3738 results about "Core (optical fiber)" patented technology

The invention discloses a radioactive measurement data processing method for improving uranium exploration efficiency. The method comprises the following steps: standardized data acquisition: integrating a multi-parameter module, carrying out time-space synchronous acquisition of geological geophysical environment parameters, standardizing protocol alignment data, and supporting three-dimensional modeling; a three-dimensional coupling model is used for processing interference in a sub-module mode, LiDAR-DEM is used for correcting gamma attenuation in the terrain, an optical fiber thermopermeability instrument is used for correcting daughter errors in the hydrology, signal attenuation of a borehole is compensated through a drilling fluid chart, and a space-time continuous interference field is formed; performing dynamic equilibrium coefficient inversion: constructing equilibrium coefficient isoparametric mapping, and inputting rock core, logging and geochemical data into a random forest model; the transfer learning is trained by using historical data, and dynamic inversion and updating of a new area are carried out; intelligent data processing three-dimensional visualization: self-adaptive denoising and spectral shape matching reinforcement abnormity are carried out; constructing a three-dimensional model, and carrying out transfer learning to optimize the precision; the WebGL platform integrates multi-parameter display, virtual drilling functions and high-dimensional data intuitive interpretation.

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

The invention provides a real-time breast duct inner wall lesion recognition and positioning method and system based on optical fiber imaging, and relates to the technical field of medical image processing, and the method comprises the steps: obtaining a breast duct inner wall image sequence, extracting a displacement vector field, decomposing the displacement vector field into a dominant frequency and residual components, analyzing the dominant frequency phase to obtain a tissue motion period, an abnormal displacement area is screened from the residual error to establish a tissue anomaly map, an area descriptor is constructed through local wavelet coefficient analysis, a lesion core area is determined through density clustering, and finally the range and the expansion direction of a lesion area are determined through a multi-scale radial basis function and isoline analysis. According to the invention, real-time accurate identification and positioning of the lesion of the inner wall of the breast duct can be realized.

The invention relates to the technical field of hydropower engineering, and discloses a single-core self-healing type looped network networking method and system, and the method comprises the steps: dividing a whole network into a plurality of sub looped networks; each sub-ring network operates independently; the light switch in each sub-ring network adopts an A / B end connection mode; reversely connecting the B end of the last measuring point to the A end of the initial measuring station by using an optical fiber to form a closed physical structure; configuring a protocol on the switch, and controlling a data flow path through the protocol; different sub-ring networks are connected through RJ45 ports, and a CAT5E shielded twisted pair or an Ethernet interface is used; when a certain node or link fails, the protocol automatically triggers a switching mechanism; the master station optical transceiver monitors the states of all nodes in real time and displays fault points through a network management interface. The system comprises a sub-ring network module, a control data flow module and a fault point display module. The problems that a traditional networking method of hydropower engineering is poor in reliability, and self-healing cannot be achieved after an intermediate node is disconnected are successfully solved.

A medical device system includes a stylet with an optical fiber and a console operatively coupled to the stylet. The optical fiber can include an electrically conductive concentric tube configured to transmit electrical signals and a plurality of core fibers within the concentric tube. Each of the plurality of core fibers can include a plurality of sensors, and each the plurality of sensors can be configured to reflect a light signal of a different spectral width based on received incident light and change a characteristic of the reflected light signal based on a condition experienced by the stylet. The console includes one or more processors and a non-transitory computer-readable medium with logic that causes operations including providing an incident light signal to the optical fiber and receiving reflected light signals of different spectral widths of the received incident light by the plurality of sensors.

The invention provides a hollow-core optical fiber cable fiber breakage detection method based on a reference optical fiber and an optical cable, and belongs to the technical field of optical fiber communication. The method comprises the following steps: acquiring monitoring data of a reference optical fiber in a hollow-core optical fiber cable, and performing quality evaluation on the data to generate a signal quality comprehensive score; when the score is higher than a preset threshold value, feature extraction and dynamic weighted fusion are carried out to generate a comprehensive feature vector; outputting a fiber breakage probability by using the fiber breakage state recognition model, calculating a fiber breakage risk value through a prediction model in combination with time sequence data, and obtaining a fiber breakage risk index through a risk fusion algorithm; and finally, matching and executing a hierarchical response strategy according to the risk index. According to the invention, multi-modal data fusion, intelligent state identification and active early warning are realized, and the reliability, precision and operation and maintenance efficiency of broken fiber detection are significantly improved.

