Sezawa wave

Special conical lenses have been developed for Lamb wave imaging of layered structures because the waves are dispersive the frequency can be varied to tune the Lamb wave angle of the specimen to the angle for which the lens is designed (Atalar and Kbymen 1989). Such lenses could similarly be used for Sezawa wave imaging and measurement, and also for other dispersive waves. It may be that for layered structures measurements of V(f) at fixed defocus will become as prevalent as V(z) (Atalar et al. 1995). 

Kushibiki, J., Chubachi, N., and Tejima, E. (1989). Quantitative evaluation of materials by directional acoustic microscope. Ultrasonics Int. 89, 736-43. [56, 149, 250] Kushibiki, J., Ishikawa, T., and Chubachi, N. (1990). Cut-off characteristics of leaky Sezawa and pseudo-Sezawa wave modes for thin-film characterization. Appl. Phys. Lett. 57,1967-9. [216]... 

Weber, A.H., Weiss, C. and Hunklinger, S. (1991) Comparison of Rayleigh and Sezawa wave modes in Zn0-Si02-Si structures. Proceedings of the IEEE Ultrasonic Symposium, 1, 363. 

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