52 results about "Bare fiber" patented technology

The invention discloses a cladding light stripper, a manufacturing method thereof and an optical fiber laser, and relates to the technical field of cladding light strippers, the cladding light stripper comprises a double-cladding optical fiber assembly and a three-cladding bare fiber, the double-cladding optical fiber assembly comprises two sections of double-cladding optical fibers, each double-cladding optical fiber comprises a double-cladding bare fiber and a coating layer which are sequentially arranged from inside to outside in a sleeved mode, and the three-cladding bare fiber is arranged between the double-cladding bare fiber and the coating layer. The double-cladding bare fiber extends out of the coating layer; the number of the three-cladding bare fibers is multiple sections, the multiple sections of three-cladding bare fibers are sequentially welded to form a main body, the two sections of double-cladding optical fibers are welded to the two ends of the main body through the double-cladding bare fibers respectively, and a stripper is formed on the main body. According to the cladding light stripper, on the premise that the original advantages of a double-cladding optical fiber and a three-cladding bare fiber are kept, multiple sections of three-cladding bare fibers are adopted to manufacture the stripper, so that the situation that a certain section of three-cladding bare fiber bears high power for a long time to generate local hot spots can be prevented, and the cladding light stripping capacity of the cladding light stripper is greatly improved.

The invention belongs to the technical field of beam combiner packaging, and discloses a beam combiner heat dissipation packaging method, which can enable the packaging of an optical fiber bundle to be simpler and low in cost by adopting a shell structure only comprising a placement piece and a sleeve, and can enable the packaging of the optical fiber bundle to be more stable by gradually coating low-refractive-index glue of which the refractive indexes are gradually increased on a bare fiber of an output single fiber of the optical fiber bundle of the beam combiner. When the optical fiber coating layer is coated with the high-refractive-index glue, pyrogenic light leaked to the output single-fiber coating layer is dispersed in advance and is not completely concentrated on the subsequent optical fiber coating layer, so that the heating and burning risks of the optical fiber are effectively reduced, and meanwhile, the temperature of the optical fiber coating layer is further effectively reduced by coating the coating layer with the high-refractive-index glue, and the service life of the optical fiber coating layer is prolonged. Therefore, temperature stabilization and effective heat dissipation of the output single fiber are realized.

The invention discloses a reusable embedded metal-coated short-gate long fiber bragg grating temperature sensor, which comprises a small-size metal-coated fiber bragg grating and a bare fiber bragg grating which are matched with each other and are simultaneously embedded into a structure to be measured, and is characterized in that the small-size metal-coated fiber bragg grating comprises a short-gate long fiber bragg grating, an optical fiber transition section and a tail fiber; the surface of the gate region part of the short-gate long fiber bragg grating is coated with a metal coating layer, the optical fiber transition sections are arranged on the two sides of the short-gate long fiber bragg grating, and the tail fiber is connected with the optical fiber transition sections. The small-size metal-coated fiber bragg grating is obtained through chemical plating, insulation pretreatment and electroplating, and then temperature and strain coefficients are obtained through calibration by an embedded method. According to the sensor, embedded monitoring is achieved, and meanwhile the problems that large initial damage is caused to embedded materials by existing metal sleeve packaging, and multi-point temperature monitoring cannot be achieved by single-head sleeve packaging are solved.

