an optical fiber circulator (21), an optical fiber retroreflector (22) and an optical probe (23) and is used for realizing focusing measurement and enabling reflected light of the end face of the optical fiber retroreflector (22) and reflected light of a transparent object to be measured to return; reflected light of the end face of the optical fiber retroreflector (2) and reflected light of the transparent object to be measured form a measuring light beam, and the measuring light beam enters the compensation light path (3); the compensation light path (3) comprises an optical fiber splitter (31), an optical fiber delay line (32) and an optical fiber coupler (33), the measuring light beam is subjected to optical path compensation to generate a compensation light beam, and the compensation light beam and the measuring light beam are combined and input into the spectrograph (4) together.

The embodiment of the invention discloses an intrinsic frequency on-line adjusting system and method, a parameter adjusting method, equipment and a medium, and the device comprises at least one electromagnetic coil, an electromagnetic coil drive circuit, an optical fiber loop and a light beam processing module. The electromagnetic coil driving circuit is electrically connected with the electromagnetic coil and is used for providing target driving current for the electromagnetic coil so as to change the magnetic field of the electromagnetic coil through the target driving current; the electromagnetic coil is used for adjusting the refractive index of the optical fiber loop through a generated magnetic field; the optical fiber loop penetrates through the at least one electromagnetic coil, and the tail ends of extension branches at the two ends of the optical fiber loop are connected with the light beam processing module and used for maintaining the target eigenfrequency of the target equipment based on the current refractive index. According to the technical scheme provided by the embodiment of the invention, the on-line adjustment of the eigenfrequency of the optical fiber ring can be realized in a full-temperature range, so that the environmental adaptability of equipment is improved.

The invention provides a gas saturation absorption optical path structure based on dual optical path enhancement, which belongs to the field of laser optical path design and comprises an optical fiber circulator, a gas absorption chamber and an optical fiber reflector. A first port of the optical fiber circulator is connected with a laser output optical fiber, a second port of the optical fiber circulator is connected with an input collimator of the gas absorption chamber, and a third port of the optical fiber circulator is connected with a detector and is used for providing frequency reference for gas absorption; and the optical fiber reflector is connected with the output end of the gas absorption chamber. According to the invention, the physical contradiction between the air chamber size and the optical path gain is broken through, and a compact frequency stabilization system with miniaturization and high stability is realized.

The invention relates to the technical field of optical fiber fault detection, in particular to a health monitoring system and method for a water diversion engineering optical fiber network, and the system comprises a sensing module which is used for synchronously collecting optical fiber environment parameters through an edge calculation node and a multi-source sensor array; the transmission network construction module is used for carrying out short-distance networking and constructing a backbone transmission network by adopting an industrial grade PON (Passive Optical Network) optical fiber network; the cloud management platform is used for preprocessing the data acquired by the transmission network construction module; inputting the preprocessed data into a preset D-S evidence theory fusion model to obtain an early warning trigger signal; and the fault classification module is also used for carrying out fault positioning and classification through the trained fault classification model after the edge node detects an abnormal signal, and outputting a fault position and a fault type. According to the invention, the problems of insufficient real-time performance and incapability of dealing with sudden faults in the prior art can be solved; the positioning precision and the fault identification capability are limited; the long-distance deployment cost is high; and the management complexity is high.

A loop pigtail compensation method for a fiber-optic gyroscope, and a fiber length compensator. The fiber length compensator is fixed on a loop pigtail of the fiber-optic gyroscope, and the fiber length compensator includes a peripheral fiber loop and an expansion-and-contraction shaft core capable of realizing deformation of expanding and contracting; and upon detecting that there is a drift in an output of the fiber-optic gyroscope, a length of the peripheral fiber loop of the fiber length compensator is changed by adjusting a coefficient of linear expansion of the expansion-and-contraction shaft core of the fiber length compensator, so that the compensation for the loop pigtail of the fiber-optic gyroscope is realized, and the problem of low accuracy of online adjustment of the pigtail of the fiber-optic gyroscope is solved.

