Resonant transmission and mode modulation of acoustic waves in H-shaped metallic gratings

Yu-Qiang Deng,Dong-Xiang Qi,Ru-Wen Peng,Ren-Hao Fan,Kun Zhang

doi:10.1063/1.4919675

Abstract

In this work, we demonstrate that resonant full transmission of acoustic waves exists in subwavelength H-shaped metallic gratings, and transmission peaks can be efficiently tuned by adjusting the grating geometry. We investigate this phenomenon through both numerical simulations and theoretical calculations based on rigorous-coupled wave analysis. The transmission peaks are originated from Fabry-Perot resonances together with the couplings between the diffractive wave on the surface and the multiple guided modes in the slits. Moreover, the transmission modes can be efficiently tuned by adjusting the cavity geometry, without changing the grating thickness. The mechanism is analyzed based on an equivalent circuit model and verified by both the theoretical calculations and the numerical simulations. This research has potential application in acoustic-device miniaturization over a wide range of wavelengths.

Highlights

Enhancement of sound transmission is a classic problem that people devote to solve, especially when material is at subwavelength scale
We demonstrate that resonant full transmission of acoustic waves exists in subwavelength H-shaped metallic gratings, and transmission peaks can be efficiently tuned by adjusting the grating geometry
We find that full resonant transmission of acoustic waves exists in this H-shaped metallic grating, and the transmission peak can be tuned through adjustment of the geometrical parameters of the inside cavity, without changing the grating thickness

Summary

INTRODUCTION

Enhancement of sound transmission is a classic problem that people devote to solve, especially when material is at subwavelength scale. In H-shaped structure.[34] In this work, we find that full resonant transmission of acoustic waves exists in this H-shaped metallic grating, and the transmission peak can be tuned through adjustment of the geometrical parameters of the inside cavity, without changing the grating thickness. This structure may have potential applications in acoustic-device miniaturization over a wide range of wavelengths, including acoustic filters and tunable sonic imaging.

GEOMETRICAL STRUCTURE AND NUMERICAL RESULTS

THEORETICAL MODEL AND ANALYSIS

RESONANT MODE TUNING

CONCLUSIONS