Integrated Optic Adiabatic Polarization Splitter on Silicon.

An adiabatic polarization splitter, fabricated with silica and silicon nitride films on a silicon substrate, is demonstrated. A rejection of the unwanted polarization (cross talk) of -20 dB to -34 dB was achieved with single filtering and -35 to -45 dB with double filtering. The device had 1.5 dB insertion loss and a very small wavelength dependence.