The invention belongs to the technical field of optical fiber sensing, and discloses a static ice pressure and temperature compensation sensor based on a double-optical-fiber annular ring-down cavity, which comprises a cavity substrate, an H-shaped base is arranged on the bottom surface of the cavity substrate, a first long groove and a second long groove are respectively formed in the upper surface and the lower surface of the H-shaped base, a first optical fiber is arranged in the first long groove, and a second optical fiber is arranged in the second long groove; the upper surface of the cavity substrate is provided with an elastic membrane used for sealing the cavity, the bottom of the elastic membrane is provided with a protrusion, the first optical fiber and the second optical fiber are provided with a first fiber bragg grating and a second fiber bragg grating respectively, the first fiber bragg grating is fixedly connected with the protrusion, and the second fiber bragg grating is fixedly connected with the protrusion. The second fiber bragg grating is fixedly connected with the second long groove; two ends of the first optical fiber and the second optical fiber are led out from two ends of the cavity substrate and then are respectively connected with an optical fiber annular ring-down cavity. According to the invention, the static ice pressure sensing precision can be improved.

The utility model provides a kind of optical fiber optical tweezers fluorescence lifetime detection equipment, by the light beam emitted by light source is divided into two ways, using the first optical fiber coupler to the two-way light signal received is coupled, and the light signal after coupling is transmitted to the optical fiber circulator connected, transmission to displacement control assembly by optical fiber circulator. Displacement control assembly utilizes one-way light signal to carry out target micro-particle capture, utilizes another light beam corresponding light signal to excite target micro-particle to generate excitation fluorescence signal, utilizes detection assembly to carry out photon number detection to excitation fluorescence signal, determines the fluorescence lifetime of target micro-particle. The utility model equipment can be realized in flexible control micro-particle, and the fluorescence lifetime of micro-particle is detected, and the utility model is more simple and efficient, applicable to precision large instrument to carry out ultrafast signal detection.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

This invention discloses a 9-cavity mode-locked fiber laser with adjustable parameters based on a liquid crystal phase delay device, belonging to the field of mode-locked laser technology. It includes, along the optical path, a mirror, a polarizing beam splitter prism, a liquid crystal phase delay adjustable waveplate, a Faraday rotator, a liquid crystal phase delay adjustable waveplate, and a polarizing beam splitter prism. A fiber optic loop is provided on one side of the polarizing beam splitter prism, comprising, in sequence, a fiber collimator, a gain fiber, a wavelength division multiplexing-splitter mixer, and a fiber collimator prism. The slow axis of the fiber collimator prism's pigtail is aligned horizontally with the polarizing beam splitter prism prism 2; the slow axis of the fiber collimator prism 2's pigtail is aligned vertically with the polarizing beam splitter prism prism 2. A pump semiconductor laser is connected to the pump input of the wavelength division multiplexing-splitter mixer, and an FCAPC jumper is connected to the signal output of the wavelength division multiplexing-splitter mixer. This enables continuous and rapid adjustment of the laser parameters.

The utility model relates to a central air-conditioning monitoring system for a high-speed rail station, which comprises a monitoring host and a cold and heat source host PLC master station connected with the monitoring host, and the cold and heat source host PLC master station is accessed to the monitoring host through network cable jump. The tail end sensor is arranged in an air conditioner fan box, is connected to the DDC control cabinet, and is in signal connection with the monitoring host through a BAS optical fiber ring network of a station; the environment monitoring sensor comprises an environment parameter integrated monitor installed in a waiting room and a fuel gas monitor installed in a heating and ventilation power machine room, and the environment monitoring sensor is in signal connection with the monitoring host through a BAS optical fiber ring network of a station. Compared with the prior art, the cold and heat source host, the terminal air-conditioning box of the waiting room and the monitoring sensor of the waiting room environment are connected to the monitoring host of the elimination control room through the station local area network, so that information such as the running state of the central air-conditioning system, the temperature and humidity of the outdoor environment, the heat and humidity state of the terminal air-conditioning box and the like can be obtained; management personnel can conveniently know the environment in the station and the running state of the central air conditioner.

