Electro-optic Ti:PPLN waveguide as efficient optical wavelength filter and polarization mode converter

We report the first experimental demonstration of electrically controlled Solc-type optical wavelength filters and TE-TM mode converters based on Ti-diffused periodically poled lithium niobate (Ti:PPLN) waveguides. A maximum mode conversion efficiency or a peak spectral transmittance of ~99% in the telecom C-L bands was obtained from a 9-mm long, 21.5-21.8-mum multiple-grating Ti:PPLN waveguide device with a switching voltage of as low as 22 V or 0.99 Vxd(mum)/L(cm), where d is the electrode separation and L is the electrode length. The spectral range of this device can be tuned by temperature at a rate of ~0.758 nm/ degrees C.