Modeling the anisotropic electro-optic interaction in hybrid silicon-ferroelectric optical modulator

Area of Science:

• Photonics and Materials Science
• Computational Electromagnetics

Background:

• Electro-optic effects are crucial for optical modulators.
• Anisotropic materials exhibit complex electro-optic responses.
• Accurate modeling of electro-optic interactions is essential for device optimization.

Purpose of the Study:

• To present a numerical method for modeling electro-optic interactions in anisotropic materials.
• To enable a comprehensive understanding of how electric fields modify the permittivity tensor.
• To design and optimize an electro-optic modulator using this method.

Main Methods:

• Combined a full-vectorial finite-difference optical mode solver with a radio-frequency solver.
• Analyzed the overlap between optical modes and applied electric fields.
• Investigated the Pockels effect in a hybrid silicon-Barium Titanate (BaTiO3) slot waveguide.

Main Results:

• Demonstrated accurate modeling of electro-optic effects in anisotropic materials.
• Achieved optimized optical confinement in the BaTiO3 layer.
• Designed travelling-wave index-matched electrodes for efficient modulation.
• Showed that off-diagonal elements of the permittivity tensor significantly govern electro-optic modulation.

Conclusions:

• The presented numerical method provides a comprehensive understanding of electro-optic effects in anisotropic materials.
• This technique is vital for improving the design and performance of optical modulators.
• The study highlights the importance of off-diagonal permittivity tensor elements in electro-optic modulation.