Acoustic waveguide based on cascaded Luneburg lens

This paper investigates the acoustic Luneburg Lens (ALL) as a design framework for guiding acoustic wave propagation. In this study, an acoustic waveguide is proposed based on the characteristics of both acoustic wave focusing and collimation of cascaded ALLs. The continuous variation of the refractive index of the ALL is achieved by using lattice unit cells with a graded filling ratio. A cascaded ALL waveguide device is fabricated based on the additive manufacturing technique. The experimental results obtained with this device are consistent with the numerical simulations and theoretical calculations.