Retrieving the Size of Deep-subwavelength Objects via Tunable Optical Spin-Orbit Coupling

TL;DR

This paper introduces a novel far-field super-resolution imaging method that uses tunable optical spin-orbit coupling and local polarization analysis to accurately determine the size of nano-particles much smaller than the wavelength.

Contribution

It presents a new approach combining plane wave illumination and a dipole model to retrieve nano-particle sizes with high sensitivity, surpassing traditional resolution limits.

Findings

Achieved subwavelength size retrieval of nanoparticles.

Demonstrated sensitivity through a dipole tunneling model.

Enabled far-field super-resolution imaging of nanoparticles.

Abstract

We propose a scheme to retrieve the size parameters of a nano-particle on a glass substrate at a scale much smaller than the wavelength. This is achieved by illuminating the particle using two plane waves to create rich and non-trivial local polarization distributions, and observing the far-field scattering pattern into the substrate. A simple dipole model which exploits tunneling effect of evanescent field into regions beyond the critical angle, as well as directional scattering due to spin-orbit coupling is developed, to relate the particle's shape, size and position to the far-field scattering with remarkable sensitivity. Our method brings about a far-field super-resolution imaging scheme based on the interaction of vectorial light with nanoparticles.