The invention discloses an automatic core aligning structure of an optical fiber fusion splicer, which relates to the technical field of optical fiber fusion splicers and comprises a fusion splicer body, a mounting frame is arranged above the fusion splicer body, a fiber aligning driving mechanism is arranged in the mounting frame, and a windproof cover is arranged above the fusion splicer body; and a core alignment supporting assembly. When the windproof cover is closed, a pushing and extruding arm presses a power-assisted arm rod, so that a sealing plug plate is pressed downwards to push air in an air storage cavity to be filled into an arc-shaped wrapping bag, the arc-shaped wrapping bag wraps an optical fiber, and the diameters of different optical fibers can be supported through wrapping of the arc-shaped wrapping bag; when the optical fiber is uniformly wrapped by the arc-shaped wrapping bag, pressure distribution is soft, vibration can be absorbed, protectiveness is good, bare fiber damage is effectively avoided, if dust is attached to the surface of the arc-shaped wrapping bag, through flexible self-adaptive compensation of the arc-shaped wrapping bag, dust tolerance is higher, deviation of the optical fiber due to dust is reduced, and the service life of the optical fiber is prolonged. And the phenomenon of inaccurate core alignment is avoided.

The invention relates to an optical fiber drawing method integrated with a coloring function and a production system, and relates to the technical field of optical fiber manufacturing, and the method comprises the following steps: melting and drawing an optical fiber preform to form a bare fiber; the bare fiber is cooled; coating the cooled bare fiber twice to form an inner coating and an outer coating; performing primary UV curing on the inner coating and the outer coating to enable the outer coating to reach a semi-cured state; coating coloring ink on the surface of the outer coating in a semi-cured state; performing secondary UV curing on the coloring ink, so that the coloring ink is cured, and the inner coating and the outer coating are finally cured; and the cured optical fiber is detected and taken up. The coloring procedure is integrated into the wire drawing process, integrated continuous production is achieved, and optical fiber microbend loss caused by multiple times of winding and unwinding is avoided; by means of molecular activity in a semi-cured state, coloring ink permeates to form an interpenetrating network structure, and adhesive force is improved.

A colored optical fiber comprises a bare optical fiber, a primary layer formed of a first ultraviolet curing resin covering the bare optical fiber, and a secondary layer formed of a second ultraviolet curing resin covering the primary layer, wherein a Young's modulus of the primary layer is smaller than 70% with respect to a saturated Young's modulus of the primary layer, and wherein the saturated Young's modulus of the primary layer is smaller than or equal to 0.85 MPa.

The invention relates to the technical field of optical fiber communication, in particular to a bare fiber FAU grinding clamp which comprises a clamp body, a fixing sleeve is arranged below the clamp body in a piston inserting mode, a rotating seat is rotationally connected to the fixing sleeve, an adjusting seat is arranged above the rotating seat, and a transmission mechanism is fixedly connected to one side of the adjusting seat. One end of the transmission mechanism is rotatably connected with the movable frame, the movable frame is rotatably connected with the turnover seat, the turnover seat is fixedly connected with the plurality of automatic locking mechanisms, and the problems that the operation difficulty is high and the consistency cannot be effectively ensured in the prior art are solved through fine assembly of the extension size of the optical fiber; the grinding angle of the extending bare fiber is ensured, and the difficulty of FA assembly is greatly reduced), and meanwhile, the extending angle of the FA bare fiber is ensured, so that the coupling precision is higher, the output power is stable, and the material loss caused by vertical inconsistency of FA assembly is greatly reduced.

1. Name of this product design: Winding Fiber Optic Storage Tray. 2. Purpose of this design: For winding and storing bare optical fibers, armored optical fibers, and other optical fibers. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: 3D view 1.

The utility model relates to a high tensile strength pre-embedded optical fiber quick connector, which comprises a main body, the left side of the main body is provided with a V-shaped groove piece, the front side of the V-shaped groove piece is provided with a cover plate, the bottoms of the V-shaped groove piece and the cover plate are provided with locking sheets, the V-shaped groove piece and the cover plate are fixedly connected through the locking sheets, and the top of the V-shaped groove piece is sleeved with an opener. According to the utility model, the embedded first cable locking piece and the second cable locking piece are adopted, and the first cable locking piece and the second cable locking piece are provided with zigzag occlusion structures, so that the requirement of high tensile strength between various optical cables and connectors can be met, the maximum tensile strength can meet 120N and is far higher than 60N of similar products, the copper U-shaped locking sheet design is adopted, the bare fiber locking force meets 4N, and the tensile strength is greatly improved. And the product reliability is better, the embedded structure is adopted, the whole structure of the product is compact, the length is only 53 mm, the production process is simple, and the production cost is low.