This application provides an optical fiber sensing system, its calibration method, and a storage medium, relating to the field of optical fiber sensing technology, to improve the dynamic range of the optical fiber sensing system. The optical fiber sensing system includes a signal generator, an optical fiber circulator, a reference optical fiber, a single-photon detector, a processor, and a sensing optical fiber. The signal generator, reference optical fiber, and single-photon detector are respectively connected to the optical fiber circulator. The sensing optical fiber is connected to the reference optical fiber. The single-photon detector is used to acquire a first reference measurement signal and a second reference measurement signal. The first reference measurement signal has attenuation compared to the second reference measurement signal. The processor is used to determine a dead time based on the first reference measurement signal, the second reference measurement signal, and the attenuation coefficient corresponding to the attenuation. The single-photon detector is also used to acquire sensing measurement signals. The processor is also used to calibrate the sensing measurement signals based on the dead time. This optical fiber sensing system is used to detect the state of a target.

The application provides a distributed optical fiber acoustic wave sensing system and a pattern recognition method. The application relates to the fields of optical fiber sensing and pattern recognition, and the system comprises the following steps: continuous coherent light emitted by a narrow-line-width laser is split into two paths by a beam splitting fiber coupler, one path is used as local reference light, and the other path is used as probe light; the probe light is modulated into optical pulses in an acousto-optic modulator driven by a waveform generator, and the optical pulses are injected into a measured sensing optical fiber through a fiber loop; Rayleigh backscattering light returned through the measured sensing optical fiber is mixed with the local reference light through the fiber loop, and the mixed light is decomposed into two orthogonal polarized light beams in a polarization beam splitter and is transmitted to a first balanced photodetector and a second balanced photodetector respectively to be converted into electrical signals; and the two orthogonal interference electrical signals are synchronously collected by a data acquisition card and are sent to a host computer for demodulation. The application provides a new distributed acoustic wave monitoring method with high reliability and high generalization ability, and has extremely high engineering popularization value.

The invention discloses a photon neural network based on a time synthesis dimension and a training method thereof, and the photon neural network comprises a light input module which is used for generating a square wave light pulse; the light processing module is connected with the output end of the light input module and is used for regulating and controlling the amplitude and the phase of the square wave light pulse; the optical processing module is arranged based on a coupling optical fiber loop architecture, and an optical path is split into long and short optical fiber loops which are coupled with each other through a variable beam splitter, so that propagation paths of square wave optical pulses in the long and short optical fiber loops equivalently form time synthesis photonic crystals; and the light output module is connected with the output end of the light processing module and is used for detecting the light intensity of the square wave light pulse when the square wave light pulse is propagated in the light processing module. Wherein the optical processing module can be replaced by an integrated photonic chip architecture arrangement, and the optical processing module enables propagation paths of square wave optical pulses in long and short waveguide loops to equivalently form time synthesis photonic crystals through the long and short waveguide loops which are mutually coupled by a 50: 50 beam splitter.

The invention discloses a coherent optical frequency signal regeneration amplification system based on optical fiber transmission. The coherent optical frequency signal regeneration amplification system comprises a local narrow linewidth laser which outputs narrow linewidth laser; the first optical fiber coupler couples the narrow linewidth laser to the first acoustic optical modulator and the second acoustic optical modulator respectively; the output of the first acousto-optic modulator and superior transmission light are jointly coupled into a photoelectric detector by a second optical fiber coupler to generate a beat frequency signal; the signal processing module samples the beat frequency signal after conditioning the beat frequency signal, performs phase discrimination on the sampled signal and the digital reference signal to generate an error signal, and generates a first feedback signal and a second feedback signal according to the error signal to be respectively used by the local narrow linewidth laser and the first acousto-optic modulator; performing real-time cycle slip detection on the error signal and repairing a phase abnormal point to generate a third feedback signal to be used by a second acousto-optic modulator; and the second acousto-optic modulator outputs amplified regenerated laser. According to the invention, high-precision optical frequency signal transmission can be realized in a complex and changeable optical fiber environment with large noise.

