495 results about "Fiber ring" patented technology

The invention provides a distributed optical fiber temperature detection double-end correction device and method, and belongs to the technical field of optical fiber logging, the upper end of a logging optical cable is connected with a ground reference optical fiber ring, and the lower end of the logging optical cable is connected with an optical fiber grating sensor; the electronic temperature sensor is placed in the ground reference optical fiber ring, the measurement and control module is connected with the electronic temperature sensor, and the temperature of the ground reference optical fiber ring is measured through the electronic temperature sensor; the pump light source and the DTS measurement module are connected with the COM optical splitter; the optical switch is used for switching DTS distributed optical fiber measurement and optical fiber grating sensor measurement; temperature values measured by the DTS distributed optical fiber and the optical fiber grating sensor serve as reference data to adjust measurement parameters of the DTS measurement module, and double-end correction of DTS temperature measurement data is completed. The ground reference optical fiber is combined with the electronic thermometer, and the optical fiber grating sensor is adopted underground, so that distributed optical fiber temperature measurement double-end correction is realized.

The utility model discloses an integrated control high-voltage cascade energy storage device, which comprises an integrated main controller and three single-phase energy storage mechanisms, and the three single-phase energy storage mechanisms adopt a chain type three-phase star topology structure. Each single-phase energy storage mechanism is formed by cascading a plurality of PCS power modules, the direct current sides of the PCS power modules are connected with battery clusters in parallel, and each battery cluster is composed of a plurality of battery packs; the controlled end of each battery pack is connected with one single battery management unit, each energy storage chain link is controlled by one integrated cluster unit control module, and information interaction is carried out between each integrated cluster unit control module and the integrated main controller through an optical fiber ring network. According to the utility model, the information interaction between the battery cluster and the power unit and between the integrated cluster unit control module and the integrated main controller is realized, the control logic of the information interaction between the control part of the power conversion system PCS and the battery management system BMS is simplified, the response speed is improved, and the stable operation of the energy storage device is ensured.

The invention discloses an airborne combined measurement calculation method for closed-loop optical fibers, which comprises the following steps that: an orthogonally distributed three-axis closed-loop optical fiber gyroscope array acquires a Sagnac phase difference signal in real time, each optical fiber ring adopts an asymmetric pretightening force winding process, the pretightening forces of X / Y / Z axes are 12 + / -0.5 N, 8 + / -0.3 N and 15 + / -0.5 N respectively, the diameter ratio of the optical fiber rings is 1: 0.8: 1.2, environmental disturbance compensation is carried out, and the Sagnac phase difference signal is acquired in real time. Data of 48 PT1000 temperature sensors embedded in the axial direction of an optical fiber ring at the interval of 5 mm and full spectrum data of a three-axis vibration sensor at the frequency band of 0-2000 Hz are synchronously collected, and a coupling error model is constructed based on temperature gradient distribution and vibration spectrum characteristics. Therefore, through an asymmetric winding process, temperature-vibration coupling compensation, improved data fusion and dynamic closed-loop control, the problems of nonreciprocal errors caused by the symmetric winding process, insufficient environmental adaptability of single temperature compensation, limited nonlinear error processing capability of standard Kalman filtering and stability of a fixed parameter controller are solved; high-precision and high-reliability airborne combined measurement is realized.

The utility model discloses an OTDR (Optical Time Domain Reflectometer) optical module capable of eliminating a blind area at an initial section of an optical fiber. The OTDR optical module comprises an upper shell, a lower shell, a frame, a PCBA (Printed Circuit Board Assembly), the optical fiber and an electric connector, wherein the frame is installed between the upper shell and the lower shell, the middle of the frame is open to form a window, and a fiber coiling ring is formed on the top surface of the frame and surrounds the periphery of the window; the PCBA board is installed on the bottom face of the frame, and the electric device, the optical device and the lens unit which are installed on the PCBA board are located in the area of the window. After the optical fiber is butted with the lens unit, a section of optical fiber is wound on the fiber winding ring to form an internal fiber winding and then is led out of the upper shell; the internal coiled fiber is longer than the blind area of the optical fiber initial section; the electric connector is installed on the lower shell, serves as an electric interface and a data interface of the optical module and is electrically connected with the PCBA board. According to the utility model, the internal disc fiber is additionally arranged in the optical module, and the blind area of the initial section of the optical fiber is positioned in the internal disc fiber, so that the problem that a section of optical fiber behind the starting point of the optical fiber cannot be subjected to OTDR detection is solved.

