LONG WAVELENGTH, LOW-LOSS OPTICAL WAVEGUIDE

摘要

An optical fiber waveguide of the type comprising an outer cladding layer, an axially disposed core of SiO2 doped with GeO2 and a first inner cladding layer of SiO2 doped with an oxide such as P2O5 for lowering the preform processing temperature. A second inner cladding layer of pure SiO2 is disposed between the first inner cladding layer and the core to prevent P2O5 from diffusing into the core, thereby eliminating absorption losses from the P-O-H band in the 1.1-1.8 .mu.m region.