Germanium-free optical fibers having large numerical apertures

• Main Authors: JOORMANN; HENDRIK J. M, SPIERINGS; GIJSBERTUS A. C. M
• Format: Patent
• Language: English
• Published: 04.03.1986
• Edition: 4
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; METALLURGY; MINERAL OR SLAG WOOL; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

An optical fiber of germanium-free, multicomponent glasses has a core glass which has the molecular composition: SiO2: 57.5-65%; (ZrO2+1/2Y2O3): 0-5%; (MgO+CaO+SrO+BaO+ZnO): 12.5-27.5 where MgO: 0-5%, CaO: 0-10%, SrO: 0-7.5%, BaO: 0-15% ZnO: 0-20%, and in which if no BaO is present, the ZnO content is 12.5-20%, and if no ZnO is present, the BaO content is 5-15%, and (Li2O+Na2O+K2O): 10-25%. The core glass has a K2O content which is preferably smaller than half of the total alkali metal oxide content. The cladding glass consists of a silicate glass or a borosilicate glass having a refractive index which is at least 2% lower than the refractive index of the core glass. The viscosity of the cladding glass at the processing temperature is 0.5 to twice the viscosity of the core glass expressed in Pa.s.