Double-Helix Singularity and Vortex-Antivortex Annihilation in Space-Time Helical Pulses

TL;DR

This paper introduces a new class of ultrafast helical light pulses with double-helix topological singularities that maintain their structure during propagation and exhibit vortex-antivortex dynamics, offering potential for advanced information encoding.

Contribution

The study presents the theoretical discovery of helical pulses with double-helix singularities, extending Maxwell's equations to include chiral, angular momentum-dependent structures.

Findings

Double-helix singularities are topologically invariant during propagation.

Ultrafast space-time pulses exhibit vortex-antivortex generation and annihilation.

Potential application in information encoding with structured light.

Abstract

Topological structures reveal the hidden secrets and beauty in nature, such as the double helix in DNA, whilst, the manipula-tion of which in physical fields, especially in ultrafast struc-tured light, draw booming attention. Here we introduce a new family of spatiotemporal light fields, i.e. helical pulses, carry-ing sophisticated double-helix singularities in its electromag-netic topological structures. The helical pulses were solved from Maxwell's equation as chiral extensions of toroidal light pulses but with controlled angular momentum dependence. We unveil that the double helix singularities can maintain their topological invariance during propagation and the field exhibits paired generation and annihilation of vortices and antivortices in ultrafast space-time, so as to be potential information carriers beating previous conventional vortex structured light.