Abstract: A high-bandwidth bend-insensitive multimode fiber includes a core laver and a cladding including an inner cladding, a depressed cladding, and an outer cladding arranged sequentially from inside to outside. The core layer is a silicon dioxide glass layer co-doped with germanium, phosphorus (P), and fluorine (F) and has a refractive index profile in a shape of a parabola, a distribution index in a range of 2.0-2.3, a radius in a range of 23-27 ?m, and a maximum relative refractive index difference in a range of 0.9-1.2% at its center. A contribution amount of P at the center is in a range of 0.01-0.30%. A doping amount of F increases from the center to the edge of the core layer. A contribution amount of F at the center and edge of the core layer is in range of 0.0% to ?0.1%, and ?0.40% to ?0.20%, respectively.

Abstract: A polarization-maintaining multi-core fiber includes a plurality of fiber core areas and a main outer cladding. The fiber core areas include one central fiber core area, and two or more than two outer fiber core areas equidistantly and uniformly arranged around the central fiber core area that is a polarization-maintaining fiber core area. Each outer fiber core area includes a fiber core and an inner cladding surrounding a core layer. A portion outside the fiber core areas is the main outer cladding. The fiber can greatly enhance spectral efficiency of an optical transmission system, and improve fiber communication capacity. The arrangement of the polarization-maintaining fiber core area provides a waveguide structure with a function of maintaining polarized light, which can be used for transmission of local light.

Abstract: A low-dispersion single-mode fiber includes a core and claddings covering the core. The core layer has a radius in a range of 3-5 ?m and a relative refractive index difference in a range of 0.15% to 0.45%. The claddings comprise a first depressed cladding, a raised cladding, a second depressed cladding, and an outer cladding arranged sequentially from inside to outside. The first depressed cladding has a unilateral width in a range of 2-7 ?m and a relative refractive index difference in a range of ?0.4% to 0.03%. The raised cladding has a unilateral width in a range of 2-7 ?m and a relative refractive index difference in a range of 0.05% to 0.20%. The second depressed cladding has a unilateral width in a range of 0-8 ?m and a relative refractive index difference in a range of 0% to ?0.2%. The outer cladding is formed of pure silicon dioxide glass.

Abstract: An array-type polarization-maintaining multi-core fiber includes a main outer cladding, fiber core units, and stress units. The fiber core units and the stress units are arranged to form a unit array including one central unit and any unit in the unit array being equidistantly arranged from adjacent units thereof. Provided is at least one pair of stress units, each pair of stress units being arranged symmetrical about one fiber core unit to form a polarization-maintaining fiber core unit. The fiber core units each include a fiber core and an inner cladding surrounding a core layer. A portion outside the fiber core units and the stress units is the main outer cladding. The fiber can greatly enhance spectral efficiency of an optical transmission system, and improve fiber communication capacity.

Abstract: A low-dispersion single-mode optical fiber includes a core and a cladding covering the core. The core has a relative refractive index difference of 0.30-0.65% and a radius of 2.5-4.5 ?m. The cladding layer including first, second, third cladding layers and an outer cladding arranged sequentially from inside to outside. The first cladding layer covers the core, and has a relative refractive index difference of ?0.70% to ?0.30% and a radius of 4.5-7.5 ?m. The second cladding layer covers the first cladding layer, and has a relative refractive index difference of ?0.20% to 0.25% and a radius of 7.0-12.0 ?m. The third cladding layer covers the second cladding layer, and has a relative refractive index difference of ?0.60% to 0.00% and a radius of 10.0-20.0 ?m. The outer cladding covers the third cladding layer, and is a layer made of pure silicon dioxide glass.

Abstract: A rare earth-doped double-clad optical fiber includes a rare earth ion-doped fiber core, an inner cladding layer, and an outer cladding layer. A cross section of the inner cladding layer is a non-circular plane including at least two arcuate notches. According to the provided optical fiber, optical processing can be performed on a preform without changing a preform preparation process and a drawing process. The inner cladding is designed to have a non-circular planar structure having a cross section with at least two arcuate notches. While maintaining the same light absorption efficiency of pump light within the cladding layer, a preform polishing process is simplified, a risk of cracking the preform during polishing of multiple surfaces and a risk of contamination of the preform caused by impurities are reduced, wire drawing control precision is better, and comprehensive performance of the optical fiber is improved.

Abstract: A high bandwidth radiation-resistant multimode optical fiber includes a core and a cladding layer surrounding the core. The core is a fluorine-doped quartz glass layer with a graded refractive index distribution and a distribution power exponent ? of 1.7-2.2. The core has R1 of 15-35 ?m and ?1%min of ?0.8% to ?1.2%. The cladding layer has an inner cladding layer having R2 of 15-38 ?m and ?2% of ?0.8% to ?1.2% and/or a depressed inner cladding layer having R3 of 15-55 ?m and ?3 of ?1.0% to ?1.4%, an intermediate cladding layer having R4 of 15.5-58 ?m and ?4 of ?0.7% to ?0.2% a depressed cladding layer hasving R5 of 16-60 ?m and ?5 of ?0.8% to ?1.2%, and an outer cladding layer sequentially formed from inside to outside. The outer cladding layer is a pure silica glass layer.

