Efficiency of guided wave acoustooptic interaction for selected cuts in LiNbO3

The efficiency of thin film acoustooptic modulators in LinNbO3 is investigated theoretically in order to select the optimum crystal cut, SAW propagation direction and optical polarization. For a well concentrated optical field x-cut LiNbO3, z-propagating SAW and TE polarized light offers best performance for broadband modulators. In the Appendix parameters of several SAWs on the free surfaces of LiNbO3 were determined by numerical analysis using acoustic field theory and the quasi static electric field approximation. Complete sets of parameters are given for calculation of SAW fields related to the magnitude of complex mechanical power flow.