3D zeros in electromagnetic fields

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 2D in two aspects: localized in a plane and having a non-zero out-of-plane field component. We focus on non-paraxial fields, where 3D dark spots can exist non-stably at fully localized points, making distinct imprints in the flux of energy and momentum, and in the light’s polarization texture. With this work, we hope to enhance current dark spot applications, or inspire new ones impossible with lower-dimensional zeros.