Abstract: An anti-cracking panda-type polarization-maintaining optical fiber includes a cladding layer, stress layers, and a fiber core. The fiber core is located in the center of the cladding layer. The stress layers are located symmetrically at two sides of the fiber core with a distance away from the fiber core and are located within the cladding layer. Each stress layer is enclosed at edges of their outer sides by a transition layer with a gradient refractive index. By providing the transition layer with the gradient refractive index at the edge of the outer side of the stress layer, the pressure stress at the edge of the stress layer is decomposed and released, so as to avoid cracks at the edge of the polished stress layer on the end of the optical fiber, and thus optimizes the performance of the polarization-maintaining optical fiber by decreasing the room temperature polishing cracking rate.

Abstract: A small core-diameter graded-index optical fiber include a core layer and a cladding having an inner cladding layer, a depressed cladding layer, and an outer cladding layer from inside to outside thereof. The core layer has a parabolic refractive index profile with a distribution index in a range of 1.9-2.1, a radius in a range of 10-21 ?m, and a ?1 max in a range of 0.7-1.7% at a core layer center, and is a silica glass layer co-doped with germanium, phosphorus, and fluoride. The inner cladding layer is a pure silica layer or an F-doped silica glass layer, and has a unilateral width in a range of 0.5-5 ?m and a ?2 in a range of ?0.4-0%. The depressed cladding layer has a unilateral width in a range of 2-10 ?m and a ?3 in a range from ?0.8% to ?0.2%. The outer cladding layer is a pure silica glass layer.

Abstract: A multimode optical fiber includes a core and a cladding covering the core. The core has a radius in a range of 23.75-26.25 ?m. A refractive index profile of the core has a graded refractive index distribution with a refractive index distribution index ? in a range of 1.80-1.89. The core has a maximum relative refractive index difference ?1% in a range from 1.0% to 1.15%. The multimode optical fiber has a fusion loss less than or equal to 0.08 dB. The multimode optical fiber is applied in a middle-and-long distance distributed temperature-measuring system, and a temperature-measuring distance of the system reaches 10 km to 27 km. The system includes a pulsed laser light source, a wavelength division multiplexer, an avalanche photodiode, a data acquisition device, an upper computer, and the temperature-measuring multimode optical fiber.

Abstract: A fused-biconical-taper bend-insensitive single mode optical fiber includes a core and a cladding. The core is a fluorine-germanium co-doped silicon-dioxide quartz glass layer, a diameter Dcore thereof is 7-10 ?m, and a relative refractive index difference ?1 thereof is 0.20% to 0.40%. A range of ?Ge is 0.30% to 0.60%, and a range of ?F is ?0.05% to ?0.15%. The cladding includes three layers. A first layer is a fluorine-germanium co-doped silicon-dioxide quartz glass layer, a relative refractive index difference ?31 thereof is ?0.02% to ?0.10%, and a diameter D31 thereof is 15-30 ?m. A second layer is a fluorine-doped silicon-dioxide quartz glass layer, a relative refractive index difference ?32 thereof is ?0.01% to ?0.05%, and a diameter D32 thereof is 30-50 ?m. A third layer is a pure silicon-dioxide quartz glass layer, and a diameter D33 thereof is 124-126 ?m.

Abstract: A single-mode fiber with ultralow attenuation includes a core layer and cladding layers. The cladding layers includes an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary cladding layer. The core layer has a radius of 3.9-4.8 ?m and a relative refractive index difference of ?0.08% to 0.10%. The inner cladding layer has a radius of 9-14 ?m and a relative refractive index difference of ?0.40% to ?0.15%. The trench cladding layer has a radius of 13-25 ?m and a refractive index difference of ?0.7% to ?0.3%. The auxiliary outer cladding layer has a radius of 30-50 ?m and a relative refractive index difference of ?0.4% to ?0.15%. The outer cladding layer is a pure silicon dioxide glass layer.

Abstract: A high-bandwidth bend-insensitive multimode optical fiber includes a core and a cladding. A refractive index profile of the core has a parabola shape and a distribution index thereof is ?. The core has a radius of 23-27 ?m. A maximum relative refractive index difference of a central position of the core is 0.9%-1.2%. The core is a germanium-fluorine co-doped silicon dioxide glass layer. The central position of the core has a minimum amount of fluorine doped, and a mass percentage of fluorine content is CF,min. A mass percentage of fluorine content of the core changes with the radius according to a function. The cladding successively comprises an inner cladding, a trench cladding, and an outer cladding from inside to outside. The optical fiber reduces bandwidth-wavelength sensitivity while improving bandwidth performance; is compatible with existing OM3/OM4 multimode optical fibers, and support wavelength-division multiplexing technology in a wavelength range of 850-950 nm.

