Numerical simulation of acoustic lenses based on Fresnel zone plate

In this work, we propose formulas for constructing Fresnel zone plates (FZP) used to focus acoustic waves generated from plane and spherical waves. The proposed formulas for FZP are frequency dependent. We also develop a MATLAB program for performing numerical simulation of acoustic wave propagation through FZP in two dimensions to validate the proposed formulas. Numerical results in both cases indicate that the FZP can successfully focus acoustic waves at the frequency of 1 kHz and the wave speed of 330 m/s. In the future we will construct a real FZP and perform a laboratory measurement to validate the proposed formulas and simulation results.