Subwavelength imaging of acoustic waves by a canalization mechanism in a two-dimensional phononic crystal

In this letter, the subwavelength imaging of acoustic waves is reported based on a mechanism that the evanescent modes of a source are canalized by the Bloch modes of a two-dimensional phononic crystal that served as the lens. The phononic crystal was designed to have a thickness that meets the condition of Fabry–Pérot resonance in order to enhance wave transmission and hence to improve imaging performance. Numerical simulations demonstrated that for a point acoustic source an image as small as 0.16λ can be formed.