Method of forming waveguides with ion exchange of halogen ions

Abstract

This invention pertains to optical waveguides which includes waveguides of ll shapes and sizes, preforms, and optical fibers made from the preforms, and to a method for making waveguides devoid of a physical interface. The method includes preparation of a waveguide from a halide-containing glass, heating the waveguide to a temperature below crystallization temperature of the glass so that it is still solid, providing a gaseous reactive medium containing halide ions of higher electronegativity than halide ions in the waveguide, exposing the waveguide to said reactive medium for a sufficient duration for the halide ions of higher electronegativity in the reactive medium to replace at least a portion of the halide ions of lower electronegativity in the waveguide, and cooling the waveguide whereby a lower refractive index is formed on the side of the waveguide exposed to the reactive medium than the refractive index internally of the waveguide so that light can travel through the portion of the waveguide having the higher refractive index.

Dependencies are inferred from the claim text.