Abstract: An optical fiber with ultra-low attenuation and large effective-area includes a core layer and cladding layers. The cladding layers have an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary outer cladding layer. The core layer has a radius of 4.8-6.5 ?m, and a relative refractive index difference of ?0.06% to 0.10%. The inner cladding layer has a radius of 9-15 ?m, and a relative refractive index difference of about ?0.40% to ?0.15%. The trench cladding layer has a radius of about 12-17 ?m, and a relative refractive index difference of about ?0.8% to ?0.3%. The auxiliary outer cladding layer has a radius of about 37-50 ?m, and a relative refractive index difference of about ?0.6% to ?0.25%. The outer cladding layer is a pure silicon-dioxide glass layer.

Abstract: An optical fiber with ultra-low attenuation and bend insensitivity includes a core layer and cladding layers. The cladding layers have an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary outer cladding layer. The core layer has a radius of 3.0-3.9 ?m, and a relative refractive index difference of ?0.04% to 0.12%. The inner cladding layer has a radius of 8-14 ?m, and a relative refractive index difference of about ?0.35% to ?0.10%. The trench cladding layer has a radius of about 14-20 ?m, and a relative refractive index difference of about ?0.6% to ?0.2%. The auxiliary outer cladding layer has a radius of about 35-50 ?m, and a relative refractive index difference of about ?0.4% to ?0.15%. The outer cladding layer is a pure silicon-dioxide glass layer.

Abstract: A doping optimized single-mode optical fiber with ultra low attenuation includes a core layer and cladding layers. The cladding layers has an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary outer cladding layer. The content of fluorine in the core layer is ?0.5 wt %, ?Ge?0.12%, ?n1?0.12%. The content of fluorine in the inner cladding layer is 0.5-1.5 wt %, ?n2??0.14%. The content of fluorine in the trench cladding layer is 1-3 wt %, ?n3??0.25%. The content of fluorine in the auxiliary outer cladding layer is 0.5-2 wt %, ?n4??0.14%. The outer cladding layer is a pure silicon dioxide glass layer and/or a metal-doped silicon dioxide glass layer.

Abstract: A bending-insensitive single-mode fiber with ultralow attenuation includes a core layer and cladding layers. The cladding layers includes an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary cladding layer. The core layer has a radius of 3.0 to 3.9 ?m and a relative refractive index of ?0.04% to 0.12%. The inner cladding layer has a radius of 8 to 14 ?m and a relative refractive index ?0.35% to ?0.10%. The trench cladding layer has a radius of 14 to 20 ?m and a relative refractive index of ?0.6% to ?0.2%. The auxiliary outer cladding layer has a radius of 35 to 50 ?m and a relative refractive index of ?0.4% to ?0.15%. The outer cladding layer is a pure silica glass layer.

Abstract: A single-mode fiber with an ultra-low attenuation and a large effective area includes a core layer having a radius of 4.8 to 6.5 and a relative refractive index difference ?n1 of ?0.06% to 0.10%, and cladding layers. The cladding layers includes an inner cladding layer surrounding the core layer, a trench cladding layer surrounding the inner cladding layer, an auxiliary outer cladding layer surrounding the trench cladding layer, and an outer cladding layer surrounding the auxiliary cladding layer. The inner cladding layer has a radius of 9 to 15 ?m and a relative refractive index difference of ?0.40% to ?0.15%. The trench cladding layer has a radius of 12 to 17 ?m and a relative refractive index difference of ?0.8% to ?0.3%. The auxiliary outer cladding layer has a radius of 37 to 50 ?m and a relative refractive index difference of ?0.6% to ?0.25%. The outer cladding layer is a pure-silicon-dioxide glass layer.

Abstract: A light intensity adjustable ultraviolet device for curing an optical fiber coating includes a cylindrical mounting base; a UVLED light source module mounted along a peripheral direction and an axial direction in an inner cavity of the cylindrical mounting base; a cylindrical focusing lens configured in front of a light emitting surface of the UVLED light source module, so that ultraviolet light emitted by the UVLED light source module is focused on a curing axis; and an ultraviolet sensor mounted in the inner cavity of the cylindrical mounting base, wherein the ultraviolet sensor is connected to a UVLED power supply control module via an ultraviolet intensity signal processing module; the UVLED power supply control module is connected to the UVLED light source module, so that an optical fiber drawing speed and an ultraviolet intensity form a control closed loop.

Abstract: A bend-insensitive multimode optical fiber includes a core layer, and cladding layers surrounding the core layer. The core layer has a parabolic refractive index profile with ? being 1.9-2.2, a radius being 23-27 ?m, and a maximum relative refractive index difference being between 0.9-1.2%. The inner cladding layer has a width being 1-3 ?m and a relative refractive index difference being between ?0.05% and 0.1%. The trench cladding layer has a width being 2-5 ?m and a relative refractive index difference being between ?1% and ?0.3%. The core layer is a Ge/F co-doped silica glass layer, where an F doping contribution at a central position of the core layer is less than or equal to 0%, an F doping contribution at an edge portion of the core layer is greater than or equal to ?0.45%. The outer cladding layer is a pure silica glass layer.