151 results about "Fiber ring" patented technology

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 application discloses a communication method, device, system and train, relates to the field of optical fiber communication, and is applied to a processor in any compartment of a train, wherein the processor is connected with an optical fiber ring network, the processor and train communication equipment in the compartment perform communication data interaction, and then the processor and the optical fiber ring network perform communication data interaction in the form of optical signals, so that the train communication equipment in different compartments can communicate with each other. The communication data is not easy to be lost and is not easy to be affected by electromagnetic interference through the mode of data transmission by optical fibers instead of cables, so that the communication quality of the train communication equipment is improved. Moreover, the communication data of multiple train communication equipments is converted into optical signals and transmitted in the form of a bundle of light, so that multiple communication networks are not needed, and only one optical fiber ring network can realize data transmission of multiple train communication equipments at the same time, so that the complexity of the wiring environment in the train is reduced, and the total weight of the train is reduced.

This invention discloses a magnetically controlled end-face protection device for hollow optical fibers and its preparation method. The device includes: a fixed base for fitting and fixing to the periphery of the hollow optical fiber end; a magnetically controlled hollow fiber ring composed of a polymer matrix and pre-magnetized magnetic particles dispersed in the polymer matrix, capable of radial contraction or radial expansion deformation under the action of an external magnetic field; the magnetically controlled hollow fiber ring is disposed on the fixed base and fitted to the hollow optical fiber end, forming a physical barrier to the end face of the hollow optical fiber in the radial contraction state; and a flexible protective layer disposed on the inner wall surface of the magnetically controlled hollow fiber ring. The end-face protection device of this invention can achieve remote reversible protection of the hollow optical fiber end face and zero-power standby.

The application discloses a kind of time division multiplexing three-axis wide spectrum light source resonant type fiber-optic gyroscope detection systems and methods, belong to gyroscope optical system design field.System is constituted by optical system and signal detection system, and optical system includes a wide spectrum light source, a push-pull Y waveguide, a circulator, three mutually orthogonal transmission type fiber ring resonant cavity, two sections of delay optical fiber and a photoelectric detector;Signal detection system includes modulation and demodulation module, time division decoupling module and low-pass filter module.Three transmission type fiber ring resonant cavities are sequentially connected, and the time of optical signal reaching three fiber ring resonant cavities is different by being set delay optical fiber between adjacent two transmission type fiber ring resonant cavities.The application ingeniously designs three fiber ring resonant cavities to form three-axis integrated structure.In this way, the time difference of three-axis signals is utilized, and multiplexing in time domain can be realized without adding additional devices.

The invention belongs to the technical field of fiber-optic gyroscopes, and particularly relates to an acceleration-based fiber-optic gyroscope vibration error compensation method and an inertial measurement unit. Based on normal strain, optical fiber dielectric impermeability tensor variable quantity, refractive index variable quantity of light in the fast axis direction and phase variable quantity corresponding to a sensitive axis of an optical fiber gyroscope, quantitative relations between the phase variable quantity and the fast axis direction of the optical fiber and between the phase variable quantity and the length of a micro-section optical fiber are established, and the equivalent value of the stress borne by the optical fiber and the phase difference of an optical fiber ring is obtained; the linear relation between the phase difference equivalent value and the angular velocity to be compensated of the fiber-optic gyroscope is determined, the relation of converting the vibration acceleration to the phase to be compensated is established, and the required compensation coefficient is calibrated by combining a sinusoidal vibration test to compensate the vibration error of the fiber-optic gyroscope. According to the invention, vibration error compensation of the fiber-optic gyroscope can be realized without adding extra devices, and the real-time performance and accuracy of error compensation are improved.

