AbstractWe report optical waveguiding in single-crystal, epitaxial (101) oriented rutile (TiO2) thin films grown on (1120) sapphire (α-Al2O3) substrates using the MOCVD technique. The propagation constants for asymmetric planar waveguides composed of an anisotropic dielectric media applicable to these films are derived. Modifications to the prism-film coupling theory for this anisotropic case are also discussed. By application of this model to (101) oriented rutile thin films, we directly obtain values of the ordinary and extraordinary refractive indexes, no and ne, of the rutile thin films as well as film thicknesses. We obtain typical values of the refractive indexes (no=2.5701±0.0005; ne=2.934±0.001) near to those for bulk rutile single crystals indicating the exceptional quality of these films.
Excitation of s-polarized surface electromagnetic waves in inhomogeneous dielectric media