A cladding light stripper and a manufacturing method therefor, and an optical fiber laser, relating to the technical field of cladding light strippers. The cladding light stripper (100) comprises a double-clad optical fiber assembly (1) and triple-clad bare fibers (2); the double-clad optical fiber assembly (1) comprises two sections of double-clad optical fibers (11), each double-clad optical fiber (11) comprises a double-clad bare fiber (111) and a coating layer (112) which are concentrically arranged in sequence from inside to outside, and the double-clad bare fiber (111) extends out of the coating layer (112); there are multiple sections of triple-clad bare fibers (2), the multiple sections of triple-clad bare fibers (2) are sequentially welded to form a main body (3), the two sections of double-clad optical fibers (11) are respectively welded to two ends of the main body (3) by means of the double-clad bare fibers (111), and a stripper is formed on the main body (3). The cladding light stripper (100) can be constructed from multiple sections of triple-clad bare fibers (2) while preserving the original advantages of the double-clad optical fibers (11) and the triple-clad bare fibers (2); this design can avoid the formation of local hot spots in any section of triple-clad bare fiber (2) due to prolonged high-power operation, thereby significantly improving the cladding light stripping ability of the cladding light stripper (100).

This application discloses a method for enhancing the quality of bare fiber sensing signals in vehicle-mounted vibration environments. It relates to the field of fiber optic sensing signal quality enhancement, and utilizes a multi-axis inertial measurement unit and a vibration sensing network to construct a spatiotemporal feature tensor, enabling three-dimensional dynamic perception of the vibration environment. Filtering parameters and gain are dynamically configured based on vibration characteristics to ensure stable signal acquisition under strong vibration conditions. A deep feature decoupling network, combined with vibration environment information, effectively separates noise from the target signal, improving the signal-to-noise ratio. A dynamic compensation module, based on a physical heuristic model, corrects vibration-induced transmission distortion from three dimensions: polarization state, birefringence, and microbending loss, ensuring the physical integrity of the signal. A closed-loop collaborative control mechanism dynamically optimizes the parameters of each module through real-time signal quality feedback, forming an adaptive optimization closed loop. Through spatiotemporal multi-dimensional collaborative processing, high-quality and robust enhancement of bare fiber sensing signals in vehicle-mounted vibration environments is achieved.

The invention belongs to the technical field of optical fiber sensors, and discloses a preparation device for a miniature optical fiber gap sensor, which comprises a machine table, and the machine table is provided with a height visual guiding mechanism, a left bare fiber adjusting mechanism, a right bare fiber adjusting mechanism, a visual monitoring mechanism and a horizontal visual guiding mechanism. The invention discloses a preparation method for a miniature optical fiber gap sensor, and the preparation method comprises the following preparation steps: S1, starting up; s2, fixing a probe bracket; s3, positioning a probe bracket; s4, optical fiber positioning; s5, performing optical fiber collimation; s6, micro-control dispensing is carried out; and S7, ending. By using the device and the method provided by the invention, precise installation of the probe bracket and the bare fiber probe can be completed.

The utility model relates to a bare fiber strain-wavelength relation calibration device, comprising a slide rail provided with main scale marks, the slide rail is provided with a fixed slide block, a movable slide block and a limiting slide block in sequence, the fixed slide block, the movable slide block and the limiting slide block are all screwed with set screws, the movable slide block is provided with vernier scale marks, the vernier scale marks are provided with vernier scales, and the vernier scales are provided with vernier scales. The fixed sliding block and the movable sliding block are provided with optical fiber fixing clamps, the end side, facing the limiting sliding block, of the movable sliding block is pulled through a pull rope, and the other end of the pull rope is connected with a weight. The optical fiber calibration device solves the problems that a special calibration device is lacked in the optical fiber calibration process, optical fiber stress is inconvenient, and calibration errors are large. A traditional optical fiber calibration method is very easy to cause tensile failure and damage of an optical fiber and cannot realize accurate force application measurement. According to the device, the possibility of simply and accurately calibrating the optical fiber is realized, and compared with other equipment and test methods, the flexibility and the convenience are greatly improved.

