Electro-Optical Modulation Based on Pockels Effect in BaTiO₃With a Multi-Domain Structure

Abstract

The influence of an in-plane multi-domain structure in BaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> films grown on SrTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> crystallographic axes. A robust electro-optical performance against variations in the domain structure as well as the lowest V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">π</sub> voltage can be achieved by using the rotation angles between 35° and 55°. Our calculations show that V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">π</sub> voltages below 1.7 V for a modulation length of 2 mm can be obtained by means of a CMOS compatible hybrid silicon/BaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> waveguide structure.