Systematic study of acoustic surface modes and their acousto-optic coupling in LiNbO/sub 3/ and LiTaO/sub 3/

A program that searches arbitrary cuts of a specified material for true and approximate acoustic surface mode solutions has been used to provide identification of the optimal acoustooptic cuts of LiNbO/sub 3/ and LiTaO/sub 3/ for integrated acoustooptic devices such as acoustooptic tunable filters. SAW (surface acoustic wave) and STW (surface transverse wave) modes have been analyzed on a class of cuts of LiNbO/sub 3/ and LiTaO/sub 3/ which maximize the material birefringence, minimizing the ultimate device size. This search has yielded ranges of orientations which show strong acoustooptic coupling to SAW modes, but has shown no useful STW solutions on these materials. In particular, the plotted results show that, for this restricted range of orientations, X-cut Y-propagating LiNbO/sub 3/ is a cut which has near-optimal acoustooptic power requirements and optimal electromechanical coupling.<
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