Fig. 2
From: Arbitrarily structured quantum emission with a multifunctional metalens
Design and characterisation of a polarisation beam-splitting metalens. A Schematic of the meta-atoms made of low-loss a-Si:H on silica. B Calculated phase delay and transmission library of meta-atoms covering 2π for both LPx and LPy light. The average transmission is 94%. C Implemented phase maps for the metalens and gradient functions for LPx and LPy incidence. D Images of the fabricated metalens taken with an (i) optical microscope and (ii) scanning electron microscope. E Polar plot of the measured far-field deflection of the metalens under LPx and LPy dipole-like illumination. The bottom images are associated back-focal-plane image patterns. F Calculated collection efficiency of an isotropic emitter in free space as a function of numerical aperture of the collecting lens. A cyan star marks our metalens collection efficiency with NA = 0.869. Inset: point spread function of the metalens under the LPx and LPy plane-wave incidence, where the scatter and solid lines represent the experimental and theoretical characterisations, respectively