Methods to reduce optical loss of an ar waveguide

Abstract

Methods for modifying the interface of optical substrates. To achieve desirable optical properties, surface defects need to be removed from the interface layer. In one example, a substrate is exposed to an ion beam then a high temperature bake or laser annealing to correct the interface layer. In another example, a high energy ion beam can be used to remove the interface layer then a new interface layer can be added during a high temperature bake or laser annealing with a protective layer added last. If not removed surface defects in the interface layer may absorb a percentage of light in a single interaction. In a waveguide, light may bounce ten to hundreds of times inside a substrate causing significant light loss. Therefore, removing the surface defects significantly increases waveguide efficiency.