Figure 1.

Focal spot characterization for different angles of incidence source. (a) (left) Schematic illustration of focusing of on-axis and off-axis light by a metasurface doublet lens. (right) Simulated focal plane intensity for different incident angles. (Reproduced from [24] with permission.) (b) The Ray diagram obtained by adding the aperture meta-lens resulting in diffraction-limited focusing along the focal plane. (c) Focal spot measurement setup. (1–5) Focal spot intensity profile at (1) 0°, (2) 6°, (3) 12°, (4) 18°, (5) 25° incidence angle. (Reproduced from [25] with permission.)