Electro-Optic Intensity Modulator for Broadband Optical Communications

An LiNbO 3 electro-optic grating modulator, composed of coplanar microstrip electrodes with periodic small fins and an airbridge structure, is presented. The small fins slow down the microwave propagating speed, while the effect of the airbridge is the reduction of the effective index. The modulator design has good performance in terms of wavelength selection and high-speed characteristics. The microwave and optical analysis are carried out using the three-dimensional finite difference method and coupled mode equations.