The invention discloses a multi-mode optical signal transmission method and device, electronic equipment and a storage medium, and relates to the technical field of computers.The transmitted data stream is divided into a control signal and a data signal, the control signal is a visible light wave band, the data signal is an infrared wave band, and the control signal and the data signal are combined to a single multi-core optical fiber through a combiner; the optical network controller allocates subcarrier resources as required according to the change of network flow in a spectrum dynamic allocation mode to perform data transmission, so that the subcarrier resource allocation adapted to the change of network flow improves the dynamic adaptability, and the allocation of the subcarrier resources as required improves the equipment cooperation efficiency, and in the data transmission process, the data transmission efficiency is improved. Clock synchronization and signal encryption are realized through a quantum key distribution mode, and the security is improved.

The invention provides a high and low temperature alternating environment temperature and pressure mixed signal decoupling method and system based on a multi-core optical fiber. According to the method, temperature and pressure mixed signals are synchronously acquired through phase difference data of a plurality of fiber cores, and multi-channel mixed sensing signals are generated; performing mechanical stress suppression on the multi-core optical fiber by using a thermal expansion adaptive packaging structure to form an anti-deformation optical fiber assembly; carrying out adaptive time slot distribution on the mixed sensing signal based on a time division multiplexing time sequence to generate a synchronous calibration signal; spectral features of the synchronous calibration signals are separated through the spectral analysis technology, scanning parameters are dynamically adjusted in combination with the temperature change rate and the deformation quantity, and temperature and pressure feature data are extracted; and performing decoupling operation on the feature data through the coupling model, and dynamically correcting the model parameter weight based on the deformation quantity feedback data to obtain a temperature parameter and a pressure parameter. According to the invention, the accuracy of synchronous decoupling measurement of temperature and pressure in a high-low temperature alternating environment is realized.

An article of manufacture including a fiber optic termination of a small core optical fiber for use with a surgical laser apparatus (the output from which may be characterized by a high M2 factor) or other high-power or high-energy laser (including an appropriate fiber laser) is configured for safe and efficient coupling of light at a large laser focal point and / or to enable the process of coupling of radiant intensities exceeding the silica fiber damage thresholds and / or those ionizing the air if fully focused therein. The termination may include a glass cylinder structured to include a core region and a glass cladding region the ratio of dimensions of which is substantially equal to the ratio of respectively-corresponding dimensions of the employed optical fiber. A method of propagating light through such article of manufacture.

The invention is suitable for the technical field of toll station management, and provides an expressway toll station remote seat guarding and special situation vehicle handling system, which comprises a front-end sensing layer, a rear-end sensing layer and a control layer, the lane equipment comprises a photoelectric sensor, an infrared height limit alarm, a license plate recognition camera, an ETC antenna, an acousto-optic warning ball and a self-service equipment sensor; the network transmission layer is connected with lane equipment, a sentry box cabinet, a machine room core switch and a monitoring center through an optical fiber network; the remote control layer is composed of a remote seat center, and the remote seat center can carry out video monitoring, visual intercom and remote control; and the abnormity alarm layer is used for carrying out early warning on vehicle detention, vehicle height exceeding, ETC passing faults, toll evasion vehicles and handrail abnormity. The vehicle state can be sensed in real time, data are gathered to a remote seat center through a network transmission layer, an information island is broken, and special conditions can be automatically processed.

The invention provides a low-loss hollow-core optical fiber and a preparation method thereof. The hollow-core optical fiber comprises an outer cladding, and a plurality of anti-resonance units and a plurality of cladding supplementing units which are connected to the inner wall of the outer cladding, the anti-resonance units are evenly distributed along the inner wall of the outer cladding at equal intervals, the cladding supplement units are arranged between the adjacent anti-resonance units, and the anti-resonance units surround to form a fiber core area in the outer cladding. The anti-resonance unit comprises an outer anti-resonance tube, a first inner anti-resonance tube, a second inner anti-resonance tube and a substrate; the opening of the substrate faces the center of the outer cladding layer and is tightly attached to the inner wall of the outer cladding layer; the cross sections of the outer anti-resonance tube and the first inner anti-resonance tube are arc-shaped, the openings face the substrate, and the two ends are connected to the two ends of the substrate; the second internal anti-resonance tube is connected to the inner wall of the substrate; the cladding supplementing unit is of a circular or arc-shaped structure. In the drawing process of the optical fiber, the anti-resonance unit of the hollow-core optical fiber has good structural stability.