This utility model relates to a bare optical fiber polishing fixture, including a polishing jig and a positioning jig. The polishing jig includes a positioning plate, an upper pressure plate, and a lower base plate stacked sequentially. The positioning plate has an optical fiber positioning groove extending through its front and rear ends. The optical fiber positioning groove is formed by an array of bare fiber grooves for accommodating bare optical fibers. The upper pressure plate is located at the upper part of one end of the positioning plate and is attached to the positioning plate to clamp the bare optical fiber. The lower base plate is located at the lower part of one end of the positioning plate and is attached to the positioning plate to support the positioning plate. The polishing jig is placed on the positioning jig to position the length of the bare optical fiber extending out of the polishing jig. This utility model, through the cooperation of the polishing jig and the positioning jig, not only enables multiple optical fibers to be fixed simultaneously in the polishing jig for overall clamping, improving clamping stability, but also reduces the risk of easy breakage of the end of a single optical fiber due to friction from the polishing paper, thereby improving the polishing efficiency of bare optical fibers.

The application discloses a method for inhibiting stimulated Brillouin scattering of a single-frequency fiber laser gain fiber, which comprises the following steps: stripping the coating layer of the gain fiber to obtain a bare fiber, wiping the bare fiber clean, and then positioning the two ends of the bare fiber by clamping the two ends of the bare fiber with a fiber clamp; heating the bare fiber by moving step by step according to a fixed length of moving interval from one end to the other end along the axial direction of the bare fiber; and increasing one or both of the temperature and the time of heating step by step after each movement, or decreasing one or both of the temperature and the time of heating step by step. The method for inhibiting stimulated Brillouin scattering of a single-frequency fiber laser gain fiber provided by the application can adjust the gradient distribution of the doped ions in the gain fiber by controlling the heating temperature, the heating time and the heating position direction parameters in a heat diffusion manner, and can broaden the Brillouin gain spectrum in the gain fiber while keeping the highest temperature of the gain fiber basically unchanged.

The utility model relates to an optical fiber coating layer cleaning device which comprises two optical fiber clamping mechanisms for clamping optical fibers and a cleaning electric sliding table moving in the length direction of the optical fibers, a stripping mechanism driving air cylinder and a cleaning mechanism driving air cylinder are installed on a moving portion of the cleaning electric sliding table, a stripping mechanism is installed on the stripping mechanism driving air cylinder, and a cleaning mechanism is installed on the cleaning mechanism driving air cylinder. A cleaning mechanism is installed on the cleaning mechanism driving air cylinder and comprises a cleaning support and a cleaning pneumatic clamping jaw fixedly connected to the cleaning support, cleaning jaws are fixedly connected to two clamping fingers of the cleaning pneumatic clamping jaw, two cloth strip frames are installed on the cleaning support, and the cloth strip frames are fixedly connected to the cleaning pneumatic clamping jaw. According to the optical fiber cleaning device, the optical fiber is clamped through the cloth strips, the bare fiber position of the optical fiber is subjected to friction cleaning, the cleaning effect is improved by spraying alcohol, the cloth strips are moved through the air cylinder, and therefore the optical fiber is cleaned through the clean cloth strips all the time. And the cleanliness of the bare fiber is improved, so that the subsequent melting operation is facilitated.

