Energy-distributable waterborne acoustic launcher for directional sensing

Abstract

Highly directional launch and intensity adjustment of underwater acoustic signals are crucial in many areas such as abyssal navigation, underwater signal communication, and detection for marine biology. Inspired by the phenomenon that aquatic animals like dolphins detect and track prey with high resolution, we propose an energy-distributable directional sensing strategy which can achieve parallel needle-like transmitting sound beams with adjustable energy based on out-coupling valley-polarized edge states. The acoustic spin angular momentum and energy flow distribution at different interfaces inside the phononic crystal are provided and they show tight coupling. Furthermore, a sound beam with a width of 20° and an acoustic intensity enhancement factor ≈ 6.6 are observed in the far field. As an application, we show that this device can be used as an acoustic energy distributor. This communication pattern with excellent functionalities and performance provides a desirable idea for high-energy-level directional collimated underwater sensing and underwater acoustic energy distribution.