Two-step ion-exchanged waveguides with high surface refractiveindices are fabricated under a variety of conditions. By modifying theconventional two-step ion exchange, the losses and the effective diffusiondepth can be decreased without a significant effect on the surfacerefractive index. The influence of the first step, K+ –Na+ ion exchange,performed time dependably on the surface refractive index change isinvestigated. Energy-dispersive x-ray spectroscopy is performed to establish the diffusion profiles of various ions
