Radially Polarized Light for Detection and Nanolocalization of Dielectric Particles on a Planar Substrate

Abstract

A fast noninvasive method based on scattering from a focused radially polarized light to detect and localize subwavelength nanoparticles on a substrate is presented. The technique relies on polarization matching in the far field between scattered and spurious reflected fields. Results show a localization uncertainty of ≈10^{-4}λ^{2} is possible for a particle of area ≈λ^{2}/16. The effect of simple pupil shaping is also shown.