Figure 3
Library of different silicon nanopillars working at 1310 nm providing the recipe to build up a dual-functional metalens. (a) Phase delays for TE (y-delay) and TM (x-delay) polarizations, (b) Transmittance of each nanopillar under TE (Ty) and TM (Tx) polarization compared with the average transmittance (Tavg) calculated among all the transmittance values. (c) Different types of pillars composing the meta-library. Rectangular and elliptical pillars (A–B) are the more common, with respect to the other two types (C–D) made of two paired pillars, with a rectangular base inscribed within a concentric circumference of radius 250 nm and placed at a distance of 300 nm between the two centers. (d) Complete list of the metaatoms library showing the type of pillars and the corresponding size.
