Second leaky surface wave propagation on LiTaO3 with thin dielectric films

The propagation characteristics of the second leaky surface wave on (90°, 90°, 31°)-cut LiTaO₃ with a thin film of dielectric, such as silicon dioxide (SiO₂) and tantalum pentoxide (Ta₂O₅), are investigated theoretically and experimentally. The theoretical analysis showed that the attenuation for the metallized surface as a function of SiO₂ film thickness decreases exponentially. In fact, for the metallized surface of (90°, 90°, 31°)-cut LiTaO₃ with an RF-sputtered SiO₂ film, the measured propagation losses decreased to approximately one-third in comparison to those of the sample without the film