The application provides a high-precision optical fiber winding system and method, which comprises a winding driving device arranged on one side of a glue tank, the winding driving device is used for driving the rotation of an optical fiber ring, and the optical fiber ring is at least partially immersed in the glue in the glue tank; a transverse moving mechanism is further arranged, the transverse moving mechanism is provided with an optical fiber guide wheel, the optical fiber guide wheel is used for guiding the reciprocating movement of the optical fiber, the moving direction of the optical fiber guide wheel is parallel to the axis of the optical fiber ring; a camera is further arranged, the camera is used for collecting the images of the optical fiber and the optical fiber ring; and a focusing curing laser device is further arranged, the focusing curing laser device is used for curing the glue between the optical fiber and the optical fiber ring. The scheme of winding the ring in the glue can overcome the straightness problem of the optical fiber by using the viscosity of the glue, and overcome the electrostatic repulsion problem between the optical fibers by using the glue. In cooperation with the focusing curing laser device, a low-power light beam can be converged into a focal point light source to perform point curing on the optical fiber through the glue.

The application relates to the technical field of fiber-optic gyroscopes, in particular to a preparation method of a two-in and two-out mirror image fiber-optic ring, which comprises the following steps: measuring two optical fibers with required lengths; marking the endpoints and the midpoints of the two optical fibers respectively; calculating a winding sequence change point and marking the same on the two optical fibers respectively; winding the two optical fibers on a fiber-optic ring skeleton in a mirror image symmetrical manner alternately by adopting a quadrupole symmetrical winding method until the winding sequence change point; changing the winding sequence of the two optical fibers; repeating steps d and e until the endpoint marks at the two ends of the optical fibers; and leading out four optical fiber tail fibers from the fiber-optic ring skeleton and fixing the same. According to the preparation method of the two-in and two-out mirror image fiber-optic ring, the two optical fiber rings have a mirror image relationship in space, so that the temperature phase errors generated by the two wound optical fiber rings are consistent, the phase errors caused by temperature changes in the Shupe effect can be compensated after joint signal processing, and the precision of the fiber-optic gyroscope is further improved.

The application provides a multi-stage coaxial mechanism for optical fiber winding, a base frame, and a triple shaft structure on the base frame. The triple shaft structure comprises a triple shaft rotating base connected with the base frame, a driven concentric outer shaft, a driving shaft and a driven concentric inner shaft which are sequentially sleeved on the inner side of the triple shaft rotating base and can synchronously rotate. A driven unlocking mechanism is arranged on one side of the triple shaft structure and is used for switching the synchronous or independent rotating state of the driven concentric outer shaft, the driving shaft and the driven concentric inner shaft, thereby solving the problem of rotating mode switching of the optical fiber ring tool skeleton, the fiber separating disc and the optical fiber guide assembly.

The utility model relates to the field of optical fiber interference sensors, and discloses an M-Z interference sensor with a small excitation group velocity dispersion difference mode structure. Comprising a light injection single-mode optical fiber, a small-core-diameter step multimode optical fiber, a wide annular core optical fiber, an annular core optical fiber, a gradient refractive index multimode optical fiber, a large-core-diameter step multimode optical fiber and a light receiving single-mode optical fiber which are connected in sequence. The wide annular core optical fiber comprises a third quartz cladding and a third quartz fiber core, and the third quartz fiber core annularly wraps a third quartz layer; the annular core optical fiber comprises a fourth quartz inner wrapping layer, a fourth quartz fiber core and a fourth quartz outer wrapping layer, the fourth quartz inner wrapping layer is annularly wrapped by the fourth quartz fiber core, the fourth quartz fiber core is annularly wrapped by the fourth quartz outer wrapping layer, and the optical fiber radial refractive index distribution index of the gradient refractive index multimode optical fiber is 1.95-2. According to the scheme, the annular core optical fiber is used for injecting light to the gradient refractive index multimode optical fiber, two modes with smaller group velocity dispersion difference can be excited to interfere, and the sensitivity of the sensor is improved.

