Patent ID: 8312743
Filing Date: 2012-11-20
Classification: C03C,G02B

Abstract:
1. A method for forming an optical waveguide in a substrate having first and second surfaces, the method comprising the steps of: (a) an ion-exchange to form a waveguide in said first surface of said substrate at a predetermined ion-exchange temperature, wherein the substrate is exposed to an external source of ions, and wherein a surface waveguide is formed; (b) forming an electrode on said first and second surfaces of said substrate; and (c) carrying out a field-assisted annealing step on said substrate to move said waveguide from said first surface deeper into said substrate to form a buried waveguide, wherein the peak of the refractive index of said buried waveguide is below said first surface, said method comprising only one exposure of the substrate to an external source of ions.