Bidirectional asymmetric acoustic focusing with two flat acoustic metasurfaces Project supported by the National Natural Science Foundation of China (Grant Nos. 11704193, 11674175, and 11704192), the “333” Project of Jiangsu Province, China (Grant No. BRA2017451), and the Postgraduate Research & Practice Innovation Program of Jiangsu Province, China (Grant No. KYCX18_1185). |
(color online) (a) Spatial phase profile in y axis for two parabolic trajectories [y = 0.5x2 (y ≤ 0) and y = −0.5x2 (y ≥ 0)] (PT-1) and (b) acoustic field distribution of the PT-1 through the AM-1. Scattered dots in panel (a) represent discrete phases of 80 subunits (one dot corresponds to one subunit). |