Fig. 3: Control nanoholes over packing density, shape, orientation, and distribution.
From: 25 nm-Feature, 104-aspect-ratio, 10 mm2-area single-pulsed laser nanolithography
a Deep nanohole arrays of 3 × 3 with 500 nm spacing in YAG. b Histogram of duty cycles at different limit spacing in (a). Inset, pink spheres denote nanholes, where D stands for the diameter of a nanohole, and P illustrates the period between adjacent nanoholes. c Orientation control of nanoholes. Schematic illustration (left) and SEM images of elliptical nanoholes with orientations of 0o, 45o, 90o, and 135o (right). Double arrows indicate the orientation of nanoholes. d Optical microscope images of the nanohole patterns designed as Archimedean-spiral-like structure with nanoholes of 240 nm (left), 260 nm (middle), and 280 nm (right) in diameter, respectively. Insets, local SEM images. e Phase retardance distribution images of the nanohole structures corresponding to (d). Scale bars, 500 nm [a, c], 10 µm [d, e], and 1000 nm [insets in d].