The application discloses a hydropower station network reconstruction method based on a redundancy technology, which comprises the following steps: upgrading an internal control network of a hydropower station into a hundred-megabit redundant fiber ring network and configuring an MRP sub-ring redundancy protocol; establishing a Hiper-Ring gigabit redundant fiber ring network between watersheds of cascade hydropower stations and starting three-layer routing function and VRRP function; using Hesmann three-layer switches for data transmission between a remote control center and the hydropower station; adopting a link aggregation technology to add a two-layer aggregation device between a dam LCU switch and a watershed switch RSPE30; and performing function test. The hydropower station network reconstruction method based on the redundancy technology provided by the application adheres to the principles of openness, expansibility, reliability and investment saving, eliminates existing problems based on the existing network, does not affect the operation of the network that has been put into use during later network access reconstruction, combines industrial control technology with IT technology, and provides a redundant, reliable and efficient automatic control communication network for a computer monitoring system of the hydropower station.

An optical fiber loopback assembly includes a fiber optic connector and a loopback shell coupled to a boot of the fiber optic connector. The fiber optic connector can be a known connector, thereby avoiding the need for specialized components or modifications. The loopback shell includes a portion behind the boot of the connector, but can have a compact design that is still configured to store excess length of loopback optical fibers.

The invention discloses an optical interface structure of an integrated photonic chip for a fiber-optic gyroscope and an optical coupling method, and belongs to the technical field of integrated optics and optical fiber sensing. All input and output ports of the integrated photon chip are arranged on a coupling end face on the same side of the chip, the ports comprise at least two signal ports and two auxiliary ports, the signal ports are used for connecting tail fibers of polarization maintaining fiber rings of all measuring axes of the fiber-optic gyroscope, and the auxiliary ports are connected with a through type auxiliary coupling optical channel in the chip; each port is integrated with a spot size adaptation unit, and the spot size adaptation unit is used for matching the spot size of the polarization maintaining optical fiber and the chip waveguide; the integrated photon chip realizes single-side end face alignment coupling with the multi-channel polarization-maintaining optical fiber array through the coupling end face, tail fibers of polarization-maintaining optical fiber rings of all measuring axes of the optical fiber gyroscope are directly solidified in the multi-channel polarization-maintaining optical fiber array, a head channel and a tail channel of the multi-channel polarization-maintaining optical fiber array are aligned with two auxiliary ports of the chip respectively, and no extra welding link is needed. According to the invention, the problems of dispersed channel-by-channel coupling of optical interfaces, complex alignment of two-side FAs, large dual-link coupling loss, serious polarization cross coupling and uncontrollable coupling quality are solved, the overall precision and environmental stability of the fiber-optic gyroscope are remarkably improved, the method is suitable for various fiber-optic gyroscopes with single axes, multiple axes and the like, and the system integration level and the assembly consistency are remarkably improved.

The application discloses a kind of induction logging instrument systems and acquisition method based on plasma optical fiber sensor, including ground current emission source and at least one well in current emission source and well in receiving acquisition device, the well in receiving acquisition device is connected with the optical system of induction signal detection being arranged on ground, the optical system is composed of sequentially connected broadband light source, polarizer, polarization controller, fiber optic circulator and spectrum analyzer, the fiber optic circulator is connected with well in receiving acquisition device and spectrum analyzer respectively, at least two plasma resonance optical fiber sensing probes are arranged in the well in receiving acquisition device. There is no mutual interference or crosstalk between plasma resonance optical fiber sensor, optical fiber sensor and emission power supply and antenna, and it is not easy to be disturbed by environmental electromagnetic noise, and multi-channel large data high-speed real-time transmission can be realized by using armored photoelectric composite cable connected with each well in receiving acquisition device.

