Discrete Frequency Bragg Deflector in 2 GHz Range Using ZnO/Sapphire Substrate

A guided-wave acousto-optic (AO) Bragg deflector has been developed in 2GHz range using a single-crystal ZnO thin-film on a sapphire substrate. The ZnO thin-film was grown by RF magnetron sputtering and the propagation loss for TEo mode at 6328 1 wavelength was measured to be 1.2dB per cm. An electromechanica l coupling coefficient of 4% for t he ZnO film and a propagation loss of about 30dB per cm for the 1st-order mode (Sezawa mode) SAW were also measured. A withdrawal interdigital transducer (IDT) fabricated on thjs ZnO film has realized multiple discrete frequency responses with high Q factor. Preliminary experiments on the Bragg deflector have demonstrated discrete deflected light spots with a resolution of 3 MHz in the 2GHz range.