The invention relates to the technical field of coal mine telecommunication, and discloses a coal mine underground integrated private network coverage system based on a 5G communication and AR double-transmitting selective-receiving technology, an efficient transmission and baseband processing network is constructed by taking a macro base station as a core on the ground and matching with PTN equipment and a BBU, a 5G micro base station and an RRU are deployed under the ground for a complex environment, and low-loss signal coverage is realized through optical fibers. The AR double-transmitting selective-receiving module ensures that underground data are not lost and have no error through redundant coding and double-link transmission; the edge computing module sinks data processing to the underground, reduces transmission delay and optimizes resource allocation; and the system monitoring and interference suppression unit monitors the operation state in real time, performs multi-stage alarm and resists multipath effect and electromagnetic interference, and finally realizes integration of communication above and under the well, reliability of data transmission, high efficiency of resource utilization and stability of system operation, thereby providing solid communication support for safety production, equipment management and control and personnel scheduling under the coal mine.

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 control method and system of a high-power optical fiber amplifier, and relates to the technical field of optical fiber amplifiers, and the high-power optical fiber amplifier comprises a first-stage gain unit and a second-stage gain unit which are sequentially arranged along the transmission direction of light; the control method of the high-power optical fiber amplifier comprises the following steps: starting the high-power optical fiber amplifier according to a starting sequence of firstly starting a first-stage gain unit and then starting a second-stage gain unit; and closing the high-power optical fiber amplifier according to a closing sequence of firstly closing the second-stage gain unit and then closing the first-stage gain unit. According to the control method and system, the optical fiber amplifier can be controlled to realize relatively high power output, so that the optical fiber amplifier is suitable for being applied to a hollow-core optical fiber transmission system, the high-power optical fiber amplifier can be prevented from generating a huge reverse ASE signal to burn an optical path device under the condition of no input optical signal, and the application safety and reliability of the optical fiber amplifier are improved.

The invention discloses a hollow-core anti-resonance optical fiber with a connecting piece structure, which comprises an outer cladding and an inner cladding, and is characterized in that the inner cladding comprises a plurality of anti-resonance units, the anti-resonance units are arranged at intervals along the circumferential direction of the inner wall of the outer cladding, and a circular fiber core area is enclosed by the anti-resonance units; each anti-resonance unit comprises two or more layers of anti-resonance tubes with different radiuses, and at least one anti-resonance unit is connected with a connecting sheet; the connecting sheets are connected with the inner and outer adjacent anti-resonance tubes in the same anti-resonance unit, or the connecting sheets are connected with the anti-resonance unit and the inner wall of the outer cladding layer; the anti-resonance tube located on the outermost layer in the anti-resonance units is an outer anti-resonance tube, and the ratio of the cross section area of the connecting piece to the cross section area of the single outer anti-resonance tube is 0.5-10%. According to the invention, through the arrangement of the connecting sheets, adhesion between different anti-resonance tubes and between the anti-resonance tubes and the inner cladding layer is not easy to occur in the drawing process, unification of an actual structure and a design structure is realized, resonance loss is reduced, and introduction of extra resonance loss is avoided by limiting the sectional area of the connecting sheets.

The invention discloses a multi-core optical fiber multichannel demodulation system for three-dimensional displacement measurement of a mechanical oscillator, which comprises a light source module, a multi-core optical fiber sensing probe, a photoelectric detection module and a signal processing module. A mapping model between multi-channel optical signals and displacement is established, decoupling and high-precision measurement of three-dimensional displacement are realized through a matrix demodulation algorithm, the system takes a multi-core optical fiber as an integrated probe structure, free space optical path alignment is not needed, an optical path is stable, and packaging is simple and convenient; compared with a traditional single-core optical fiber displacement sensing scheme, displacement components of the mechanical oscillator in the three orthogonal directions can be obtained at the same time, and the method has the advantages of being high in measurement precision, high in anti-interference capacity, good in real-time performance, compact in system structure and the like and can be widely applied to the fields of mechanical oscillator displacement measurement, structure health monitoring, precision manufacturing, micro-nano operation positioning and the like.

