SILICON-ON-INSULATOR OPTICAL RIB WAVE-GUIDE LOSS AND MODE CHARACTERISTICS

Optical rib waveguides with rib heights of 3.17 and 7.67 microns with various widths have been formed in separation by implantation of oxyge n (SIMOX) based silicon-on-insulator (SOI) structures. The effect of w aveguide rib etch depth, width, and interface roughness on loss and mo de characteristics have been studied at wavelengths of 1.15 and 1.523 microns. The experimental results support the hypothesis that certain rib dimensions can lead to single mode SOI waveguides even though plan ar SOI waveguides of similar multimicron dimension are not single mode . Mode loss was found to be strongly dependent on interface roughness and mode confinement.