Ultrathin Resistive Sheets for Broadband Coherent Absorption and Symmetrization of Acoustic Waves

The manipulation of acoustic waves is experimentally and theoretically investigated based on the concept coherent perfect absorption. It shown that absolute control antisymmetric modes an duct possible using ultrathin wire mesh. By varying relative phase two counterpropagating (normal or oblique) incident waves, absorption due to mesh can be tuned from zero unity. Experimental as well numerical results demonstrate this phenomenon extremely broadband---allowing, for instance, symmetrization wave with a short pulse in time domain.