Reply to "Comment on 'Theory for tailoring sonic devices: Diffraction dominates over refraction' "

TL;DR

This paper defends the idea that diffraction effects are significant in acoustic lenses at several wavelengths, using FDTD simulations to show that diffraction and refraction are interconnected even at small scales.

Contribution

It provides a detailed FDTD simulation analysis demonstrating the interplay of diffraction and refraction in acoustic lenses, challenging previous assumptions about their scale dependence.

Findings

FDTD simulations show diffraction and refraction are intertwined.

Significant differences found between simulations and previous experiments.

Diffraction effects are relevant even at small lens scales.

Abstract

In their comment, A. Hakansson, J. Sanchez-Dehesa, F. Cervera, F. Meseguer, L. Sanchis, and J. Llinares say that our conclusion stating that diffraction prevails over refraction in acoustic lenses whose aperture is of several wavelengths, such as those addressed in our calculations [N. Garcia, M. Nieto-Vesperinas, E. V. Ponizovskaya, and M.Torres, Phys. Rev. E 67, 046606 (2003)] and in their experiments [F.Cervera, L. Sanchis, J. V. Sanchez-Perez, R. Martinez-Sala, C. Rubio, F.Meseguer, C. Lopez, D. Caballero, and J. Sanchez-Dehesa, Phys. Rev. Lett.88, 023902 (2003)], is misleading because the size of their lenses is larger than ours. They state that diffraction effects are negligible at the scale of their experiments. In this reply we calculate the propagation of a plane wave through both a lens and a slab of aluminum cylinders, identical to those presented by such authors in previous experiments, by using a finite difference time domain (FDTD) method. We then compare our results to the experiments previously reported by the authors of the comment and significant differences are found. Our present calculations show that refraction and diffraction are intrinsically interwoven also at the scale of their experiments.