This invention relates to fiber optic ring assemblies, specifically to a fiber optic ring assembly and a sealing process method to improve its long-term stability. This addresses the technical problems of existing fiber optic ring assemblies, such as the inability to guarantee the accuracy performance of the fiber optic ring when exposed to air, poor sealing performance at the small holes in the fiber optic ring shell, and slippage of the fiber optic ring and pigtails from the fiber optic ring shell due to weak adhesive. The invention includes a fiber optic ring shell and a fiber optic ring. The fiber optic ring shell includes a fiber optic ring frame and a cover plate, which are sealed together. The fiber optic ring is installed within the cavity formed by the fiber optic ring frame and the cover plate. The invention also includes a flexible absorbent material covering the fiber optic ring. The flexible absorbent material fills the space within the cavity of the fiber optic ring shell, excluding the space occupied by the fiber optic ring. A channel is provided on the fiber optic ring shell connecting the cavity to the outside. At least one pigtail of the fiber optic ring extends from this channel. The channel is sealed.

This invention relates to a lightweight, miniaturized 3S configuration triaxial integrated fiber-MEMS inertial measurement unit, belonging to the field of measurement devices. It includes a base cover, a power supply and detection board assembly located on the top of the base cover, a light source assembly located above the power supply and detection board assembly, a MEMS assembly mounted above the light source assembly, a base fixed to the base cover, fiber optic ring assemblies fixed to the base, and a reference mirror fixed to the top of the base. The power supply and detection board assembly, the light source assembly, and the MEMS assembly are all arranged inside the base. The three fiber optic ring assemblies are evenly distributed on a conical surface with an outer half-cone angle of 54.74° and a bottom projection of 120°. The light source assembly shares a light source with the three fiber optic ring assemblies via a 1*3 coupler. This invention eliminates the unnecessary space occupied by the traditional three independent light source configuration, reduces the overall volume, and improves optical path consistency and system stability. It can meet the engineering requirements of commercial satellite platforms for the miniaturization and mass production of inertial measurement components.

The invention discloses a long-distance distributed Brillouin optical frequency domain analysis sensing system based on an Er-doped optical fiber, the output light of an electro-optical modulator is connected with a second optical fiber coupler and is divided into two beams which are respectively used for sensing and feedback regulation, and the output light of the electro-optical modulator after feedback regulation is connected with the input of a third optical fiber coupler; the output of the gain compensation controller is connected with the other input of the third optical fiber coupler, the output of the third optical fiber coupler is connected with the input of the fourth optical fiber coupler, one output of the fourth optical fiber coupler is connected with the input of the gain compensation controller, and the other output is connected with the input of the optical fiber isolator; output light of the optical fiber isolator serves as final detection light to enter the first to-be-detected optical fiber; output light of the scrambler and output light of the second laser are input into a first erbium-doped optical fiber together through a wavelength division multiplexer, pump light enters a first optical fiber circulator after being amplified by the first erbium-doped optical fiber, one path of output light is connected to a second to-be-measured optical fiber loop provided with a second erbium-doped optical fiber, and the other path of output light is connected to input of a second circulator; one path of output of the second circulator is connected to the optical fiber reflector, and the other path of output is connected to the photoelectric detector to convert optical signals into electric signals.

The utility model discloses a kind of efficient optical fiber ring ultraviolet curing box, including box and supporting mechanism, box is closedly arranged, box is equipped with box door, multiple ultraviolet lamps are evenly spaced and arranged in ring in box;Supporting mechanism includes base disc, multiple supporting plates and power component, base disc is coaxially arranged in the lamp ring formed by all ultraviolet lamps, power component is arranged in the middle of base disc, all supporting plates are arranged around power component in ring, to form supporting ring, supporting plate and base disc are radially slidingly fitted along supporting ring, power component can make all supporting plates synchronously slide on base disc.It can solve the problem of unstable clamping during the curing process of optical fiber ring, and local curing abnormalities are prone to occur due to clamping and fixing.

The application provides a burst high-repetition-frequency tunable pulse cluster laser generating device, and belongs to the technical field of high-power microwave. The device comprises a pulse cluster laser seed module, an active optical fiber ring module, a multi-stage optical power amplification module and a multi-channel signal generation module. The technical scheme of the application realizes burst replication of the pulse cluster through the active optical fiber ring module, and outputs high-repetition-frequency tunable burst pulse cluster laser in combination with a pre-compensation technology. The output laser pulse is multi-parameter adjustable, the thermal accumulation effect of the high-repetition-frequency laser is reduced, and the continuous output problem of the instantaneous high-power laser in different application occasions is solved.