The invention discloses a high-temperature-resistant flame-retardant carbon fiber cable and an intelligent preparation method thereof, and relates to the technical field of power cables, and the cable is composed of a composite bearing core, a first / second electrical isolation belt, a stranded conductor, an annular composite bearing layer, a high-temperature-resistant main insulator and a low-smoke halogen-free outer sheath. The force bearing core is formed by bundling carbon fiber micro rods, elastic reset layers are arranged between the micro rods, micro-particle friction layers are formed on the outer surfaces of the micro rods, and a stable friction-rebound interface is constructed. A fire-resistant barrier, a phase change microcapsule filling layer and a fiber bragg grating can be arranged, and fire resistance, thermal peak suppression and on-line monitoring are considered. And closed-loop control of pultrusion, surface activation, coating and on-line thickness measurement / friction test is carried out in the manufacturing process. The cable can be operated at 200 DEG C for a long time and at 250 DEG C for a short time, the residual elongation is less than or equal to 0.10%, and light weight, high strength, high temperature resistance, low smoke and flame retardance are realized.

The invention discloses a parallel imaging OCT (Optical Coherence Tomography) system based on a metasurface area array, which relates to the technical field of medical instruments, is small in size and can realize intraocular single-shot area array imaging and a three-dimensional position depth perception function by using metasurface and optical coherence tomography imaging information in a sample tissue with a limited size. According to the technical scheme, a light beam emitted by a laser is divided into two paths through a beam splitter, and the two paths enter a sample arm module and a reference arm module respectively; the sample arm module is a probe and comprises a multi-core optical fiber and a first metasurface; the reference arm module comprises a collimator, a motor and a right-angle reflector; the probe enters a sample tissue, a light beam is focused on the sample tissue and then is backscattered, the backscattered light beam reversely passes through the first metasurface, the multi-core optical fiber, the beam splitter, the second metasurface, the third lens, the grating and the focusing lens and then forms a spectral line beam on the CCD sensor, and the computer reads a signal from the CCD sensor and performs three-dimensional reconstruction imaging on the sample tissue.

The invention discloses a rotary shrinkage type secondary coupling device and a laser fiber conduit thereof, the rotary shrinkage type secondary coupling device comprises a mounting seat, a first mounting cylinder and a second mounting cylinder, the first mounting cylinder and the second mounting cylinder are fixedly connected to two sides of the mounting seat, and a rotary sleeve assembly is rotatably mounted in the first mounting cylinder to clamp a large-core-diameter fiber group. A sliding sleeve assembly is slidably sleeved with the second installation cylinder, a small-core-diameter optical fiber set is clamped, and the laser overlapping area of a laser optical fiber guide pipe in the rotary sleeve assembly and a laser optical fiber guide pipe in the sliding sleeve assembly is controlled by rotating the rotary sleeve assembly. And the telescopic distance adjusting assembly is used for controlling and adjusting the distance between the laser optical fiber guide pipe in the rotary sleeve assembly and the laser optical fiber guide pipe in the sliding sleeve assembly, so that controllable coupling of the large-core-diameter optical fiber group and the small-core-diameter optical fiber group is realized, and coupling of various types of small-core-diameter optical fiber groups can be conveniently and quickly adapted. And moreover, while the passing ability and the treatment effect of the catheter are ensured, the large-core-diameter optical fiber group can be repeatedly used only by abandoning the small-core-diameter optical fiber group part, so that the cost of an anti-ultraviolet optical fiber material is greatly saved.

A system and method directed to detecting placement of a medical device within a patient body, the system including a medical device including a multi-core optical fiber having a plurality of core fibers. Each of the plurality of core fibers can include a plurality of sensors each configured to reflect a light signal having an altered characteristic due to strain experienced by the multi-core optical fiber. The system can further include logic configured to determine a 3D shape of the medical device in accordance with the strain of the optical fiber. The logic can be configured to define a reference plane for the 3D shape and render an image of the 3D shape on a display of the system in accordance with the reference plane.

