Intrinsic Optical Losses of GeO2–P2O5–Al2O3Glasses for Optical Fibers

Abstract

Intrinsic optical losses of GeO2–P2O5–Al2O3glasses considered as potential materials for low-loss optical fibers have been investigated. Rayleigh scattering (at 488 nm wavelength) and infrared absorption tailing of GeO2–P2O5–Al2O3glasses were measured using silica glass as a standard. Rayleigh scattering losses of 10–20 mol% P2O5–GeO2glasses were as low as those of pure GeO2glass. Addition of 1–2 mol% Al2O3improves the stability against crystallization and chemical durability with a slight increase of Rayleigh scattering. The minimum loss of GeO2glasses containing below 20 mol% P2O5is estimated to be 3×10−2–1×10−1dB/km, which is between the values of silica glass (∼10−1dB/km) and GeO2glass (3×10−2dB/km).