FIG. 3: The displacement field patterns under the illumination of a 2D point source. The center of the first layer of holes is located at x = a . The results for the 9-layer structure are shown in (a)-(c). The source is located at x = (a) 0, (b) − 2 . 5 a , and (c) − 5 a , respectively. Similar simulation results for the 13-layer structure are shown in (d)-(f). 12