Use of generalized parameters to describe acoustooptic interaction in a diffused waveguide

An analysis is made of the dependence of the efficiency of the Bragg acoustooptic interaction between $TE$ modes in a diffused optical waveguide on the acoustic surface wave frequency. It is found that two waveguides having different optical parameters, but supporting the same number of modes, are described by almost the same frequency dependences. This conclusion is confirmed by calculations for two fourmode waveguides utilizing $Y$-cut lithium niobate. The frequency dependences of various processes were measured experimentally in the range 50-550 MHz.