Self-collimation of Ultrasonic Waves in a Two-dimensional Prism-shaped Phononic Crystal

The self-collimation of ultrasonic waves in a two-dimensional prism-shaped phononic crystal (PC) with a square lattice immersed in water was theoretically and experimentally investigated. The acoustic pressure fields at the frequencies of the first and the second pass bands were calculated with and without the PC in the acoustic path by using the finite element method. The normalized pressure distributions of the ultrasonic waves transmitted through water only and through the PC were theoretically and experimentally obtained along the direction perpendicular to the beam axis. We demonstrated self-collimation and directivity enhancement of the ultrasonic waves in the two-dimensional prism-shaped PC.