Passive silicon-on-insulator polarization-rotating waveguides

We present preliminary experimental results for silicon-on-insulator polarization rotators with asymmetric external waveguiding layers. These devices consist of a waveguide with vertical and sloped sidewalls and are fabricated using a combination of plasma and chemical etching techniques. For a device length of 3256μm, a TE-to-TM polarization conversion efficiency of 75% was measured.