Subwavelength focusing of surface acoustic waves generated by an annular interdigital transducer

Vincent Laude (1) , Davy Gérard (1) , Naima Khelfaoui (1) , Carlos F. Jerez-Hanckes (1) , Sarah Benchabane (1) , Abdelkrim Khelif (1)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

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.

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]; Physique Classique [physics.class-ph]

Vincent Laude, Davy Gérard, Naima Khelfaoui, Carlos F. Jerez-Hanckes, Sarah Benchabane, et al.. Subwavelength focusing of surface acoustic waves generated by an annular interdigital transducer. Applied Physics Letters, 2008, 92, pp.094104. ⟨10.1063/1.2891055⟩. ⟨hal-00201067⟩