Complementary metal oxide semiconductor compatible silicon-on-insulator optical rib waveguides with local oxidation of silicon isolation.

摘要

The Local Oxidation of Silicon (LOCOS) technique is used for the first time to define optical rib waveguides in silicon-on-insulator (SOI) material. Optical mode simulation was used to determine rib geometries suitable for single-mode propagation in the 1550 nm optical telecommunications band. Test devices were then fabricated in SOI material with a Si film thickness near 3 mum. Cut-and-etchback optical testing of 3 mum drawn width ribs showed the loss to be less than 1 dB/cm at 1555 nm. Unbalanced Mach-Zehnder interferometers with Y-splitter junctions were also fabricated and tested with input wavelength swept from 1470 to 1580 nm and showed an extinction of 6-10 dB, demonstrating the ability of the LOCOS rib technique to produce more complex waveguide devices.