Enhanced acoustical transmission and beaming effect through a single aperture

In this paper we explore from a fundamental theoretical point of view, transmission phenomena of acoustic waves transferred through a single subwavelength slit milled into a sound-hard plate that is textured by surface corrugations. It is shown that the enhanced acoustical transmission unambiguously is linked to the excitation of acoustic surface waves and Fabry-Perot modes within the aperture. With the former resonant condition, we give a prescription on how these surface waves are induced and connected to the formation of a collimated sound beam in the far field.