Frequency dependence of the efficiency of the acoustooptic interaction of TM modes

An analysis is made of the dependence of the efficiency of the acoustooptic interaction of two guided TM modes in a diffused waveguide on the frequency of an acoustic surface wave. Calculations are made for model waveguides having a Gaussian profile function, supporting different numbers of modes, and also for a real waveguide fabricated by diffusion of titanium into lithium niobate. The results of the calculations are compared with the experimental data. An analysis is made of the difference between the frequency dependences of the TM_m – TM_n and TE_m – TE_n interactions.