Thin-film acoustooptic devices

Many thin-film acoustooptic interaction experiments for Bragg modulators and deflectors, for mode converters, and for fast switches have been demonstrated. Due to the high-power density, long interaction length, and controllable dispersion associated with guided-wave structures, thin-film acoustooptic devices have proved to have advantages over their bulk wave counterparts. In this paper, thin-film acoustooptic devices are discussed in terms of 1) the unique features in theoretical calculations which arise from the use of guided-wave structures, 2) the possible device configurations which may improve efficiency and speed, 3) the thin-film material and fabrication problems, 4) the transducer efficiency bandwidth trade-off, and 5) a comparison with bulk acoustooptic devices and thin-film electrooptic devices. Recent experimental results for thin-film acoustooptic modulators and convolvers are included.