The utility model provides a cable searching monitoring device integrating accurate positioning of optical fibers and cables and beforehand perception of environment situations, which comprises a multi-wavelength light source, a first multi-wavelength WDM coupler, a first photoelectric detector, a second photoelectric detector, a third photoelectric detector and an optical fiber loop to be detected, and the first multi-wavelength WDM coupler is provided with a first beam splitting and combining unit and a second beam splitting and combining unit. The output end of the second beam splitting and combining unit is connected with the third photoelectric detector, the first beam splitting and combining unit is connected with the first photoelectric detector and the second photoelectric detector, the optical fiber loop to be detected is connected with the first beam splitting and combining unit and the second beam splitting and combining unit in series, and the optical fiber loop to be detected is provided with a port A and a port B; the first beam splitting and combining unit is provided with a first Sagnac interference structure, a first light path and a second light path. The optical cable external vibration sensing and positioning device has the advantages that the low-cost Sagnac interference technology principle is adopted, the optical cable external vibration sensing and positioning device with the over 200 km performance of the ring topology is achieved, multiple functions are integrated, the convenience of a system can be greatly facilitated, the cost performance is high, and large-scale popularization is facilitated.

A transformer internal partial discharge positioning method based on an optical fiber sensing array, comprising: processing a triangular ultrasonic sensing array, wherein the triangular ultrasonic sensing array comprises: at least 3 optical fiber Fabry-Perot sensors; connecting the output end of a wavelength tunable laser to a 1*3 optical fiber coupler, and connecting 3 optical fibers from the 1*3 optical fiber coupler to 3 optical fiber circulators respectively; connecting the 3 optical fiber circulators to the optical fiber Fabry-Perot sensors, and connecting the 3 optical fiber circulators to 3 photodetectors respectively; connecting the output ends of the 3 photodetectors to the input ends of a signal acquisition card, storing signal data, storing the data in the signal acquisition card into a computer; carrying out wavelet threshold denoising on the collected signal data; using a generalized cross-correlation function on the denoised signal data to extract time delay information; and using an artificial firefly and clustering analysis joint optimization algorithm to solve the accurate position of the partial discharge source according to the obtained time delay information.

The invention relates to the technical field of electric data digital processing, in particular to an optical fiber distributed sensing signal identification method and system with a low false drop rate, and the method comprises the following steps: S1, collecting vibration signal data of a sensing optical fiber through a distributed vibration sensing system, and carrying out the preprocessing of the vibration signal data to obtain a vibration signal data set; s2, an improved YOLOv9 network model is built; s3, dividing the collected vibration signal data set into a training set, a verification set and a test set, and performing iterative training on the improved YOLOv9 network model by using the training set until the model converges to obtain a trained improved YOLOv9 network model; and S4, inputting vibration signal data acquired in real time into the trained improved YOLOv9 network model, and performing forward propagation reasoning recognition prediction to obtain a recognition result containing category information and position information of the target. According to the method, the cross-scale target feature expression capability of the network is remarkably improved, the false detection probability in a complex scene is effectively reduced, and the application requirement of cross-scale target detection in an optical fiber environment is practically met.

The invention discloses an optical fiber collimator, isolator and circulator in an orbital angular momentum mode, and belongs to the field of optoelectronic communication devices. Based on a special optical fiber collimator design scheme, the OAM optical fiber collimator which is simple in structure and excellent in performance is realized. On the basis of an OAM optical fiber collimator, an isolation core and an annular core are combined, and an OAM optical fiber isolator and an OAM optical fiber circulator which are low in cost, low in processing complexity, small in occupied size and excellent in performance are respectively realized through a special packaging process. The isolator and the circulator have the characteristics of low insertion loss, high isolation degree, high quality of a transmitted OAM mode and the like. The OAM optical fiber collimator, isolator and circulator realized by the invention can replace free space optical devices with consistent functions in systems such as an OAM mode optical fiber communication system, an OAM optical fiber amplifier and the like. The cost of the mode division multiplexing optical fiber communication system based on the OAM mode is reduced, the flexibility of the system is improved, and the method has important significance for promoting the practicability and miniaturization of the optical fiber communication system.

