SOME EFFECTS OF ANISOTROPY ON PLANAR ANTIRESONANT REFLECTING OPTICAL WAVE-GUIDES

In this paper, propagation characteristics of some planar antiresonant reflecting optical waveguides (ARROW's) comprised of anisotropic medi a are studied using an integral equation approach, The integral equati on method is rigorous and general, with the added advantage that multi ple layers of crystalline material with arbitrary anisotropy can be ac commodated in a straightforward manner, The integral equation method i s applied to study basic propagation characteristics of the ARROW stru cture where one or more dielectric layers are allowed to be anisotropi c. Practically, the presence of anisotropy may be unintentional, due t o material fabrication or processing techniques, or it may be intentio nally utilized to allow integration of anisotropy-based devices and wa veguiding structures on a single semiconducting substrate, Propagation characteristics and field distributions are shown for a uniaxially an isotropic ARROW where the material's optic axis is rotated in each of the three principal geometrical planes of the structure. It is found t hat even moderately large levels of anisotropy do not significantly af fect the propagation characteristics of the ARROW if either the optic axis of the material is aligned with one of the geometrical axes of th e waveguide, or if the optic axis is rotated in the equatorial plane, In these cases, pure TE(0) modes can propagate, resulting in a low-los s structure, In the event of misalignment between the geometrical axes and the material's optic axis in the transverse or polar planes, the influence of even small levels of anisotropy is quite pronounced, In t his case, pure TE(0) modes do not exist, and attenuation loss increase s significantly due to the hybrid nature of the fundamental mode.