OAM-inspired new optics: the angular metalens

摘要

a A radial-quadratic phase focuses different linear phase gradients onto distinct axial positions. b An azimuthal-quadratic phase performs an analogous operation on orbital angular momentum (OAM) beams, mapping different azimuthal phase gradients onto distinct angular positions. c Its implementation in a metasurface form enables the combined measurement of polarization (spin σ) and OAM