Second leaky surface wave propagation on LiTaO/sub 3/ with thin dielectric films

The propagation characteristics of the second leaky surface wave on (90/spl deg/, 90/spl deg/, 31/spl deg/)-cut LiTaO/sub 3/ with a thin film of dielectric, such as silicon dioxide (SiO/sub 2/) and tantalum pentoxide (Ta/sub 2/O/sub 5/), are investigated theoretically and experimentally. The theoretical analysis showed that the attenuation for the metallized surface as a function of SiO/sub 2/ film thickness decreases exponentially. In fact, for the metallized surface of (90/spl deg/, 90/spl deg/, 31/spl deg/)-cut LiTaO/sub 3/ with an RF-sputtered SiO/sub 2/ film, the measured propagation losses decreased to approximately one-third in comparison to those of the sample without the film.