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: 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 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: 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 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 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 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 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.

Abstract: A single-mode fiber with a large effective area comprises a core layer and a cladding layer. The core layer is cladded with an intermediate cladding layer, and a depressed cladding layer is provided outside the intermediate cladding layer. The core layer comprises a first fiber sub core layer having a radius r1 of 1.5-5 ?m and a relative refractive index difference ?n1 of 0.05-0.22%, and a second sub core layer having a unilateral radial width (r2?r1) of 1.5-5 ?m and a relative refractive index difference ?n2 of 0.15-0.34%, where ?n1 is less than ?n2. Accordingly, the optical fiber can reach an effective area equal to or greater than 120 ?m2 when the related parameters thereof are optimized.

Abstract: A single-mode fiber with a large effective area comprises a core layer and a cladding layer. The core layer is cladded with an intermediate cladding layer, and a depressed cladding layer is provided outside the intermediate cladding layer. The core layer comprises a first fiber sub core layer having a radius r1 of 1.5-5 ?m and a relative refractive index difference ?n1 of 0.05-0.22%, and a second sub core layer having a unilateral radial width (r2?r1) of 1.5-5 ?m and a relative refractive index difference ?n2 of 0.15-0.34%, where ?n1 is less than ?n2. Accordingly, the optical fiber can reach an effective area equal to or greater than 120 ?m2 when the related parameters thereof are optimized.

Abstract: The invention relates to a rotary seal chuck of an optical fiber preform rod deposition lathe, comprising a fixed socket sleeve and a rotary shaft. The fixed socket sleeve is provided with a central hole base. The central hole base bears the rotary shaft through a bearing. An end of the central hole base is connected to an air hose. The rotary shaft is a hollow rotary shaft provided with a through hole. One end of the through hole communicates with the air hose, and the other end of the through hole is provided with a liner tube connecting sealing hole base. A magnetic fluid seal ring is disposed at a joint between an inner side of the rotary shaft and the central hole base of the fixed socket sleeve, to form a rotary dynamic seal. An outer side of the rotary shaft is connected to a rotary driving disk.