Perfect absorption of water waves by linear or nonlinear critical coupling

E. Monsalve (1) , A. Maurel (2) , P. Petitjeans (1) , V. Pagneux (3)

1 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
2 IL - Institut Langevin - Ondes et Images (UMR7587)
3 LAUM - Laboratoire d'Acoustique de l'Université du Mans

We report on experiments of perfect absorption for surface gravity waves impinging a wall structured by a subwavelength resonator. By tuning the geometry of the resonator, a balance is achieved between the radiation damping and the intrinsic viscous damping, resulting in perfect absorption by critical coupling. Besides, it is shown that the resistance of the resonator, hence the intrinsic damping, can be controlled by the wave amplitude, which provides a way for perfect absorption tuned by nonlinear mechanisms. The perfect absorber that we propose, without moving parts or added material, is simple and robust and presents a deeply subwavelength ratio wavelength/thickness of ≃18.

Mots clés: Wave propagation; Absorption band; Profilometry; Cavity resonance; Surface waves; Wave energy resource

Domaines: Mécanique des fluides [physics.class-ph]

E. Monsalve, A. Maurel, P. Petitjeans, V. Pagneux. Perfect absorption of water waves by linear or nonlinear critical coupling. Applied Physics Letters, 2019, 114 (1), pp.013901. ⟨10.1063/1.5075541⟩. ⟨hal-02936815⟩