Multi-functional resonant acoustic wave router

Routing wave at subwavelength scale remains an important scientific and technological challenge highly related to a variety of applications as information processing, energy harvesting and communication devices. We construct a compact multi-functional four-port system using as building blocks three-port acoustic devices. These latter act as splitter and combiner operating at the same frequency in the subwavelength regime. We start by experimentally demonstrating the splitter/combiner function of the three-port acoustic device composed of waveguides side loaded by Helmholtz resonators. Then, we optimize this device to achieve in addition perfect transmission. Finally, we propose a four-port system interconnecting the optimized three-port devices and we show various wave routing features with almost perfect transmission depending on the phase of the inputs.