General analysis of electrodes in integrated-optics electrooptic devices

Integrated-optics electrooptic devices that rely on the electrooptic effect obtained by applying electric waves on the electrodes deposited on the light waveguides are considered. A general structure for the devices is presented, and a computational method for calculating the electric-field distribution in the structure is described. Comparisons between numerical and exact results are made in cases with a known solution. The effect of the thickness of the electrodes is investigated. The characteristic impedance and effective dielectric constant are presented as a function of the electrode thickness for various width-gap ratios of the electrode structure. Calculations show that the electric field in the substrate is slightly influenced by the electrode thickness, whereas the characteristic impedance and effective dielectric constant are decreased as the electrode thickness is increased