Abstract

Devices constructed with interdigitated surface electrodes are widely used in integrated optics to produce electrooptic switches, deflectors, and modulators as well as to launch surface acoustic waves. To be able to fabricate devices with the desired characteristics, it is essential to know the electric field that is produced in the material under the interdigitated electrodes. The spatial distribution of the electric field produced by a voltage applied to a set of interdigitated electrodes on the surface of an anisotropic crystal such as lithium niobate is calculated using rigorous electromagnetic theory. The effects of the electrode width, period, and thickness are presented. Variations with crystal orientation are analyzed. The presence of a buffer layer such as isotropic silicon dioxide is included and the effects of its thickness are presented. The resulting distributions of refractive index and strain are calculated and analyzed in terms of amplitude and harmonic content.

© 1985 Optical Society of America