A planar photonic crystal waveguide based on the semiconductor-on-insulator (SOI) materials system is analyzed theoretically. Two-dimensional (2-D) calculations and comparison with dispersion relations for the media above and below the finite-height waveguide are used to obtain design guidelines. Three-dimensional (3-D) calculations are given for the dispersion relations and field profiles. The field profiles obtained using 2-D and 3-D calculations are qualitatively similar. However, we find that compared with 2-D calculations, the frequencies of the guided modes are shifted and the number of guided modes changes. The theoretically predicted frequency intervals, where the waveguide supports leakage-free guidance of light, are compared with an experimental measurement for propagation losses. Two out of three frequency intervals coincide with low-measured propagation losses. The poor guidance of light for the third frequency interval is explained theoretically by investigating the vertical localization of the guided modes.
Thomas Søndergaard, Jesper Arentoft, and Martin Kristensen, "Theoretical Analysis of Finite-Height Semiconductor-on-Insulator-Based Planar Photonic Crystal Waveguides," J. Lightwave Technol. 20, 1619- (2002)