VARIATIONAL ANALYSIS OF DIFFUSED PLANAR AND CHANNEL WAVE-GUIDES AND DIRECTIONAL-COUPLERS

A simple and accurate analytical variational method is presented for studying the propagation characteristics of diffused planar and channel waveguides. The method gives accurate values of a normalized propagation constant for these waveguides. The method is also applied to the study of the dependence of coupling length on interwaveguide separation in diffused channel-waveguide directional couplers, and comparisons with other available theoretical results and experimental data are presented.