To provide an optical fiber core wire with high water resistance even under low loads where delamination may occur.SOLUTION: There is provided an optical fiber core wire including: an optical fiber bare wire; a primary layer which coats the optical fiber bare wire and is formed of a first ultraviolet curable resin; and a secondary layer which coats the primary layer and is formed of a second ultraviolet curable resin. When a load is applied to the optical fiber core wire perpendicular to its longitudinal direction, delamination occurs at a load of 330 g or less with a ratio of 50%. When the optical fiber core wire is immersed in 60°C warm water for 200 days, delamination does not occur.SELECTED DRAWING: Figure 1

The invention provides a manufacturing process and device of a carbon coating optical fiber. The manufacturing process of the carbon coating optical fiber comprises the following steps: coating the surface of a bare optical fiber and forming a first coating; carbonizing the first coating in an inert gas environment so as to convert the first coating into a carbon coating; and coating the surface of the carbon coating and forming a second coating. According to the technical scheme, the problem that when the carbon-coated optical fiber is produced by adopting the mode in the prior art, the reaction gas may be burnt and exploded under the hot oxygen condition can be solved.

Disclosed is a method (600) for drawing an optical fiber (124) comprising step of melting a cylindrical glass preform (118) in a draw furnace (102) to obtain a bare optical fiber (120), cooling the bare optical fiber inside a cooling tube (106), supplying at least one inert gas inside the cooling tube (106) from at least one inlet port (208), recovering the at least one inert gas from at least one recovery port (214) that is positioned at an intermediate position along a longitudinal axis (218) of the cooling tube (106) and coating the cooled bare optical fiber (120) to obtain the optical fiber (124).

The invention provides an optical fiber drawing tower wire drawing device which comprises a controller, a driving part, a moving part, an optical fiber diameter measuring part, an auxiliary wire drawing wheel set and a main wire drawing wheel, the auxiliary wire drawing wheel set and the main wire drawing wheel are sequentially arranged from top to bottom, and the auxiliary wire drawing wheel set comprises two auxiliary wire drawing wheels which are connected to the moving part; the moving part is used for driving the two auxiliary wire drawing wheels to get close or away; the optical fiber diameter measuring piece is used for measuring diameter data of the bare fiber penetrating in or out of the auxiliary wire drawing wheel set; according to the fiber drawing tower fiber drawing device provided by the invention, the diameter size of a bare fiber penetrating into the auxiliary fiber drawing wheel set is measured by arranging the fiber diameter measuring piece, and the controller sends a control command to the moving piece according to the diameter size information of the bare fiber collected by the fiber diameter measuring piece; therefore, the two rotating auxiliary wire drawing wheels are driven by the moving part to adjust the distance in real time and get away from each other to be separated from a bare fiber after reaching the specified diameter of the bare fiber, so that the wire drawing efficiency of the optical fiber is improved, the abrasion of the belt of the auxiliary wire drawing wheels is reduced, and the wire drawing size stability of the optical fiber is improved.

This invention discloses an integrated method and tooling for precise fiber stripping and online strength testing of optical fibers, relating to the field of optical fiber device manufacturing and testing technology. The method includes: fixing the optical fiber to a dedicated tooling; pushing the tooling so that its first limiting part abuts against the stripping fixture of a fiber stripping machine, mechanically determining the stripping length and performing the stripping; transferring the tooling to an integrated testing device without disassembly, applying standardized bending stress to the bare fiber; and determining the quality based on the fracture condition. The tooling includes a base with a first limiting part and a mounting groove, an assembly block with a groove, and a clamping block with a second limiting part. The arc-shaped surfaces of the two limiting parts restrict the bending amount. This invention fundamentally eliminates the influence of equipment accuracy on the stripping length through mechanical limiting, achieves online non-destructive full inspection of micro-cracks through standardized bending stress, and completes two processes in a single clamping operation through the tooling, significantly improving the accuracy, efficiency, and reliability of optical fiber connector manufacturing.

