We propose and demonstrate experimentally the concept of the annular interdigital transducer that focuses acoustic waves on the surface of a piezoelectric material to a single, diffraction-limited, spot. The shape of the transducing fingers follows the wave surface. Experiments conducted on lithium niobate substrates evidence that the generated surface waves converge to the center of the transducer, producing a spot that shows a large concentration of acoustic energy. This concept is of practical significance to design new intense microacoustic sources, for instance for enhanced acouto-optical interactions.
Cite
@article{arxiv.0712.3899,
title = {Annular interdigital transducer focuses piezoelectric surface waves to a single point},
author = {Vincent Laude and Davy Gérard and Naima Khelfaoui and Carlos F. Jerez-Hanckes and Sarah Benchabane and Abdelkrim Khelif},
journal= {arXiv preprint arXiv:0712.3899},
year = {2013}
}