This invention discloses a fiber optic deformation sensor and deformation measurement method based on Sagnac interferometry. The sensor includes a Sagnac interferometer optical path and a photoelectric conversion module. The Sagnac interferometer optical path includes a sensing fiber loop, which includes at least one segment of polarization-maintaining fiber. The polarization-maintaining fiber has an axially stretchable elastic helical structure. The interference light intensity output by the Sagnac interferometer optical path changes monotonically with the axial stretch of the polarization-maintaining fiber. The photoelectric conversion module receives the interference light intensity and converts it into an electrical signal. This invention achieves wide-range deformation measurement while maintaining high sensitivity by setting the polarization-maintaining fiber as an axially stretchable elastic helical structure. It uses an intensity modulation method to directly convert the signal into an electrical signal through a photodetector, eliminating the need for a spectrometer, significantly reducing system cost. Furthermore, the structure is simple and easy to fabricate, making it widely applicable to various high-precision, large-deformation real-time monitoring scenarios.

The invention belongs to the technical field of sound wave measurement, and particularly relates to an array type sensing system based on an optical resonant cavity, which comprises a laser light source, an optical switch device, a light splitting path optical device, the optical resonant cavity and a negative feedback module, the optical path splitting optical device comprises an optical fiber beam splitter, an optical path splitting delay line, an optical fiber circulator and a coupling device; the negative feedback module is connected with the optical fiber circulator and the laser light source; the laser light source emits laser beams, light pulses are generated through the optical switch device and equally divided into a plurality of split light beams through an optical fiber beam splitter in the light-path-splitting optical device, each split light beam enters the optical resonant cavity after being sequentially coupled through the light-path-splitting delay line, the optical fiber circulator and the coupling device, the optical resonant cavity reflects the split light beams along an original light path, and the light-path-splitting optical device outputs the reflected light beams. The reflected split light beams are coupled to the coupling device and then transmitted to the negative feedback module through the optical fiber circulator, and the negative feedback module processes split light beam signals reflected by the optical fiber circulator and then inputs the split light beam signals to the laser light source for compensation of the laser beams.

The application provides a fiber ring temperature performance testing device, which comprises a high-low temperature box and a constant temperature box. The high-low temperature box is internally provided with a rotatable first turntable, and the constant temperature box is internally provided with a rotatable second turntable. The second turntable is used for placing a test host. A transmission central shaft assembly is connected between the first turntable and the second turntable, so that the first turntable and the second turntable synchronously rotate. The first turntable is provided with a fiber ring support, and the fiber ring support is used for placing a measured fiber ring. The first turntable is further provided with an isolation cover for buckling the measured fiber ring. The problem that the test system itself is affected by temperature and is wound dry, thereby affecting the test precision, is solved.

The application belongs to the technical field of optical fiber gas sensing, and discloses a kind of optical fiber photoacoustic gas sensing system and method suitable for low pressure environment.System includes programmable logic gate array circuit, distributed feedback laser, laser transmission optical fiber, optical fiber photoacoustic sensing probe, super radiation emitting diode light source, optical fiber circulator and spectrometer.According to the linear relationship between the cantilever beam resonance frequency and the ambient pressure, the gas pressure is monitored, and the acoustic sensitivity at the resonance of the cantilever beam is enhanced at low pressure to compensate for the attenuation of the signal in the photoacoustic excitation process.Combined with the measured pressure of the cantilever beam, the sensitivity is corrected, so as to realize the high precision and high sensitivity detection of trace gas under low pressure environment.The system only uses a single cantilever beam and a single demodulator, and has the functions of pressure and gas concentration detection, and can realize accurate detection of trace gas in a changing pressure environment.The all-fiber scheme has the characteristics of intrinsic safety, and is easy to remote measure and multi-point network detection.