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.

A spherical multi-axis optical fiber sensing device is formed by a three-axis optical interference sensor composed of a multi-level opto-mechanical integrated unit kit. The opto-mechanical integrated unit kit is composed of three fiber rings, which are respectively a large fiber ring, a medium fiber ring and a small fiber ring. The multi-level opto-mechanical integrated unit kit is combined with the use of the mechanism component technology that can be freely rotated and positioned to achieve the functional purpose of establishing a three-axis orthogonal optical fiber sensing unit in a single sphere volume.

The invention discloses a millimeter wave signal phase noise testing method based on ultra-stable laser, and the method comprises the steps: generating the ultra-stable laser through employing a common-cavity Brillouin laser frequency stabilization technology, taking the ultra-stable laser as a carrier wave, and carrying out the double-sideband modulation of a to-be-tested millimeter wave signal; frequency shifts of the two sidebands are different, the sideband with high frequency has more downward frequency shifts, the sideband with low frequency has less downward frequency shifts, the generated common-cavity Brillouin laser and the double-optical-sideband pumping laser are coupled and separated to obtain upper and lower double-sideband optical signals with different frequency intervals, and then beat frequency and mixing frequency are performed to generate an intermediate frequency signal with MHz magnitude; the noise characteristic of the intermediate frequency signal directly carries the phase noise of the to-be-tested signal, and the phase noise analyzer carries out noise spectrum density analysis and quantitative evaluation on the intermediate frequency signal to complete the phase noise test of the to-be-tested millimeter wave signal. The collaborative optimization problem that the reference source stability, the system noise and the to-be-tested signal noise are difficult to separate in the ultrahigh frequency signal noise test is solved.

The invention discloses a CAN network optical fiber communication method supporting ring network redundancy, a ring optical fiber communication network is constructed based on a plurality of CAN network optical fiber repeaters, the ring optical fiber communication network comprises two redundancy transmission lines, in a ring network mode, all CAN network optical fiber repeaters are divided into a control node and a plurality of common nodes, and the control node is connected with the common nodes. The control node works according to a set control node working rule, and the common node works according to a set common node working rule, so that when the current transmission line works normally, data transmission is carried out on the current transmission line in a one-way transmission mode, and when the current transmission line is abnormal, data transmission is carried out on the current transmission line in a one-way transmission mode. The CAN network communication reliability is improved by constructing the redundant optical fiber ring network, and meanwhile the problems that after a traditional CAN network-to-optical fiber repeater forms the redundant optical fiber ring network, CAN data can be circularly forwarded in the optical fiber ring network in an infinite mode, network storm is generated, and network paralysis is caused are solved.

The invention discloses a 24-channel optical fiber ring winding method which is characterized by comprising the following steps: S100, according to the length requirements of 24 groups of channel optical fibers, completing the fiber distribution work of 24 groups of optical fibers, and marking channel numbers; s200, feeding the optical fibers from the first channel to the twenty-fourth channel into optical fiber ring winding equipment, sequentially completing winding of the optical fibers from the first channel to the twenty-fourth channel according to a quadrupole symmetrical winding method, and measuring and ensuring length values; the working requirements are as follows: (1) after the optical fiber ring in each channel is wound in the winding process, two tail fibers are discharged along the fiber outlets in the side surfaces of the framework; and (2) three fiber outlets are uniformly distributed on the side surface of the skeleton in the circumferential direction, and tail fibers of eight channel optical fibers are discharged from each fiber outlet. According to the invention, a brand new 24-channel optical fiber ring winding method is designed, so that the problem of non-uniform discharge of channels of 24-channel optical fiber ring products is solved.

