Electro-optic modulation in LiNbO3 ridge type integrated optical waveguides

An analytical basis for evaluating electro-optic modulators and predicting their performance as phase modulators is proposed. In particular, the wave-guide geometry chosen is a ridge type with a rectangular cross-section. The central core consists of LiNbO3 which is melted and re-crystalized on LiTaO3. Air forms the upper boundary with the LiNbO3 while metal clad walls are assumed for the sides. The two metals used in the analysis are gold and aluminum. Approximate mode solutions for the optical boundary value problem are developed and the results used to explore several specific designs. Primary emphasis is placed on predicting speed, physical size, required drive power, insertion loss, and required drive voltage. Comparisons to available experimental data are made.