Thin-film acousto-optic interaction in linbo₃

100% Bragg diffraction of guided optical waves by surface acoustic waves in metal-diffused layers in LiNbO3 substrates has been observed. The predicted efficiency, which compares favourably with experimental measurement, is shown to arise mainly from the electro-optic contribution of the electric field associated with the yz acoustic surface waves instead of the elasto-optic contribution due to the strain or from the surface ripple components. © 1974, The Institution of Electrical Engineers. All rights reserved.