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.

The invention discloses a fiber ring repairing device. The fiber ring repairing device comprises a degradable elastic restraining bag and filler filled in the elastic restraining bag. Space in the elastic constraint bag comprises a positioning space, a supporting space and a limiting space, and the filler comprises first filler and second filler. The first filler is located in the positioning space, fixed in shape to form a positioning part, located on the outer side of the fiber ring crevasse and used for conveying and positioning. Corresponding parts of the supporting space and the limiting space in the elastic constraint bag can be folded under the non-filling condition and then enter the fiber ring crevasse, and then the second filling part flows into the supporting space and the limiting space and forms a supporting part and a limiting part after being solidified. And the part, corresponding to the supporting space, in the elastic constraint bag can be elastically deformed under the filling of the second filler so as to adapt to the shape of the crevasse of the fiber ring. The limiting part is located on the inner side of the fibrous ring crevasse, provided with a limiting face abutting against the inner side wall of the periphery of the fibrous ring crevasse and used for preventing the fibrous ring repairing device from being extruded out of the fibrous ring crevasse by the nucleus pulposus.

The invention discloses a mine disaster optical fiber intelligent monitoring, early warning and emergency rescue command decision-making system. The system comprises an industrial personal computer, an optical fiber ring network, a distributed optical fiber multi-gas monitoring subsystem, a distributed optical fiber temperature monitoring subsystem, a distributed optical fiber vibration monitoring subsystem and a distributed optical fiber mine pressure monitoring subsystem. The system has high sensitivity, multi-gas monitoring capability, high precision and comprehensive monitoring capability, and can monitor and early warn various parameter changes of a mine in real time, including gas concentration, temperature, vibration and pressure. The system has real-time monitoring and early warning capabilities, can accurately capture tiny changes and timely send out early warning signals, and helps mine monitoring personnel to take safety measures. The system has the functions of rescue command and emergency rescue, can quickly transmit environment information and disaster conditions to a rescue command center, and improves the rescue efficiency. The system also has strong data management and analysis capability, and helps mine monitoring personnel to better understand the environment change and trend of a mine and the change of disaster risks.

The invention discloses a single-photon non-vision-field target tracking system based on an unmanned aerial vehicle platform, which belongs to the field of non-vision-field imaging and is characterized in that a laser is connected with a scanning galvanometer assembly through a first nanosecond optical path switch and an optical fiber circulator to form an emission optical path for emitting laser pulses to relay reflecting surfaces corresponding to four predetermined positioning points; the scanning galvanometer assembly is connected with the photon detector through the collimating optical fiber, the optical fiber circulator and the second nanosecond optical path switch to form a receiving optical path capable of receiving echo photons; the main control module is electrically connected with the laser, the first nanosecond light path switch, the second nanosecond light path switch, the scanning galvanometer assembly, the photon detector, the time-to-digital converter and the high-frequency inertial measurement unit respectively, and can control each component to perform laser ranging, double-window gating, single-photon detection, inertial measurement unit sampling and timing according to a unified time sequence; and the three-dimensional coordinates of the current non-vision target are calculated by using the distance measurement data through an ellipsoid intersection solution method, so that non-vision target tracking is realized.

The invention discloses a periodic forked near-transformation limit nanosecond pulse mode-locked fiber laser and a generation method. The laser is characterized in that a fiber ring cavity comprises a wavelength division multiplexer, an erbium-doped fiber, a first polarization controller, a polarization analyzer, a dispersion control unit, an output coupler, a fiber isolator and a second polarization controller which are sequentially connected in a closed loop mode. The method comprises the steps that pumping continuous light is coupled into the laser through the wavelength division multiplexer; pumping continuous light is absorbed by using an erbium-doped fiber and is stimulated to radiate a gain pulse with a long wave band, and the generated pulse oscillates in a fiber laser cavity; under the combined action of a first polarization controller, an analyzer and a second polarization controller, an equivalent saturated absorption effect is generated by utilizing nonlinear polarization rotation generated when gain pulses are propagated in an optical fiber, and pulse mode locking is realized; the optical fiber laser works in an abnormal dispersion region, so that generated pulses meet the soliton area theorem, and near-transformation limit pulses are generated. According to the invention, nanosecond pulse period bifurcation output of the short-cavity fiber laser can be realized.

