SINGLE MODE OPTICAL FIBER WITH ULTRA-LOW ATTENUATION AND BEND INSENSIBILITY

摘要

A single mode optical fiber with ultra-low attenuation and bend insensibility for an optical communication transmission system, comprises a core layer and a cladding layer. The core layer has a radius r1 of 3.0-3.9 micrometers and a relative refractive index difference Delta n1 of -0.04% to 0.12%. The core layer is coated inside-to-outside orderly with an inner cladding, a depressed inner cladding, an auxiliary outer cladding and an outer cladding. The inner cladding has a radius r2 of 8-14 micrometers and a relative refractive index difference Delta n2 of -0.35% to -0.10%, the depressed inner cladding has a radius r3 of 14-20 micrometers and a relative refractive index difference Delta n3 of -0.6% to -0.2%, the auxiliary outer cladding has a radius r4 of 35-50 micrometers and a relative refractive index difference Delta n4 of -0.4% to -0.15%, and the outer cladding is a pure silica glass layer. Alkali metal doping is added into the core layer to optimize core layer viscosity. The fiber not only has a low attenuation coefficient and an excellent bending performance, but also can be compatible with the G657.A2 standard. The fiber manufacturing cost is low.