The application provides a series type optical fiber winding device, which comprises a frame body, the frame body is provided with a table board, the table board is provided with a translation sliding table assembly, the translation sliding table assembly is provided with a fiber placing assembly, a glue applying assembly and a fiber arranging rod assembly, one side of the translation sliding table assembly is provided with a fiber collecting mechanism and a skeleton end connecting assembly, the fiber collecting mechanism is internally provided with a rotatable fiber collecting driving shaft, one end of the fiber collecting driving shaft is connected with one end of an optical fiber ring skeleton, and the skeleton end connecting assembly is connected with the other end of the optical fiber ring skeleton, so that the problem that the series type narrow and long shaft optical fiber ring skeleton is difficult to be fixed on the outer side of the rotating shaft is solved.

A gyroscope shell is provided with a left cavity and a right cavity, a light source module and a power module are installed in the left cavity, an optical module is installed in the right cavity, and a curved surface groove for an optical fiber to pass through is formed between the two cavities; the optical module comprises a ring base, an optical fiber ring, a ring shell, a coupler and a Y waveguide; the optical module is reversely mounted through a screw arranged at the bottom of the gyroscope shell; the ring base and the ring shell are made of magnetic shielding materials to overcome the influence of a magnetic field on the optical fiber ring, the circuit control mainboard is fixedly connected to the ring shell, and the power panel is detachably installed on the power panel bracket. The optical fiber gyroscope provided by the invention can overcome the influence of temperature change, magnetic field and vibration impact on measurement precision and stability, and the reliability of the optical fiber gyroscope is effectively improved.

The invention discloses an event database-based optical fiber ring network fault diagnosis method and system, and the method comprises the steps: collecting the historical operation data and fault event information of an optical fiber ring network, including optical power, bit error rate, polarization state parameters, OTDR waveforms and fault processing records, and building an event database; constructing a convolutional neural network model, and performing fault feature learning and model training on the samples in the event database by using the convolutional neural network model to obtain a trained optical fiber ring network fault diagnosis model; and inputting fault data acquired in real time into the trained optical fiber ring network fault diagnosis model, performing feature matching with historical samples in the database, and identifying fault types and causes on line to obtain a diagnosis result. And the operation and maintenance efficiency, the reliability and the intelligent level of the optical fiber ring network are obviously improved.

The invention discloses a low-power-consumption high-stability optical fiber gyroscope optical path structure which comprises a temperature-control-free pump laser, a wavelength division multiplexer, an erbium-doped optical fiber, an optical fiber filter and an optical fiber reflector connected with the input end of the wavelength division multiplexer, wherein the temperature-control-free pump laser, the wavelength division multiplexer, the erbium-doped optical fiber and the optical fiber filter are connected in sequence; a first port of the optical fiber circulator is connected with the optical fiber filter, a second port of the optical fiber circulator is sequentially connected with the Y waveguide phase modulator and the optical fiber ring, and a third port of the optical fiber circulator is connected with the photoelectric detector and the optical power feedback stabilization system through the light splitting coupler. According to the invention, the non-temperature-control pump laser packaged by a flip chip and driven by temperature compensation is adopted to replace a traditional thermoelectric refrigerating unit so as to reduce power consumption, a small part of an interference signal at the output end of the circulator is extracted as monitoring light, and the driving current of the pump laser is dynamically adjusted by using an optical power feedback stabilization system, so that the monitoring precision is improved. The problem of high power consumption caused by TEC temperature control and coupler loss of a traditional optical fiber gyroscope optical path is solved, and the long-term stability of a system is improved.