The invention discloses a high-precision liquid level measuring device and method based on sweep frequency interference measurement, belongs to the technical field of optical-mechanical-electrical integrated measurement, and is used for high-precision liquid level measurement. The light path is composed of a frequency sweep correction light path and a measurement calibration light path. The device comprises a sweep-frequency light source, an optical fiber splitter, a high-speed acquisition card, a computer, an optical fiber circulator, an optical fiber reflector, a Fabry-Perot (FP) etalon, a balanced photoelectric detector (BPD), a liquid level measuring probe and the like. The FP etalon realizes a sweep frequency correction function, a measurement calibration light path switches channels through the one-to-two photoelectric switch, and high-speed signal acquisition is carried out through the BPD and the high-speed acquisition card. The measuring process is free of mechanical movement and has the advantage of being free of maintenance; the FP etalon is introduced for nonlinear frequency sweeping calibration, the measurement precision is improved, the micron-level measurement precision can be achieved under the better experiment condition, and the non-contact measurement method can meet the requirement for high-precision liquid level measurement in the fields of chemistry, chemical engineering and the like.

The invention provides an optical path structure for improving the fineness of interference fringes of a Fabry-Perot sensor, which belongs to the technical field of optical fiber sensing and comprises a laser, a 2 * 1 optical fiber combiner, an optical fiber circulator, the Fabry-Perot sensor, a 1 * 2 optical fiber splitter, a photoelectric detector and an erbium-doped optical fiber amplifier. The laser generates a stable light source, and an optical signal enters the Fabry-Perot sensor through the 2 * 1 optical fiber combiner and the optical fiber circulator to generate interference fringes. Then, the 1 * 2 optical fiber beam splitter divides the optical signal into two parts, one part is transmitted to a photoelectric detector for signal detection, and the other part enters an erbium-doped optical fiber amplifier for amplification and is circulated back to the system through a feedback optical path. The optical path structure realizes multi-beam interference by introducing an optical path design of signal amplification and multiple feedback, the fineness of interference fringes is remarkably improved, and the sensitivity of the Fabry-Perot sensor in displacement and phase detection is further improved.

The invention particularly relates to a method for determining a magnetic shielding body material of an optical fiber ring, and solves the technical problems that the magnetic shielding effect is poor and the magnetic shielding performance requirement of an optical fiber gyroscope is difficult to meet due to the lack of an optimal selection method for a magnetic shielding body in the prior art. The invention discloses a method for determining a magnetic shielding body material of an optical fiber ring. The method comprises the following steps: 1) calculating relative permeability of each magnetic shielding material under different magnetic induction intensities; 2) establishing an optical fiber ring magnetic shielding simulation model; 3) simulating to obtain first magnetic induction intensity of a magnetic field environment where the optical fiber ring is located; 4) selecting the material of the magnetic shielding body on the outermost layer; and 5) performing simulation in sequence from outside to inside to obtain the magnetic induction intensity of the magnetic field environment where the optical fiber ring is located, and based on the magnetic induction intensity, selecting the magnetic shielding material with the highest relative magnetic conductivity in the multiple magnetic shielding materials in the step 1) in sequence as the material of the magnetic shielding body of the corresponding shielding layer until the material of each layer of magnetic shielding body in the optical fiber ring is determined.

The invention discloses an ultrasonic detection system and method based on all optical fibers, and relates to the technical field of photoacoustic detection. The system comprises a light-induced ultrasonic transmitting module, an optical ultrasonic sensing module and an all-optical ultrasonic probe (3), the photoinduced ultrasonic transmitting module comprises a pulse laser (1) and a first optical fiber (2); the optical ultrasonic sensing module comprises a second optical fiber (5), a third optical fiber (6), a fourth optical fiber (7), a circulator and isolator (8), a photoelectric detector (9), a tunable laser (10), an acquisition card (11) and a computer (12); and the all-optical ultrasonic probe (3) comprises an optical fiber ultrasonic transmitting group (3-1) and an optical ultrasonic sensing group (3-2). The probe design is improved, the manufacturing process and the system structure are optimized, the manufacturing repeatability and the performance consistency are improved, meanwhile, the contrast ratio and the resolution ratio of imaging are improved, and noise interference is reduced.

