3D Zeros in Electromagnetic Fields

TL;DR

This paper investigates three-dimensional electromagnetic field zeros, classifying their features and exploring their potential for advanced optical applications like nanoscale manipulation and super-resolution imaging.

Contribution

It introduces a new framework for classifying 3D electromagnetic zeros and analyzes their unique properties in non-paraxial fields, expanding understanding beyond traditional 2D dark spots.

Findings

3D electromagnetic zeros can exist as fully localized points in non-paraxial fields.

These zeros influence energy, momentum, and polarization textures in distinctive ways.

The study proposes potential applications in nanoscale manipulation and super-resolution imaging.

Abstract

We present a study of 3D electromagnetic field zeros, uncovering their remarkable characteristic features and propose a classifying framework. These are a special case of general dark spots in optical fields, which sculpt light's spatial structure into matter-moving, information-rich vortices, escape the diffraction limit for single-molecule imaging, and can trap particles for nanoscale manipulation. Conventional dark spots are two-dimensional in two aspects: localised in a plane and having a non-zero out-of-plane field component. We focus on non-paraxial fields, where three-dimensional dark spots can exist non-stably at fully localised points, making distinct imprints in the flux of energy and momentum, and in the light's polarisation texture. With this work, we hope to enhance current dark spot applications, or inspire new ones impossible with lower-dimensional zeros.