The invention relates to the technical field of optical detection and optical fiber sensing, in particular to a Fabry-Perot temperature-depth sensor based on an optical fiber ring laser and a measuring system. The sensor adopts an all-fiber intracavity sensing design, and comprises a composite sensing probe formed by cascading a Fabry-Perot interferometer and a fiber bragg grating, a fiber ring laser cavity and a demodulation unit. The sensor probe is integrally packaged by adopting a three-dimensional photoetching 3D printing technology, the structure is firm, and the size is compact. According to the system, a sensing probe is embedded into a laser cavity, weak signals are amplified by utilizing gain in the cavity, and response signals of an FPI and an FBG are processed in real time based on a multi-parameter matrix algorithm in combination with stable wavelength reference and temperature reference provided by the FBG, so that high-precision synchronous measurement of temperature and hydraulic pressure (depth) and effective decoupling of cross sensitivity are realized. The optical fiber temperature-depth sensor overcomes the problems that a traditional optical fiber temperature-depth sensor is serious in cross sensitivity and poor in environmental adaptability in a complex underwater environment, has the advantages of being high in sensitivity, good in stability, high in anti-interference capacity, convenient to integrate and the like, and is suitable for the fields of ocean observation, deep sea exploration, underwater engineering safety monitoring and the like.

The application discloses a kind of based on all-fiber ultrasonic detection system and method, it is related to photoacoustic detection technical field.System includes: photo-induced ultrasonic emission module, optical ultrasonic sensing module, all-optical ultrasonic probe (3);Photo-induced ultrasonic emission module includes: pulsed laser (1), first optical fiber (2);Optical ultrasonic sensing module includes: second optical fiber (5), third optical fiber (6), fourth optical fiber (7), circulator and isolator (8), photodetector (9), tunable laser (10), acquisition card (11), computer (12);All-optical ultrasonic probe (3) includes: optical fiber ultrasonic emission group (3-1) and optical ultrasonic sensing group (3-2).The application improves probe design, optimizes manufacturing process and system structure, improves the repeatability and performance consistency of manufacture, improves the contrast and resolution of imaging simultaneously, and reduces noise interference.

The application relates to a fiber-optic gyroscope Y waveguide nonlinearity index measuring device, which comprises a light source, a fiber coupler, a measured Y waveguide, a fiber ring, a photoelectric detector, a measurement algorithm operator, a high-linearity voltage signal amplifier, a data collector and an upper computer; wherein the light source, the fiber coupler, the Y waveguide and the fiber ring are sequentially connected; the photoelectric detector is connected with the fiber coupler and the measurement algorithm operator; the high-linearity voltage signal amplifier is connected with the Y waveguide and the measurement algorithm operator respectively; the measurement algorithm operator is connected with the data collector; and the data collector is connected with the upper computer. The application can solve the problems that the Y waveguide nonlinearity index of the fiber-optic gyroscope is difficult to measure and cannot be quantitatively tested, and can effectively evaluate the quantitative relationship between the Y waveguide nonlinearity index and the threshold and scale factor nonlinearity indexes of the gyroscope.

This invention discloses a weak force sensor based on a teardrop-shaped micro / nano optical fiber and its fabrication method. The sensor comprises a biconical micro / nano optical fiber, a single-conical optical fiber, a quartz capillary tube, and a PDMS microsphere. The biconical micro / nano optical fiber is symmetrically bent, with the central waist region fiber forming a teardrop-shaped ring. The two ends of the teardrop-shaped micro / nano optical fiber ring are sequentially connected to portions of the waist region fiber, a transition region fiber, and a standard fiber. This invention utilizes the sensitive self-sensing capability of micro / nano optical fibers to achieve integrated signal input and output, greatly simplifying the measurement feedback mechanism of the sensing system and reducing overall cost. Furthermore, it is simple and intuitive to operate, reducing the technical requirements for operators. In terms of sensor fabrication, the main raw materials are standard optical fiber and quartz capillary tube, both of which are extremely low-cost. Therefore, this micro / nano optical fiber sensor exhibits significant cost-effectiveness.