The invention relates to the technical field of engineering plastic detection, and particularly discloses an aging detection and evaluation method and system suitable for nylon 6 in a marine environment, the system comprises nylon 6 as a core layer, an aging response color-changing material as a surface layer and a middle layer located between the core layer and the surface layer; the thickness of the middle layer is 200-250 [mu] m, and the composite conductive film is transferred to the position 0.2 mm below the surface of the nylon 6 component in a hot pressing mode; the thickness of the surface layer is 0-200 microns and is realized by spraying an aging response color-changing material solution. By integrating the specially designed aging response color-changing material and the conductive film into the nylon 6 matrix, real-time, visual and efficient detection of the aging process is realized. According to the method, the problem that equipment such as a traditional optical fiber spectrometer is complex and expensive is solved, the convenience of field detection is greatly improved through double signal output of color gradient indication and simple electronic reading, and a brand new technical solution is provided for life prediction and preventive maintenance of nylon 6 components in ocean engineering.

The invention relates to the technical field of power transmission and cable monitoring cables, in particular to an anti-interference optical fiber monitoring cross-linked cable and a forming and manufacturing method, and the cable sequentially comprises a cable core layer, a monitoring function layer, an electromagnetic shielding layer, an insulation protection layer and an outer protection layer from inside to outside; the monitoring function layer is tightly wound on the outer surface of the cable core layer in a spiral shape, the electromagnetic shielding layer is located between the monitoring function layer and the insulation protection layer, the electromagnetic shielding layer is of a multi-layer structure, the inner layer of the electromagnetic shielding layer is a permalloy belt, and the outer layer of the electromagnetic shielding layer is a tinned copper woven mesh. And a plurality of rat-proof and ant-proof composite layers are arranged on the outer side wall of the outer protective layer at intervals along the length direction of the outer protective layer. The monitoring function layer is spirally and tightly wound on the outer surface of the cable core layer, the design enables the optical fiber and the cable core layer to be tightly attached, it is ensured that the temperature change and mechanical deformation of the cable core layer can be rapidly transmitted to the optical fiber, and the problem of monitoring lag caused by gaps in a traditional loose tube structure is solved.

The invention relates to the technical field of special optical fibers, in particular to a polarization-maintaining hollow-core anti-resonance optical fiber which comprises an outer cladding, an inner cladding, a fiber core, a first-class anti-resonance unit and a second-class anti-resonance unit. The inner cladding is arranged in the outer cladding, and the fiber core, the first-class anti-resonance unit and the second-class anti-resonance unit are arranged in the inner cladding; the first-class anti-resonance unit does not comprise a coupling thin wall, the second-class anti-resonance unit is provided with a coupling thin wall close to the fiber core side, and the coupling thin walls are two thin walls which are extremely close to each other and are not in contact with each other. According to the invention, high birefringence and broadband low transmission loss can be realized at the same time.

The invention relates to the technical field of passive optical networks, and discloses a dual-core optical fiber link loss self-repairing and redundancy switching method, which comprises the following steps of: establishing a resonance transmission state sensitive to physical disturbance; when the state is damaged due to disturbance, forced reconstruction and secondary confirmation are executed firstly instead of being switched immediately so as to distinguish transient impact and a hard fault, and the state is physically switched to a standby link only after the hard fault is confirmed. A traditional indirect mode depending on external measurement and threshold judgment is changed, and judgment delay and response delay are avoided; a secondary confirmation mechanism effectively avoids unnecessary switching caused by transient disturbance, and the operation stability of the system in a complex environment is improved.

The invention provides a short-wave multi-mode hollow-core anti-resonance optical fiber and a preparation method thereof, and relates to the technical field of optical fibers, and the short-wave multi-mode hollow-core anti-resonance optical fiber comprises an outer sleeve and a plurality of anti-resonance units which are arranged along the circumferential direction of the inner wall of the outer sleeve in an array manner; a central cavity enclosed by the plurality of anti-resonance units forms a fiber core area; the anti-resonance unit comprises at least three layers of anti-resonance tubes with different radiuses and two supporting rods arranged between two adjacent layers of anti-resonance tubes; wherein the two supporting rods in each layer are oppositely and obliquely arranged in pairs by taking the radial direction of the optical fiber as a symmetry axis, and the supporting rods on the same side are sequentially arranged along the same radius of the anti-resonance unit. Therefore, the waveguide filter has the advantages of being suitable for the 850 nm wave band, and being capable of supporting more high-order guided modes while giving consideration to low loss.

