High-frequency simulation of acoustic lenses based on Fresnel zone plate

In this work, we develop a Fortran program to simulate the propagation of high-frequency plane acoustic wave through Fresnel zone plate (FZP) in two dimensions. The simulation was carried out at the frequency of 200 kHz with the wave speed of 1,500 m/s. The thickness of FZP was also varied to determine its effect on the focusing of FZP. Numerical results show that FZP could successfully focus the acoustic wave. The results also matched well with the simulation result of a previously published work of underwater acoustics. An efficiency comparison between FZP and a scattering-type acoustic lens focusing a wave at the frequency of 2140 Hz and wave speed of 330 m/s was also reported.