Coupling anomalies in Si_mGe_n/Si/SiO_2 waveguide systems

Abstract

Sharp coupling anomalies exist in a SiGe superlattice buried in a silicon-on-insulator waveguide structure. We study these anomalies using a rigorous coupled wave analysis and examine their suitability for silicon- compatible waveguide-mode resonant filters for optical telecommunications. Active functions could include optical detection, switching, and modulation. We predict that a very weak, sub band-edge absorption can improve filter contrast or provide high quantum efficiency detection.