High-efficiency wide-angle anomalous refraction with acoustic metagrating

The emergent metagrating, with its unique and flexible beam shaping capabilities, offers new paths to efficient modulation of acoustic waves. In this work, an acoustic metagrating is demonstrated for high-efficiency and wide-angle anomalous refraction. It is shown that the normal reflection and transmission can be totally suppressed by properly modulating the amplitude and phase characteristics of the metagrating supercells for high-efficiency anomalous refraction. The anomalous refraction behavior is achieved in the wide range of incident angles from 28° to 78°, and the efficiency of −1st order diffraction is higher than 90% by finely designing the metagrating structure. The anomalous refraction behaviors are verified experimentally at incidence angle of 28°, 45°, and 78°, respectively. The demonstrated metagrating is anticipated to possess efficient wide-angle composite wavefront engineering applications in such fields as communications.