Propagation properties of leaky surface acoustic wave on reverse‐proton‐exchanged 10° Y‐X LiNbO 3

In this study, to reduce leaky surface acoustic wave (LSAW) attenuation, a layered structure of air/bulk LiNbO 3 (LN) layer/elastically softened LN substrate which can be fabricated by a reverse proton exchange (RPE) process was applied to 10° Y‐X LN with a larger coupling factor. First, the LSAW attenuation on a structure of air/bulk LN/modified LN was calculated with all material constants of the buried proton exchange (PE) layer taken into consideration. It was found that a condition under which the attenuation decreases as compared with the bulk value exists for the free and metallized surfaces. Next, the LSAW propagation properties were measured using IDT pairs with a 3.6‐μm wavelength on 10° Y‐X LN with the RPE layer and the buried PE layer. The propagation loss PL for the metallized surface was decreased by carrying out the RPE process from 0.44 dB/λ of a virgin wafer to 0.01 dB/λ. The decrease in PL for the shorted grating was also observed. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(3): 19–27, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/ecj.10412