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: 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 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: 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.

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.

Abstract: A plasma resonant cavity, including a cylindrical resonant cavity casing, cutoff waveguides, and a waveguide inlet circumferentially formed on the cylindrical resonant cavity casing. The cutoff waveguides are arranged at two ends of the cylindrical resonant cavity casing and employ a movable end cover structure. An intermediate through hole is formed on each cutoff waveguide with the movable end cover structure, and a raised round table is arranged on an inner end surface of the cutoff waveguide and configured with the resonant cavity.