Acoustical imaging with negative refraction

Abstract

It is well known that the resolution limit of acoustical images is limited by diffraction to λ/2 where λ is the sound wavelength. Negative refraction proposed by Veselago in 1968 shows possibility of defeating the diffraction limit. His work is for electromagnetic waves. Recently it has been shown experimentally that negative refraction can be achieved for both electromagnetic waves and sound waves by using photonic crystals ad phononic crystals respectively. John Pendry proposed the concept of 'perfect lens' using negative refraction for electromagnetic waves. In this paper, we propose a 'perfect lens' for sound waves and an acoustical imaging system incorporating the 'perfect lens' is also outlined.