LiNbO 3 broadband interferometric optical modulators: modeling and implementation

Abstract

An accurate and yet simple simulation technique for optical modulators operating at multi-GHz region and optical modulators are critical for Tera-bps optical communications. This paper describes a simple, efficient and accurate analysis of the traveling wave electrodes for high speed optical modulation and the implementation of these electrodes in interferometric optical modulators. A finite difference approach is employed in modeling the traveling wave electrodes for efficient electro-optic interaction in interferometric optical modulators. Electrode configurations such as symmetric and asymmetric co-planar waveguide or strip structures and shielded electrode systems can be modeled. Simulated results demonstrate the efficiency of the presented method as compared with other methods such as the Green's function, conformal mapping, method if images, spectral domain analysis etc. Tilted and thick practical electro-plated electrodes are modeled and confirmed with implemented modulators operating up to 26 GHz in diffused LiNbO3 optical interferometric optical waveguide structures. The fabrication of optical waveguides and traveling wave electrodes are described for implementation of the electro-optic interferometric modulators.