"Shape-Preserving Accelerating Underwater Acoustic Beams"

This talk will present the first observation of an underwater acoustic shape-preserving accelerating beam. Accelerating beams were first demonstrated in the context of optics less than a decade ago. Since then, the idea has branched into plasmonics, ultrasonics, and even for matter waves.  

The motivation for generating accelerating acoustic beams underwater and the experiments will be discussed. The beam exhibits transverse acceleration along a parabolic trajectory whilst preserving its cross-sectional shape for more than 6 Rayleigh lengths. The beam is generated in the Rafael Underwater Test Facility using a tailored phase mask and a single projector. Such beams have promising applications in the fields of SONAR, hydrography, medical ultrasound, and microparticle manipulation, and could provide new means to study non-linear interactions of acoustic beams.