Open AccessModeling the anisotropic electro-optic interaction in hybrid silicon-ferroelectric optical modulator
Author(s) -
Xuan Hu,
Sébastien Cueff,
Pédro Rojo Romeo,
Régis Orobtchouk
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.001699
Subject(s) - optics , pockels effect , optical modulator , finite difference time domain method , anisotropy , permittivity , electric field , modulation (music) , lithium niobate , physics , materials science , optoelectronics , phase modulation , dielectric , acoustics , laser , quantum mechanics , phase noise
We present a numerical method to accurately model the electro-optic interaction in anisotropic materials. Specifically, we combine a full-vectorial finite-difference optical mode solver with a radio-frequency solver to analyze the overlap between optical modes and applied electric field. This technique enables a comprehensive understanding on how electro-optic effects modify individual elements in the permittivity tensor of a material. We demonstrate the interest of this approach by designing a modulator that leverages the Pockels effect in a hybrid silicon-BaTiO 3 slot waveguide. Optimized optical confinement in the active BaTiO 3 layer as well as design of travelling-wave index-matched electrodes is presented. Most importantly, we show that the overall electro-optic modulation is largely governed by off-diagonal elements in the permittivity tensor. As most of active electro-optic materials are anisotropic, this method paves the way to better understand the physics of electro-optic effects and to improve optical modulators.