Analysis of Diagonal Anisotropic Electrooptic Rectangular Waveguide as an Isotropic Waveguide

A simple and accurate method for analysis of the anisotropic rectangular waveguides is presented. In this analysis the anisotropic waveguide are treated as isotropic waveguide by using the modified of both core refractive index and either waveguide thickness (with E^y _pq) or waveguide width (with E^x _pq). The anisotropic waveguide and its modified isotropic waveguide are analyzed by using first perturbation method (FPM). Also, modified waveguide is analyzed by effective index method (EIM). This study gives a simple calculation of the propagation constant and the field distribution. The effect of Z, Y and X-cuts of the electrooptic crystal are done. The accuracy by this study increases with the value of ratio n_y/n_x (with E^y _pq) or n_x/n_y (with E^x _pq) closes to one. This study is checked with important nine electrooptic materials. The numerical results with X, Y and Z-cuts of nine electrooptic materials are presented as design curves. This analysis is in very good agreement if it is compared and the finite element technique.