Influence of BaTiO3 ferroelectric orientation for electro-optic modulation on silicon

The influence of BaTiO3 ferroelectric domain orientations for high efficiency electro-optic modulation has been thoroughly analyzed. The Mach-Zehnder modulator structure is based on a CMOS compatible silicon/BaTiO3/silicon slot waveguide that supports both TE and TM polarizations whereas the Pockels effect is exploited by the application of a horizontal electric field with lateral electrodes placed on top of the BaTiO3 layer. The influence of the waveguide parameters has been optimized for each configuration and the lowest V-pi voltage combined with low losses has been determined. A V pi L as low as 0.27 V.cm has been obtained for a-axis oriented BaTiO3 and TE polarization by rotating the waveguide structure to an optimum angle. (C) 2015 Optical Society of America