Realization of Subwavelength Asymmetric Acoustic Transmission Based on Low-Frequency Forbidden Transmission

Abstract

One-way propagation of acoustic waves has been achieved using acoustic superlattices or nonlinear acoustic diodes, but these structures are much larger than the acoustic wavelength. This makes them impractical for applications such as low-frequency underwater signal transmission. The authors show that unidirectional acoustic wave propagation is possible with a device much smaller than the wavelength. Their design offers high rectification and broadband performance, and does not require an external power source.