Acousto-Electro-Optic Effects in SAW Devices

Both acoustooptic (AO) and electrooptic (EO) interactions can be generated simultaneously in piezoelectric crystals to produce an acousto-electrooptic (AEO) effect. AO devices have been developed for performing convolution, correlation, and matched filtering; EO devices may be used for pulse compression and matrix processing, as well as many other applications. An AEO effect can give not only an additional port for information, but also overcome individual limitations and be used for all the above applications. A theoretical description of AEO interaction in the Bragg regime, based on superposition of surface acoustic waves (SAW) and EO interdigital transducers was reported previously.1 Longitudinal and transverse components of the propagating SAW and applied electric field were considered separately to account for the anisotropy of the crystals. Coupled mode theory was then applied to predict features of the resulting diffraction.