One-way acoustic beam splitting in spatial four-waveguide couplers designed by adiabatic passage

Abstract

In this work, we introduce quantum-mechanical adiabatic passage (AP) into the design of spatial acoustic four-waveguide (WG) couplers. Thanks to the agreement in form between the Schrödinger equation in quantum mechanics and the coupled-mode equation of classical wave, the behavior of propagating wave in coupled WGs is capable of mapping to quantum states driven by external fields. By coupling the input and output WGs with a mediator WG in space, an apparent beam splitting is realized and the ratio of intensity can be customized arbitrarily by altering the space-dependent coupling strengths. Moreover, a one-way propagation feature is exhibited in the spatial coupler when an appropriate loss is introduced in the mediator WG owing to the existence of dark state. This work builds a bridge between quantum adiabatic technology and acoustic beam splitter, which may have potential applications in acoustic communication, filtering and detection.

Switchable acoustic projection displays based on coding composite structures

“…In past several years, acoustic metasurface (a composite structure with planer configuration) has been demonstrated to be good candidates to achieve various fascinating phenomena, such as beam deflection [11][12][13], beam focusing [14][15][16][17][18][19], vortex beam [20], splitting beam [21] and Airy beam [22] by utilizing Helmholtz resonators [23,24], coiling-up cavities [25], or spiral particles [26]. Owing to the shifts of equivalent refractive index induced by resonance effect, arbitrary phase or amplitude response can be obtained by adopting ultrathin structural design, making it is suitable to be integrated in acoustic devices.…”