Acousto-optical and SAW propagation characteristics of temperature stable multilayered structures based on LiNbO₃and diamond

Theoretical studies on the surface acoustic wave (SAW) properties of c -axis oriented LiNbO 3 /IDT/diamond and diamond/IDT/128° rotated Y – X cut LiNbO 3 multilayered structures have been considered. Both layered structures exhibit a positive temperature coefficient of delay (TCD) characteristic, and a zero TCD device is obtained after integrating with an over-layer of either tellurium dioxide (TeO 2 ) or silicon dioxide (SiO 2 ). The presence of a TeO 2 over-layer enhanced the electromechanical coupling coefficients of both multilayered structures, which acts as a better temperature compensation layer than SiO 2 . The temperature stable TeO 2 /LiNbO 3 /IDT/diamond layered structure exhibits good electromechanical coefficient and higher phase velocity for SAW device applications. On the other hand, a high acousto-optical (AO) figure of merit (30–37) × 10 −15 s 3 kg −1 has been obtained for the temperature stable SiO 2 /diamond/IDT/LiNbO 3 layered structure indicating a promising device structure for AO applications.