Wavelength-tunable electrooptic polarization conversion in birefringent waveguides

Wavelength-tunable, electrooptic polarization conversion in a birefringent waveguide accomplished with a multiple cascade of alternating TE from to TM mode converter and TE/TM phase shifter sections is analyzed. Such polarization converters have been demonstrated in LiNbO/sub 3/ and have been used as electrooptically tunable narrowband ( Delta lambda <or= lambda /sub 0//1000) wavelength filters with tuning ranges of at least lambda /sub 0//200. It is shown that the polarization converter requires only two independent drive voltages and provides arbitrary polarization transformations from any general input polarization to any desired output polarization with simultaneous wavelength tunability. The device is characterized by its overall transfer matrix and the optical bandwidths and tuning ranges for various electrode geometries.