Underwater acoustic positioning based on valley-chirality locked beam of sonic system

Abstract Underwater acoustic positioning is the most important and reliable technology for the positioning and tracking of objectives in deep seas. However, realizing a directional and robust acoustic propagation which immunizes against surrounding noise, interference signals and various defects is still a challenge. Topological physics in acoustics, which has significantly revolutionized our scientific cognition of classical wave characteristics, provides an excellent platform for the control of the directional and robust acoustic beams. In this paper, we design a waterborne sonic system consisted of triangular prisms which are periodically distributed in a triangular lattice and systematically investigate the robust edge propagation which is induced by the analogy of the valley Hall polarization. The valley-chirality locked acoustic beam propagates along a −68.38o (or 8.38°) refraction angle and expresses as a directional needle-like pattern with a 15.58o (or 17.72°) width. It can be used to detect the far-field deep sea. Furthermore, the sonic system can only receive the sound signal from the −68.38o (or 8.38°) direction, while the background noises and the interference signals from other directions are well suppressed. This sonic system with the excellent immunization against various defects, the needle-like acoustic beams and the directional receptions will greatly improve the performance and functionalities of underwater acoustic devices from the detection, positive position, active position, and navigation.