BEND INSENSITIVE OPTICAL FIBERS WITH LOW REFRACTIVE INDEX GLASS RINGS

摘要

An optical fiber includes a silica-based glass portion having an outer diameter of less than about 120 µm. The glass portion comprises a core, an inner cladding and a low index ring. The core comprises an index of refraction n1, and a relative refractive index percent A1% relative to pure silica glass. The inner cladding surrounds the core and comprises an index of refraction n2, a radial thickness of less than about 40 µm and a relative refractive index percent ?2% relative to pure silica glass, wherein ?1% > ?2% and the difference between ?1% and ?2% is greater than 0.1%. The low index ring surrounds the inner cladding and comprises boron and fluorine, a radial thickness of less than about 20 µm, an index of refraction n3 and a third relative refractive index percent ?3% relative to pure silica glass, wherein ?2% > ?3% and ?3% is less than -0.5%.