Abstract
Acoustic lenses are used to focus sound in the same way that optical lenses focus light. In this paper, it is showed that an acoustic lens can be built with a single subwavelength slit surrounded by a finite number of grooves. The model of this lens as well as numerical results of acoustic wave focalization by means Finite Element Method at frequencies around 1700 Hz are also presented. The focusing ability of this structure depends on the geometrical parameters such as groove depth. Thus, the focal length of this acoustic lens can be adjusted by varying the groove depth. Therefore, it is possible to modify the focus position without increasing the the size of the structure
