Negatively refracted transverse waves : study of the ultrasonic field at the exit of an elastic phononic crystal

A two-dimensional phononic crystal (PC) with square lattices composed of air holes in aluminum matrix is studied. The band structure of the PC exhibits some properties which allow the negative refraction of transverse wave transmitted through the PC. The left-handed behaviour of the PC is verified numerically with an emphasis on the process of refracted beam construction near the exit surface of the PC.