An experimental characterization of the grating couplers for sub-micrometer silicon-on-insulator (SOI) waveguides is presented. The grating couplers have been designed, realized, and characterized for the +1 diffraction order at an operating wavelength of 1.31 µm for TE polarization. At the resonant angle, a coupling efficiency higher than 55% has been measured. The angular coupling range and the wavelength tolerance have been evaluated to 3 • and 20 nm, respectively. The grating coupler is followed by a taper, and about 50% of the input power at 1.31 µm is coupled into sub-micrometer rib and strip SOI waveguides. The ration between light power decoupled toward the cladding and light power decoupled toward the substrate is about three.

Rib microwaveguides are demonstrated on silicon-on-insulator substrates with Si film thickness of either 380 or 200 nm and a width of 1 microm. Corner mirrors that allow compact 90 degrees turns between two perpendicular waveguides are characterized. Measured propagation losses are approximately 0.4 dB/cm and approximately 0.5 dB/cm for 380-nm and 200-nm Si film, respectively, and mirror losses are approximately 1 dB. This allows the development of applications such as optical interconnects in integrated circuits over propagation distances larger than several centimeters.