Use of a Prism Coupler for the Determination of the Index Profiles of Ion-Exchanged Channel Waveguides

The K+-Na+ ion-exchange process (IEP) has long been recognized as an attractive technique for producing high-quality, low loss, graded refractive index (GRIN) optical waveguides in glass substrates. Devices produced by this technique are index compatible with silica fibers, and as a result, this technology has received considerable attention as a means of producing low-insertion loss integrated optic devices for use in fiber communications networks.1 Accurate design of such devices, generally comprised of one or more channel waveguides, requires a thorough characterization of the waveguide-forming process. Although planar K+-Na+ IEP waveguides have been studied extensively2, to date however, only limited characterization of channel waveguides has been performed.