Electro-Optical Modulation Based on Pockels Effect in BaTiO3 With a Multi-Domain Structure

The influence of an in-plane multi-domain structure in BaTiO
₃
films grown on SrTiO
₃
/Si buffers for highly efficient electro-optic modulation has been analyzed. The modulation performance can be significantly enhanced by rotating a certain angle, the optical waveguide, with respect to the BaTiO
₃
crystallographic axes. A robust electro-optical performance against variations in the domain structure as well as the lowest V
_π
voltage can be achieved by using the rotation angles between 35° and 55°. Our calculations show that V
_π
voltages below 1.7 V for a modulation length of 2 mm can be obtained by means of a CMOS compatible hybrid silicon/BaTiO
₃
waveguide structure.