Sonic crystals and sonic wave-guides

Abstract

A sonic crystal is a finite-size periodic array composed of scatterers embedded in a homogeneous material. It should have full band-gaps where any sound wave is not allowed to propagate but is reflected completely. It is actually a sonic version of a photonic crystal. Since similarities and differences between the photonic and electronic band structures were discussed and summarized in 1993 by Yablonovitch, photonic crystals have been intensively investigated from the physical and application-oriented points of view. In the same time frame, sonic and phononic crystals have been discussed to realize acoustic band-gaps, wave-guides and filters. Their first experimental realizations of full band-gaps were both reported in 1998. Two-dimensional sonic crystals of rigid cylinders in air have been recently revealed to be promising for acoustical coupled wave-guides constructed in a sonic-crystal slab. This review focuses on sonic crystals corresponding to photonic crystals, and reviews papers on the fundamental physical aspects, methods of theoretical analyses, experimental techniques to realize two-dimensional sonic crystals, wave-guides and coupled wave-guides, and finally ideas of sonic circuits built in sonic-crystal slabs.