Single-shot quantitative amplitude and phase imaging based on a pair of all-dielectric metasurfaces

Abstract

Quantitative amplitude and phase imaging (QAPI) has been an effective technique to examine label-free biomedical samples. Simple and reliable QAPI techniques realized by replacing conventional bulky optical elements with planar structures will improve the system portability and facilitate in vivo imaging applications. Here, we propose a single-shot QAPI method realized by simply inserting a pair of all-dielectric geometric phase metasurfaces into a traditional microscope. The first metasurface splits a linearly polarized incident beam into two circularly polarized components and the following metasurface deflects the two beams back toward their initial directions. The metasurface pair generates two laterally displaced replicas of the input object, of which the interference forms a retardance image with a bias retardation controlled by an analyzer. The amplitude and phase information of the object is reconstructed from four retardance images simultaneously recorded by a polarized camera. The metasurface pair can be placed near any conjugate plane of the object, which provides a flexible and robust configuration for QAPI, demonstrating its wide usage in live imaging.