101823.fig.002a
(a)
101823.fig.002b
(b)
Figure 2: Schematics of the proposed light-collecting device: (a) overall layout: 9 (3 × 3) blocks of optical elements: 4 blocks of 1D lamellar grating structures, 4 blocks of 2D lamellar grating structures, and a single block of nonpatterned element at the center and (b) cross-sectional view: depth of lens and focal length.