The invention discloses an optical fiber ring ultraviolet curing device and method. The optical fiber ring ultraviolet curing device comprises a box body, a feeding mechanism, a telescopic disc, a limiting driving mechanism, a fiber disc and an ultraviolet light source, the feeding mechanism is fixed on the box body, the telescopic disc is connected with the feeding mechanism, the limiting driving mechanism drives telescopic arms of the telescopic disc to stretch out and draw back, the fiber disc is located on the upper portion of the telescopic disc, and the ultraviolet light sources are fixed on the telescopic arms respectively. An optical fiber is wound on an optical fiber ring framework of a fiber disc, a tail fiber disc is in a ring shape, after the optical fiber ring framework is placed on the fiber disc, a limiting driving mechanism drives an ultraviolet light source to adjust the distance from the ultraviolet light source to the optical fiber ring framework, and a feeding mechanism drives a telescopic disc to enter a shielding cover; the optical fiber curing device is compact in structure, small in occupied space, good in curing effect, high in curing efficiency and safe and reliable to operate.

The utility model discloses an optical fiber ring packaging device, which comprises a packaging cover, an optical fiber ring and a packaging base, the packaging base is provided with an annular cavity, and the optical fiber ring is accommodated in the annular cavity. The packaging cover and the packaging base are connected in a matched mode to form a magnetic shielding face. The outer side joint and the inner side joint of the packaging cover and the packaging base are welded through laser. The laser direction is perpendicular to the magnetic shielding surface. According to the utility model, when the high-precision optical fiber ring is packaged and welded, the welding seam still has an anti-magnetic shielding function, and the magnetic field performance of the optical fiber ring is improved.

The present application relates to a fiber optic gyroscope with stress compensation. In addition to the existing fiber optic gyroscope comprising a light source, a coupler, a Y-waveguide, a fiber optic ring, a detector, and a signal processing circuit, a temperature sensor and a piezoelectric ceramic are added. The coupler is connected to the light source, the detector, and the Y-waveguide, respectively; and the signal control circuit is connected to the detector, the temperature sensor, the Y-waveguide, and the piezoelectric ceramic, respectively. Since the fiber optic ring is wound with a first optical fiber and a second optical fiber, the Y-waveguide and the fiber optic ring are connected via a first optical fiber pigtail and a second optical fiber pigtail, and the first optical fiber pigtail or the second optical fiber pigtail is also wound around the piezoelectric ceramic. During operation, the signal processing circuit controls the piezoelectric ceramic in real time to perform pressure compensation on the first optical fiber pigtail or the second optical fiber pigtail wound around the piezoelectric ceramic based on the sensitive angular velocity information and temperature information of the fiber optic gyroscope, thereby balancing the stress values ​​on both sides and thereby compensating for the zero drift of the fiber optic gyroscope caused by stress.

The invention discloses a power transmission line unmanned aerial vehicle communication networking system based on an optical fiber ring network, and relates to the field of power transmission line communication networks. The plurality of integrated base stations form an optical fiber ring network through the OPGW optical cable and the LTE MESH ad hoc network; the unmanned aerial vehicle executing the power transmission line inspection task and the corresponding fixed airport are accessed to an information intranet through an optical fiber ring network; wherein the integrated base station comprises an OPGW integrated base station and a MESH integrated base station; the OPGW integrated base station is deployed at a node with an optical fiber splice closure on a power transmission line tower, and is accessed to the information intranet in a wired connection mode; and the MESH integrated base station is deployed at a node, without an optical fiber splice tray, on a power transmission line tower, and is accessed to the OPGW integrated base station in a wireless connection mode. The power transmission line unmanned aerial vehicle communication networking system based on the optical fiber ring network can guarantee timely, safe and efficient large-scale data transmission.

