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.

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.

Abstract: A single mode fiber having a core, an inner cladding, a depressed cladding, and an outer cladding composed of pure silica glass. The core is surrounded in sequence with the inner cladding and the depressed cladding. The core has silica glass doped with germanium and fluorine, with a diameter (a) of 8.0-8.8 ?m, a relative refractive index difference (?1) of 0.35-0.38%, and the contribution of fluoride (?F) is ?0.09±0.02%. The inner cladding has silica glass doped with germanium and fluorine, with a diameter (b) of 18-21 ?m and a relative refractive index difference (?2) of 0±0.02%. The depressed cladding has silica glass doped with fluorine, with a diameter (c) of 26-36 ?m and a relative refractive index difference (?32) at the external interface thereof is between ?0.22 and ?0.35%, and a relative refractive index difference (?31) at the internal interface thereof is between ?0.20 and ?0.35%, and ?32??31.

Abstract: A multimode fiber including a core and a cladding. The core has a radius (R1) of 24-26 ?m, the refractive index profile thereof is a parabola, and the maximum relative refractive index difference (?1) is 0.9-1.1%. The cladding surrounds the core and includes from inside to outside an inner cladding, a middle cladding, and an outer cladding; a radius (R2) of the inner cladding is 1.04-1.6 times that of the core, and a relative refractive index difference (?2) thereof is ?0.01-0.01%; the middle cladding is a graded refractive index cladding whose radius (R3) is 1.06-1.8 times that of the core, and a relative refractive index difference thereof is decreased from ?2 to ?4; and a radius (R4) of the outer cladding is 2.38-2.63 times that of the core, and a relative refractive index difference (?4) thereof is between ?0.20 and ?0.40%.