Surface acoustic waves in proton‐exchanged lithium niobate and lithium tantalate

The use of surface acoustic waves in integrated optical devices seems to be very promising for applications in modern telecommunication and data processing technologies. The studies of surface acoustic wave propagation in lithium niobate and lithium tantalate with optical waveguides formed by the proton exchange technique are reported here. The influence of protonated layer parameters on the SAW propagation characteristics is investigated for various crystal cuts and waveguide fabrication conditions. The acoustic velocity and attenuation have been studied by the laser probe method. The effective electromechanical coupling coefficient of the protonated crystal surface has been measured by the method of thin metal film evaporation. Possibilities for controlling both the optical and acoustic properties of proton‐exchanged waveguides by the post‐exchange annealing have been studied. The results of experimental studies of SAW propagation parameters are compared with those of theoretical calculations performed ...