A satellite system may have a constellation of communications satellites that provides services to users with electronic devices such as portable electronic devices and home / office equipment. The satellites may support communications between the electronic devices of the users and gateways. Each gateway may have satellite transceiver circuitry that transmits and receives satellite signals. Each gateway may also have an optical add-drop multiplexer coupled to a fiber ring and radio-frequency-over-fiber circuitry coupled between the satellite transceiver circuitry and the optical add-drop multiplexer. A metropolitan point-of-presence may be in communication with the fiber ring and may have modems for centrally processing communications (received and transmitted in an intermediate frequency) in the satellite system.

The invention relates to an optical fiber ring module with high magnetic shielding performance and a manufacturing method thereof, and solves the technical problem of limited magnetic shielding performance in the prior art. The shielding device comprises a base, a shielding framework sleeving the base and a shielding bottom cover, an optical fiber ring is arranged in the shielding framework; a Y waveguide, a coupler and a temperature sensor are mounted on the base; a first-layer upper shielding cover and a first-layer lower shielding cover are respectively arranged on the outer layer to realize first-layer full magnetic shielding; a second-layer upper shielding cover, a second-layer shielding cylinder and a second-layer lower shielding cover are correspondingly connected to realize second-layer full magnetic shielding; and a third-layer shielding cover is arranged, and the third-layer shielding cover and the third-layer shielding sleeve are correspondingly connected to realize third-layer full-magnetic shielding. Wherein the first magnetic shielding layer and the third magnetic shielding layer are made of magnetic conductive materials so as to shield interference of a low-frequency magnetic field, the middle second magnetic shielding layer is made of conductive materials so as to shield interference of a high-frequency magnetic field, and the magnetic shielding performance is improved through three-layer full magnetic shielding coating.

The invention discloses a narrow linewidth fiber laser based on random distribution feedback loop self-injection locking, and relates to the technical field of fiber lasers. The wavelength division multiplexer, the erbium-doped optical fiber, the optical band-pass filter, the optical coupler I, the optical coupler II, the polarization controller and the optical isolator are sequentially connected end to end to form an annular cavity, the pumping source is connected with the wavelength division multiplexer, and the random distribution feedback structure is connected with the optical coupler III to form an optical fiber ring to form a random distribution feedback ring. A first port and a third port of the optical circulator are connected with the first optical coupler and the second optical coupler respectively to form a self-injection structure, a second port of the optical circulator is connected with the third optical coupler, and the remaining output end of the second optical coupler serves as the output end of the annular cavity. The laser frequency drift of the annular cavity can be reduced by utilizing the random distribution feedback ring, the effective length of the random distribution feedback structure is increased by increasing the round-trip times of optical signals, a narrow-band gain peak can be ensured, stable narrow-linewidth single-frequency laser output can be obtained, and the linewidth narrowing efficiency and the environmental sensitivity are improved.

The invention discloses an optical fiber ring network optical cable link multi-mode physical information sensing method and system, and belongs to the technical field of optical fiber ring network communication link monitoring. In order to solve the technical problem that a fault of an electric power communication optical cable link is difficult to accurately identify and distinguish due to the coupling effect of multiple physical quantities such as external damage, stress and temperature, based on a single idle optical fiber, the phase change of a backscattering signal is obtained through a phase reduction technology; and a multi-mode physical quantity coupling model containing axial, radial and circumferential strain and temperature is constructed and inverted, so that quantitative distinguishing and positioning of stress, strain, temperature and vibration are realized. According to the method, a step-by-step decoupling strategy of first temperature compensation, then strain inversion and then vibration separation is adopted, and a two-stage discrimination mechanism of physical prior and machine learning is combined, so that the accuracy and interpretability of event recognition are remarkably improved. Depth perception and accurate fault positioning of the physical state of the optical cable link are realized.

