Single chip simultaneous chiral and achiral imaging based on high efficiency 3D plasmonic metalens

Abstract

We propose and experimentally demonstrate a single chip metasurface for simultaneous chiral and achiral imaging and polarimetric detecting using a high efficiency three dimensional plasmonic metalens (3D-PM) with capability of designed separation of different circular polarizations. The proposed 3D-PM combines both propagating and geometric phases so that two orthogonal circular polarization components of the incidence can be precisely separated and imaged into two channels and the incident polarization state can be detected with differentiation of the two channels. One single set of an array of Au layer covered anisotropic polymethyl methacrylate elliptical nanopillars is employed, in which height of each nanopillar is added as a new design degree of freedom to realize both full phase manipulation (0–2π) and high efficiency (>0.85) with coupled equivalent Fabry–Pérot cavity and localized surface plasmons. At design wavelength of 1550 nm, experimental results show that optical resolution of both chiral and achiral images approaches the diffraction limit, extinction ratio of circular polarizations in two channels is ∼33:1, and the energy efficiency reaches ∼63 %. The proposed 3D-PM provides a new and simple way for chiral/achiral imaging and polarimetric measurement, and can be applied in integrated optics, optical communication, and biomolecule detection.

Keywords

• chiral and achiral image
• differentiation
• polarimetric detection
• single chip plasmonic metalens