Tunable Mach-Zehnder polarization splitter using height-tapered Y-branches

A tunable TE/TM polarization splitter, based on a Mach-Zehnder interferometer with an electrooptic switch, is demonstrated in GaAs-AlGaAs. Symmetric and asymmetric Y-branches employing height-tapered waveguides are used to achieve power splitting and mode sorting, respectively, in the interferometer. The device has an extinction ratio of similar to 20 dB and an excess loss less than 1.5 dB for both TE and TM polarized light, The device can be reconfigured by tuning the switching voltage for operation at both 1.3- and 1.55-mu m wavelengths.