The present invention proposes a fiber optic self-monitoring FRP rod and a fiber stripping method thereof, belonging to the field of intelligent structural materials. This invention solves the problem of existing self-monitoring FRP bars / rods that it is difficult to simultaneously ensure high fiber bonding performance and convenient fiber stripping. The fiber optic self-monitoring FRP rod comprises a bare optical fiber, a thermoplastic tight jacket layer, and a thermosetting FRP layer. The bare optical fiber is coated with a thermoplastic tight jacket layer, which is then coated with a thermosetting FRP layer. The thermosetting FRP layer comprises fibers and a thermosetting resin. The fibers are impregnated with the thermosetting resin, then wrapped around the thermoplastic tight jacket layer and subjected to a pultrusion process to form the thermosetting FRP layer. It is primarily used for structural health monitoring.

To provide an optical fiber core wire and a method for manufacturing an optical fiber core wire which can set the Young's modulus and elongation at break of a primary layer to be appropriate values.SOLUTION: An optical fiber core wire includes an optical fiber bare wire, a primary layer which covers the optical fiber bare wire and is formed of a first ultraviolet curable resin, and a secondary layer which covers the primary layer and is formed of a second ultraviolet curable resin, wherein the primary layer has a crosslinking point derived from an unsaturated carbon bond and a crosslinking point derived from a silane coupling agent, and the primary layer contains 0.014 wt.% or more and 0.72 wt.% or less of a silicon atom.SELECTED DRAWING: Figure 1

The invention provides a coating device of a high-temperature-resistant metal coating optical fiber and a using method, and relates to the technical field of optical fiber coating devices.The coating device comprises a coating mechanism, the coating mechanism comprises a mold, the mold comprises a mold barrel, a coating cavity and a mold core, the coating cavity is arranged in the mold barrel, and the mold core is arranged in the coating cavity; the mold core comprises a mold core cavity and a feeding hole, the mold core cavity is formed in the mold core, the feeding hole is formed between the mold core cavity and the coating cavity and enables the mold core cavity and the coating cavity to be communicated, the mold core cavity is cylindrical, and the height of the mold core cavity can be adjusted; the mold core further comprises an upper fiber penetrating hole and a lower fiber penetrating hole, the lower fiber penetrating hole is formed under the upper fiber penetrating hole, the upper fiber penetrating hole and the lower fiber penetrating hole are both communicated with the mold core cavity, and the coating thickness and quality can be controlled by adjusting the height of the mold core cavity; the position of the lower bottom surface of the mold core cavity is adjusted, the thickness of the metal coating coated outside the bare fiber can be accurately controlled, and the lower the position of the lower bottom surface of the mold core cavity is, the smaller the thickness of the metal coating of the coated optical fiber is; bubbles in the metal solution can be controlled by adjusting the position of the upper bottom surface of the mold core cavity; the higher the position of the upper bottom surface of the mold core cavity is, the smaller the probability that bubbles appear in the metal solution in the mold core cavity is, the higher the uniformity of the metal coating of the produced optical fiber is, and the better the quality is.

The invention discloses an in-operation OPGW fiber core strain safety threshold calculation method and system, and relates to the technical field of optical cable fiber core strain. According to the technical key points, the method comprises the following steps: determining the maximum allowable strain value of an OPGW cable body based on a cable body stress and fiber core strain correlation model obtained through simulation under a reference working condition without other additional loads; determining the maximum bearing strain value of the OPGW cable body based on a cable body stress and fiber core strain correlation model obtained by simulation under the working condition of icing load; under the steady-state working condition of considering the creep effect, the corresponding relation between the icing thickness and the fiber core strain is designed based on the maximum icing value, then the OPGW fiber core strain increment after the icing load is overlaid is calculated according to the corresponding relation, and the OPGW fiber core steady-state safety threshold value is determined by combining the quantitative relation between the operation age limit and the optical cable excess length and the OPGW fiber core strain increment caused by icing. According to the method, the limitation of a traditional single bare fiber strain threshold value is broken through, and a safety evaluation model closer to engineering practice is established.

