Customizable beam splitting in planar adiabatic acoustic couplers composed of cylindrical scatterers

In this work, five-waveguide (five-WG) acoustic couplers with planar configurations are designed based on quantumlike adiabatic transfer, through which the incident waves can efficiently transfer from the middle WG to the other two WGs with a customized intensity ratio. The five WGs are connected by space-varying cylindrical scatterers, and the coupling between two adjacent WGs is determined by two Gaussian pulses with a certain delay. Since the evolution process of acoustic waves can adiabatically follow the dark state, the coupler could have a broadband and stable performance. Moreover, it is easy to change the ratio of the beam splitting by utilizing different peak values of the coupling between the middle three WGs. The agreements between analytical, numerical, and experimental results confirm the feasibility of the design, providing an effective solution for high-performance acoustic beam splitters with customizable output intensities.