The present application relates to the field of distributed optical fiber sensing, and discloses a kind of infrastructure security monitoring oriented calibration-free Raman temperature sensing device and method.The device comprises: pulse laser, the pulse laser emitted by pulse laser is sequentially incident to first calibration fiber ring, second calibration fiber ring, third calibration fiber ring and sensing fiber after wavelength division multiplexer, the Raman backward stokes scattering light and Raman backward anti-stokes scattering light generated in sensing fiber are respectively detected by two ports of avalanche photodetector, and the output end of avalanche photodetector is connected with computer through data acquisition card;The present application directly fits out calibration curve by measuring the average intensity of Raman backward anti-stokes light signal and Raman backward stokes light signal at first calibration fiber ring, second calibration fiber ring and third calibration fiber ring, realizes temperature demodulation, avoids calibration process, and improves signal-to-noise ratio and temperature measurement accuracy.

The invention belongs to the technical field of length measuring equipment, and particularly relates to an all-fiber interference type optical fiber length measuring device and method, and the device comprises a measuring table, and a torque measuring part, a micro-force measuring part, an optical fiber ring clamping part and an optical fiber winding roller which are installed on the measuring table. A rotating shaft of the torque measuring component is connected with an optical fiber ring clamping component, and an optical fiber ring is mounted on the optical fiber ring clamping component; the optical fiber winding device further comprises a balance adjusting mechanism, and the balance adjusting mechanism is installed between the optical fiber winding roller and the micro-force measuring component and used for compensating the winding tension of the optical fiber. By arranging the balance adjusting mechanism, in the optical fiber winding process, when the movement speed of an optical fiber changes due to external factors, the speed change of the optical fiber can be delayed through the displacement of the driven piece and the constant elasticity of the elastic piece, so that the winding speed and the winding tension of the optical fiber are more stable and balanced, and the winding quality of the optical fiber is improved. And the optical fiber winding quality is effectively improved.

The application provides a self-calibration high-intensity optical fiber hydrophone based on an end face reflection principle and relates to the technical field of hydrophones.The application comprises the following steps: a laser light source emits a first laser beam, a fiber optical isolator inhibits reflection and outputs a second laser beam, a fiber adjustable optical attenuator adjusts incident power and outputs a third laser beam, a 1x2 fiber coupler divides the third laser beam into a fourth laser beam and a fifth laser beam, a first photoelectric detector monitors power, a fiber circulator transmits the fifth laser beam to a fiber sensing module, generates reflected light and transmits the reflected light to a second photoelectric detector, and the second photoelectric detector converts the reflected light into a voltage signal, a data acquisition card acquires the signal, a signal demodulation processing unit calculates sound pressure sensitivity according to a mapping relationship formula of the voltage signal and the sound pressure, and a standard voltage module provides a standard voltage for the data acquisition card.The application solves the problems that a high-intensity hydrophone cannot be reused and cannot be self-calibrated after being damaged in the prior art.

The invention discloses a fiber-optic gyroscope sensitive ring module automatic bonding device and method.The fiber-optic gyroscope sensitive ring module automatic bonding device comprises a case, a Y-axis assembly, an X-axis assembly and a Z-axis assembly, the Y-axis assembly comprises a material table, a fiber-optic ring positioning and fixing seat and a magnetic shielding cover positioning and fixing seat, and the material table is slidably arranged on a working table in the Y-axis direction; the optical fiber ring positioning and fixing seat and the magnetic shielding cover positioning and fixing seat are arranged at the front end of the upper end wall of the material table, the X-axis assembly comprises a first sliding plate, the first sliding plate is arranged above the working table plate in a sliding mode in the X-axis direction, and the Z-axis assembly comprises a second sliding plate, a third sliding plate, a dispensing valve and a clamping piece. The dispensing valve is vertically arranged at the lower end of the third sliding plate, the clamping pieces are arranged at the lower end of the second sliding plate in a sliding mode in the X-axis direction, and the clamping pieces can rotate by 360 degrees along the X axis. According to the technical scheme, the bonding efficiency and precision of the sensitive ring module of the fiber-optic gyroscope can be improved, and the labor cost is reduced.