The invention provides a high-sensitivity micro-gas-volume gas detection device and method based on a double-enhanced photo-thermal spectrum, and relates to the field of optical sensing, and the high-sensitivity micro-gas-volume gas detection device comprises a pump light source, a detection light source, a micro-nano optical fiber ring resonance module, a filter, a photoelectric detector, a signal processing unit and a control module. According to the high-sensitivity micro-gas-volume gas detection device and method based on the double-enhanced photo-thermal spectrum, double enhancement of photo-thermal and resonance detection is realized through the micro-nano optical fiber annular resonant cavity, so that nano-upgraded gas volume can be equivalent to an absorption optical path of dozens of meters, and the detection accuracy is improved. Therefore, high-sensitivity gas measurement under the condition of tiny gas flow is realized.

The invention relates to a nanosecond fiber laser and method for high-order chaotic pulses. A fiber ring cavity of the laser comprises a wavelength division multiplexer, an erbium-doped fiber, a first polarization controller, an analyzer, a second polarization controller, an output coupler, a dispersion control unit, a fiber isolator and a band-pass filter which are connected in sequence. The method comprises the steps that pumping continuous light is coupled into the laser through the wavelength division multiplexer; pumping continuous light is absorbed by using an erbium-doped optical fiber and is stimulated to radiate a long-wave-band gain pulse; under the combined action of the first polarization controller, the polarization analyzer and the second polarization controller, an equivalent saturable absorption effect is generated by utilizing nonlinear polarization rotation generated when gain pulses are propagated in an optical fiber, and large anomalous dispersion is introduced to realize generation of nanosecond pulses; through the band-pass filter, nanosecond pulses are allowed to be generated, and meanwhile, the nonlinear increasing speed of propagation and accumulation of the nanosecond pulses in the cavity is controlled, so that order-by-order generation of high-order chaotic pulses is realized. According to the invention, reliable output of high-order chaotic pulses can be realized.

The invention relates to the technical field of optical measurement, and provides an electro-optical modulator parameter measurement device based on an optical fiber ring resonant cavity, which comprises an optical signal modulation system, an optical fiber ring resonant cavity system and a signal acquisition system which are sequentially connected through optical fibers, the optical signal modulation system comprises a to-be-measured electro-optical modulator which modulates an optical signal and outputs a modulated signal; the optical fiber ring resonant cavity system comprises an optical fiber coupler and a linear piezoelectric ceramic optical fiber stretcher; an annular optical fiber is formed based on an optical fiber coupler, and a plurality of reciprocating optical signal loops are formed in the annular optical fiber. The linear piezoelectric ceramic optical fiber stretcher is used for changing the length of the annular optical fiber; the signal acquisition system acquires signals and calculates parameters. Compared with the prior art, the method has the advantage that the resolution during measurement is improved.

A single optical fiber ring-based current measurement unit for an electrolyzer zone, and an electrolyzer measurement system. The electrolyzer zone comprises a column busbar (7), two horizontal busbars (3-A, 3-B), two rows of anode conducting rods (2), and two rows of anodes (1), wherein the column busbar (7) is electrically connected to the two horizontal busbars (3-A, 3-B), the column busbar (7) transmitting a current to the two horizontal busbars (3-A, 3-B); each of the horizontal busbars (3-A, 3-B) is electrically connected to the anodes (1) by means of a corresponding row of anode conducting rods (2), the horizontal busbars (3-A, 3-B) being in contact with each anode conducting rod (2) and having an electrically conductive portion severing as the electrical connection portion of the two; and an optical fiber sensing ring of one optical fiber current sensor (5) encloses the electrical connection portion of at least one anode conducting rod (2) and the horizontal busbars (3-A, 3-B), a current value measured by the optical fiber current sensor (5) being the sum of anode currents of the anodes (1) corresponding to electrical connection portions within the optical fiber sensing ring. The use of a single optical fiber current sensor (5) enables accurate on-line measurement of the anode current in the electrolyzer zone, so that the measurement cost is significantly reduced; the accuracy and current efficiency are high; and energy saving, consumption reduction, and emission reduction are realized.