The invention relates to an ultralow-loss hollow-core anti-resonance optical fiber with a birefringence structure, which comprises an outer cladding and an inner cladding, the inner cladding is composed of anti-resonance structure units, the anti-resonance structure units are arranged along the circumferential direction of the inner wall of the outer cladding and are connected with the inner wall of the outer cladding, the inner cladding comprises four anti-resonance structure units, and the anti-resonance structure units are arranged along the circumferential direction of the inner wall of the outer cladding and are connected with the inner wall of the outer cladding. The four anti-resonance structure units are evenly distributed at intervals in the circumferential direction and comprise two long-axis anti-resonance structure units and two short-axis anti-resonance structure units, the two long-axis anti-resonance structure units are symmetrically arranged on the two sides of the inner wall of the outer cladding layer, and the two short-axis anti-resonance structure units are symmetrically arranged on the other two sides of the inner wall of the outer cladding layer. A central cavity wrapped by an inner wrapping layer formed by the four anti-resonance structure units forms an elliptical fiber core with a long axis and a short axis. According to the invention, the transmission loss can be reduced while the high birefringence performance is maintained, the shape of each part of the microstructure cladding is regular, and the preparation is convenient.

The invention discloses a dynamic submarine cable three-dimensional reconstruction method and device, electronic equipment and a storage medium, which are used for solving the technical problem of failure of three-dimensional reconstruction of a dynamic cable caused by low shape sensing accuracy and stability of the dynamic submarine cable in the prior art. The method comprises the following steps: firstly, calculating a strain value of each fiber core in the multi-core optical fiber based on spectral drift, and performing characteristic curvature vector inverse solution by combining the strain value of each fiber core to obtain a discrete bending direction set and a discrete curvature set; respectively carrying out discrete fitting on the discrete bending direction set and the discrete curvature set until the bending direction and the optical fiber curvature at each position in the multi-core optical fiber are fitted; the optical fiber torsion is solved according to the bending direction, a space curve is solved based on the optical fiber curvature and the optical fiber torsion, and the space curve corresponds to the axis track of the multi-core optical fiber; and finally, performing three-dimensional reconstruction on the submarine cable according to the axis track to obtain the three-dimensional shape of the submarine cable.

A distributed composite geotechnical sensor disclosed by the present invention comprises a multi-core cable, an optical fiber sensing member, at least two composite sensing members and a plurality of connectors, the multi-core cable is used for transmitting charge signals, and the optical fiber sensing member and the multi-core cable are arranged in parallel and at an interval and are used for monitoring temperature and stress. The at least two composite sensing pieces are sequentially arranged at intervals along the length direction of the optical fiber sensing piece, are arranged in the same core with the optical fiber sensing piece and are used for monitoring dynamic stress waves or vibration, and the plurality of connecting bodies are respectively arranged at two ends of the composite sensing pieces and are connected with the multi-core cable, the optical fiber sensing piece and the composite sensing pieces. The electric connector is used for electrically connecting the multi-core cable with the composite sensing piece. According to the invention, the problems of relatively single monitoring index and incapability of positioning due to the fact that a traditional piezoelectric geotechnical cable can only monitor external disturbance information and cannot realize distributed monitoring can be effectively solved.

A system, apparatus and method directed to detecting malposition of a medical device within a vessel of a patient, such as an Azygos vein. The medical device can include a multi-core optical fiber including a plurality of core fibers, where each of the plurality of core fibers includes a plurality of sensors is configured to reflect a light signal based on received incident light, and change a characteristic of the reflected light signal for use in determining a physical state of the multi-core optical fiber. The system can include a console having non-transitory computer-readable medium storing logic that, when executed, causes operations of providing a broadband incident light signal to the multi-core optical fiber, receiving reflected light signals, processing the reflected light signals, and determining whether the medical device has entered the Azygos vein of the patient based on the reflected light signals.

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