An optical connector includes a ferrule having a fiber hole, a plurality of optical fibers that are inserted into the fiber hole, and an adhesive that fixes the plurality of optical fibers to the ferrule. Each of the plurality of optical fibers has a bare fiber and a coating that partially covers the bare fiber, a portion of the bare fiber that is exposed from the coating has a small diameter portion that is located inside the fiber hole and a large diameter portion that has a larger diameter than the small diameter portion, an injection hole for injecting the adhesive is not formed in a region of the ferrule orthogonal to a longitudinal direction of the fiber hole from the small diameter portion, and an injection hole is formed in a region of the ferrule orthogonal to the longitudinal direction from the large diameter portion.

The invention provides special wire drawing equipment and method for preparing a fiber bragg grating. The equipment comprises a wire drawing furnace and an ultraviolet exposure system which are sequentially arranged from high to low, melting the optical fiber preform into a bare fiber by a fiber drawing furnace, and inscribing a grating on the bare fiber by an ultraviolet exposure system; the sensibilization system is arranged between the wire drawing furnace and the ultraviolet exposure system; the sensibilization system comprises an oxyhydrogen blast burner used for forming oxyhydrogen flames, and the formed oxyhydrogen flames are aligned with the grating inscribing area in the bare fiber for sensibilization treatment. According to the invention, the sensitization system is additionally arranged between the fiber drawing furnace and the grating inscribing system, hydrogen and oxygen are combusted to form oxyhydrogen flame, and the bare fiber which is just fused into the fiber is subjected to sensitization treatment, so that the photosensitivity of the grating inscribing area is improved, and the preparation of the fiber grating with high reflectivity is further realized.

The present disclosure relates generally to a fiber holder for holding optical fibers. The fiber holder can include a main holder body having a length that extends between first and second ends of the main holder body, a width that extends between first and second side walls of the main holder body, and a height that extends between top and bottom sides of the main holder body. The main holder body can define a plurality of fiber positioning grooves that extend along the length of the main holder body and spaced across the width of the main holder body. The main holder body also includes a fiber engagement structure having a fiber engagement surface. The fiber engagement structure can be aligned with an open region that interrupts the plurality of fiber positioning grooves. The fiber engagement structure can extend through the height of the main holder body from the top side to the fiber engagement surface.

The utility model discloses a coal mine tunnel deformation monitoring sensor based on a fiber bragg grating. The fiber bragg grating sensor comprises a polyvinyl chloride tube and a bare fiber bragg grating, the polyvinyl chloride tube is located at a hollow part in the bare fiber bragg grating, end fixing blocks are fixedly arranged at two ends of the polyvinyl chloride tube, and an optical signal converter and a fiber bragg fiber gyroscope are fixedly arranged in the polyvinyl chloride tube and on the outer wall of the polyvinyl chloride tube respectively. According to the utility model, the polyvinyl chloride pipe provided with the bare fiber grating is fixed in the groove on the roadway pavement through the end part fixing block and the horizontal fixing base, and then the groove is poured and backfilled by using concrete, so that the polyvinyl chloride pipe can be driven to bend through the deformation of the pavement; the deformation is recorded and the wavelength change of the bare fiber bragg grating is measured through the fiber bragg fiber gyroscope, the deformation condition of the roadbed can be accurately measured, compared with a traditional monitoring mode, the monitoring mode is more hidden and is not prone to external interference, and meanwhile the pavement deformation condition can be stably monitored for a long time.

The present disclosure relates generally to a bare fiber connection system that includes first and second multi-fiber fiber optic connectors that have a retractable shroud with a pivotal locking member mounted thereon. The pivotal locking member can be configured to lock the retractable shroud in an extended position. The pivotal locking member can be pivoted about a pivot point while remaining attached to the retractable shroud to unlock the retractable shroud such that the retractable shroud can move to a retracted position.