Weak measurement of elliptical dipole moments by C point splitting

TL;DR

This paper introduces a weak measurement technique using far-field polarization to determine the elliptical dipole moments of particles by analyzing C point splitting in their emission patterns.

Contribution

It presents a novel optical weak measurement method that links far-field polarization features to the dipole moments of particles, enabling precise characterization.

Findings

Successfully determined elliptical dipole moments via C point analysis

Demonstrated the method on particles at interfaces

Revealed small angular separations for high eccentricity dipoles

Abstract

We investigate points of circular polarization in the far field of elliptically polarized dipoles and establish a relation between the angular position and helicity of these C points and the dipole moment. In the case of highly eccentric dipoles, the C points of opposite handedness exhibit only a small angular separation and occur in the low intensity region of the emission pattern. In this regard, we introduce an optical weak measurement approach that utilizes the transverse electric (azimuthal) and transverse magnetic (radial) far-field polarization basis. Projecting the far field onto a spatially varying post-selected polarization state reveals the angular separation and the helicity of the C points. We demonstrate the applicability of this approach and determine the elliptical dipole moment of a particle sitting on an interface by measuring the C points in its far field.