Abstract:
A doped silica-titania glass article is provided that includes a glass article having a glass composition comprising (i) a silica-titania base glass, (ii) a fluorine dopant, and (iii) a second dopant. The fluorine dopant has a concentration of fluorine of up to 5 wt. % and the second dopant comprises one or more oxides selected from the group consisting of Al, Nb, Ta, B, Na, K, Mg, Ca and Li oxides at a total oxide concentration from 50 ppm to 6 wt.%. Further, the glass article has an expansivity slope of less than 0.5 ppb/K2 at 20⃘C. The second dopant can be optional. The composition of the glass article may also contain an OH concentration of less than 100 ppm.
Abstract:
Ultralow expansion titania-silica glass. The glass has high hydroxyl content and optionally include one or more dopants. Representative optional dopants include boron, alkali elements, alkaline earth elements or metals such as Nb, Ta, Al, Mn, Sn Cu and Sn. The glass is prepared by a process that includes steam consolidation to increase the hydroxyl content. The high hydroxyl content or combination of dopant(s) and high hydroxyl content lowers the fictive temperature of the glass to provide a glass having a very low coefficient of thermal expansion (CTE), low fictive temperature (T f ), and low expansivity slope.
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 %, ΔGe≦0.12%, Δn1≦0.12%. The content of fluorine in the inner cladding layer is 0.5-1.5 wt %, Δn2≦−0.14%. The content of fluorine in the trench cladding layer is 1-3 wt %, Δn3≦−0.25%. The content of fluorine in the auxiliary outer cladding layer is 0.5-2 wt %, Δn4≦−0.14%. The outer cladding layer is a pure silicon dioxide glass layer and/or a metal-doped silicon dioxide glass layer.
Abstract:
An optical fiber containing alkali metal elements or the like in which Rayleigh scattering loss can be reduced is provided. An optical fiber includes a core composed of silica glass and a cladding which surrounds the core, has a refractive index lower than a refractive index of the core, and is composed of silica glass containing fluorine. The core contains a first group of dopants and a second group of dopants having a diffusion coefficient lower than a diffusion coefficient of the first group of dopants. The difference between the maximum value and the minimum value of residual stress in the optical fiber is 150 MPa or less.
Abstract:
An optical fiber having a reduced attenuation includes a silica glass core and a silica glass cladding. The silica glass core has substantially no germanium and includes a first core and a second core. The second core encloses the first core, the refractive index of the second core is larger than the refractive index of the first core, and the average value of halogen concentration of the second core is 5000 ppm or more. The silica glass cladding surrounds the second core and contains substantially no gemianium. The refractive index of the cladding is smaller than the refractive index of the first core.