Supertoroidal light pulses: Propagating electromagnetic skyrmions in free space

Abstract

Topologically complex transient electromagnetic fields give access to nontrivial light-matter interactions and provide additional degrees of freedom for information transfer. An important example of such electromagnetic excitations are space-time non-separable single-cycle pulses of toroidal topology, the exact solutions of Maxwell described by Hellwarth and Nouchi in 1996 and recently observed experimentally. Here we introduce a new family of electromagnetic excitation, the supertoroidal electromagnetic pulses, in which the Hellwarth-Nouchi pulse is just the simplest member. The supertoroidal pulses exhibit skyrmionic structure of the electromagnetic fields, multiple singularities in the Poynting vector maps and fractal-like distributions of energy backflow. They are of interest for transient light-matter interactions, ultrafast optics, spectroscopy, and toroidal electrodynamics.

Dispersion Characteristic of Spatiotemporal Sharply Autofocused Vector Airy-Circular Airy Gaussian Vortex Wave Packets

“…Spatiotemporal wave packet theory [1] and ultrashort laser pulses [2][3][4][5][6][7] have received considerable attention by the researchers in the field of laser technology for the past decades. Hellwarth et al have studied the focused one-cycle electromagnetic pulses to introduce focused vector wave packets [8].…”