The invention provides a Sagnac type soil humidity monitoring method based on a hollow-core photonic crystal fiber. According to the Sagnac type soil humidity monitoring method based on the hollow-core photonic crystal fiber, a humidity-sensitive material is injected into the hollow-core photonic crystal fiber, a Sagnac interference structure is adopted, and high-precision measurement and efficient humidity inversion are achieved through phase modulation and eigen frequency tracking; the method comprises the following steps: injecting a humidity-sensitive material into a hollow channel of the hollow-core photonic crystal fiber; a broadband light source equally divides a light source signal into two beams of light signals through a second optical fiber coupler, one beam of light signals enters a first coupler after being subjected to polarization filtering processing through an optical fiber polarizer, the two ends of the first coupler are coupled with the two ends of a hollow-core photonic crystal fiber to form a closed optical fiber ring, and the other beam of light signals directly enters the optical fiber ring; a phase modulator is added to one arm of the first coupler, and the modulation frequency is matched with the eigenfrequency of the hollow optical fiber; and measuring the adjustment amount delta f of the frequency of the phase modulator, and calculating the soil humidity through the delta f.

The application provides a two-parameter measurement optical fiber sensor based on harmonic vernier effect and a manufacturing method, and belongs to the field of optical communication.The sensor comprises, from the incident end to the emission end, an incident single-mode optical fiber, a first multi-mode optical fiber, a first ring-core optical fiber, a third multi-mode optical fiber, a second ring-core optical fiber, a second multi-mode optical fiber and an emission single-mode optical fiber arranged in sequence.The adjacent optical fibers are fused, the cross sections of the cores of the multi-mode optical fibers are all larger than those of the adjacent other optical fibers, and the cross section of the core of the ring-core optical fiber is larger than that of the core of the single-mode optical fiber.The length of the first ring-core optical fiber is such that the reflected light of the first end face and the reflected light of the second end face form a Fabry-Perot interference, and the proportion of the first ring-core optical fiber to the second ring-core optical fiber is such that a harmonic vernier or a basic vernier is generated.The two interferometers of the sensor share the same optical fiber structure, the cascaded double chambers generate the harmonic vernier effect, the sensitivity of the sensor is improved, and the different responses of the FPI and the MZI to the external temperature and strain are utilized, so that the dual-parameter sensing function is realized.

The utility model provides a wire protection auxiliary device for winding an optical fiber ring. The wire protection auxiliary device is arranged right above a framework. The wire protection auxiliary device comprises a rake moving assembly and a rake assembly, the rake assembly is arranged on the rake moving assembly, and the rake moving assembly is used for being arranged at the corresponding position of the framework and driving the rake assembly to move; the rake assembly comprises a rake head and a rake connecting part, the two ends of the rake connecting part are connected with the rake head and the rake moving assembly respectively, and the rake head is used for extending towards the framework; one end of the rake head, which is used for extending to the skeleton, is provided with a groove, and the groove is used for abutting against the winding layer optical fiber. The grooves press the optical fibers of the winding layers, so that the optical fibers of the winding layers are located on the same horizontal plane, and the parallelism between the optical fiber layers is kept.

The invention discloses a flat low-noise multi-wavelength laser generation system and method based on a Brillouin cavity. The system comprises a multi-wavelength pumping laser generation branch, a Brillouin optical fiber ring cavity and a frequency shift injection locking branch. The multi-wavelength pumping laser generation branch is used for generating and outputting flat multi-wavelength pumping laser and comprises a first distributed feedback laser, a first polarization controller, a first optical fiber circulator, a first multi-wavelength generator and a spectrum shaper; and the Brillouin optical fiber ring cavity is connected with the multi-wavelength pumping laser generation branch and the frequency shift injection locking branch through a second circulator, and is used for generating and finally outputting multi-wavelength Brillouin laser. The invention generates multi-wavelength laser with the advantages of low noise, flat spectrum and the like, and is suitable for application scenes of low-phase noise signal generation, high-dynamic range signal processing and the like in a microwave photon system.