Tunable Acoustic Nonreciprocity in Strongly Nonlinear Waveguides with Asymmetry

Abstract

While there has been exciting progress in the emerging area of nonlinear acoustic nonreciprocity, one of the main challenges is to realize $p\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}v\phantom{\rule{0}{0ex}}e$ nonreciprocal acoustic waveguides with predictable, reliable broadband operation. Here the authors demonstrate an entirely passive nonreciprocal acoustic waveguide that enables transmission of acoustic waves in a preferred direction. Moreover, due to its strong nonlinearity, this nonreciprocity is passively adaptive to energy and can be predictively tuned by the intensity of the applied broadband excitation. Related applications span telecommunication, optics, and biomedical imaging.