Low loss glass and optical fibers therefrom

Abstract

Optical fibers and glass composition comprising a mixture of barium oxide, gallium oxide, germanium oxide, and a modifying agent selected from lanthium oxide, indium oxide, and mixtures thereof; molar ratio of barium oxide to gallium oxide is from about 4:1 to about 1:1, preferably 2:1 to 1, and especially about 1:1; amount of germanium oxide is at least 40 mole percent, preferably 60 to 95 mole percent, and especially 65 to 90 mole percent; about 0.1 to about 5 mole percent, preferably 0.5 to 4, of gallium oxide is replaced with the modifying agent. The optical fibers made from the glass composition defined herein, with or without the modifying agent, have light transmission wavelength band of about 0.3 to 4 microns; lower optical loss than silica-based optical fibers, the minimum optical loss of the novel fibers having the potential of 0.05 dB/km at 2 microns.