The Effects of Strain on Electromagnetic Modes of Anisotropic Dielectric Waveguides at p-n Junctions

A first order -perturbation expansion is carried out in order to analyze the effect of small spatially uniform, strains on the lowest order (even) TE and TM modes in an anisotropic dielectric waveguide. This generalizes the results of an earlier paper in which the effects of certain special cases of uniform strain were calculated. Unlike in these special cases, the perturbed modes are, in general, neither purely TE or TM, and one effect of two of the offdiagonal components of the strain is to tilt the plane of polarization and change the relative phase of the two polarizations. To first order, the modes are not exponentially attenuated. Some numerical examples are considered in order to illustrate the results. It is found that, under appropriate conditions, the effect of the small strain may be quite large in relation to its magnitude.