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AssigneeSchott Glas
InventorsRalf Domres, Norbert Wolfram Gehenn, Uwe Kolberg, Georg Krolla, Frank Thomas Lentes
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The stepped optical fiber has a core glass member and a surrounding cladding glass member. It has a high numerical aperture (NA)≧0.50. The core glass member preferably has a zinc-containing composition including, in % by weight, SiO2, 42 to 53; ZnO, 16 to 38; PbO, 1 to 20; Na2O, <14; K2O, <12; with a sum of ZnO and PbO≧30 and a sum of Na2O and K2O is ≧2. The cladding glass composition, which is compatible with this core glass, includes, in percent by weight, SiO2, 60 to 72; B2O3, <20; Al2O3, <10; Na2O, <18; and K2O, <15. The resulting optical fiber has low attenuation, very neutral color transmission and low manufacturing costs. Other cladding glass compositions resulted in considerably poorer properties with too much crystallization at the core glass boundary layer. Environmentally-friendly, lead-free embodiments of the core glass were also prepared having even lower aperture values of ≧0.48.
A stepped optical fiber from multicomponent glass, said stepped optical fiber having a numerical aperture ≧0.50 and comprising a core glass member and a cladding glass member, said cladding glass member completely surrounding said core glass member, wherein said core glass member has a core glass composition, which comprises
A stepped optical fiber from multicomponent glass, said stepped optical fiber having a numerical aperture ≧0.48 and comprising a core glass member and a cladding glass member, said cladding glass member completely surrounding said core glass member, wherein said core glass member has a core glass composition, which comprises
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