The invention discloses an optical transmission system, an optical fiber loop system and electronic equipment, and relates to the technical field of optical transmission, and the optical transmission system comprises an isolation module which is connected with an output port of a first coupler and is used for receiving an optical fiber loop input signal; the first end of the hollow-core optical fiber is connected with the isolation module, and the hollow-core optical fiber is used for transmitting an optical fiber ring input signal; the feedback module is connected with the second end of the hollow-core optical fiber and is used for returning the input signal of the optical fiber ring to the hollow-core optical fiber; and the isolation module is also connected with the acousto-optic modulator and is also used for outputting the returned input signal of the optical fiber ring to the acousto-optic modulator. The fiber loop input signal is transmitted back and forth in the single-section hollow-core fiber, so that the equivalent transmission distance of the single-section hollow-core fiber is doubled, noise cumulants such as amplified spontaneous emission noise and nonlinear distortion are remarkably reduced, the signal transmission quality and the system stability are improved, and the system performance is improved. And the control difficulty of the acousto-optic modulator and the operation and maintenance complexity of the system are reduced.

The present application relates to a kind of liquid leakage judgment and leakage location positioning system and method, including the broadband light source, spectrum analysis module and fiber coupler respectively connected on optical fiber circulator, fiber coupler is connected multiple groups of liquid leakage monitoring sensor respectively;Liquid leakage monitoring sensor includes at least two groups of fiber collimator arranged horizontally on the same axis, wherein a group of fiber collimator is connected fiber grating, and float is arranged in the direction perpendicular to the axis of two groups of fiber collimator;Broadband light source generates optical signal, and optical signal is sent to fiber collimator by fiber coupler, and the reflection signal generated by fiber grating is acquired by spectrum analysis module;The bottom of float has opening, and the liquid leakage enters the inside of float by opening and pushes it to rise, and the light path between two fiber collimators is shielded, and reflection signal disappears in spectrum analysis module, and the position of liquid leakage monitoring sensor corresponding to disappeared signal is positioned leakage position.

This invention discloses a lightweight, compact, three-axis integrated fiber optic inertial navigation device, belonging to the field of inertial navigation technology. Specifically, it relates to a lightweight, compact, three-axis integrated fiber optic inertial navigation device, comprising a housing, an inertial measurement unit (IMU), a magnetic shielding plate, and navigation control circuit components. The IMU includes three orthogonally arranged accelerometers, three orthogonally arranged fiber optic loop components, and an SLD (Single-Loop Light Source). The three fiber optic loop components share a single SLD light source, forming a three-axis integrated fiber optic gyroscope. The fiber optic loop components include a loop support, a 260m polarization-maintaining fiber optic loop, and a magnetic shield. The magnetic shield is fixed to the lower end face of the loop support, forming a closed magnetic shielding environment. The 260m polarization-maintaining fiber optic loop is located within this closed magnetic shielding environment. This invention optimizes the design of the IMU and navigation control circuit components of the fiber optic inertial navigation system, achieving magnetic shielding isolation of the fiber optic loop and physical isolation of heat-generating devices while reducing system weight and volume, thereby improving the stability of the navigation system.

The present application belongs to the field of distributed optical fiber sensing technology, and particularly relates to a kind of OFDR system phase noise compensation device and method based on or equivalent optical fiber loop auxiliary interferometer.The optical fiber 2x2 coupler and delay optical fiber of the present application constitute a loop and serve as the delay optical path of auxiliary interferometer, and the optical delay of laser will be doubled after each loop, thereby obtaining multiple beat signals with different optical delays.According to the different distances of the optical fiber to be measured on the main interferometer, the beat signal of the auxiliary interferometer with the closest optical delay is selected for compensation.The distance domain reflection signal of the whole sensing optical fiber can be obtained by splicing the compensated reflection signals at different distances, thereby realizing the phase noise compensation of the OFDR system in the whole range.The present application realizes the full-range and high-precision measurement of OFDR, and has the characteristics of simple structure, stable performance, low manufacturing cost and the like.