Angular momentum conservation in counter-propagating vectorially structured light
Optics
2021-01-04 v1
Abstract
It is well-known that electric spin angular momentum and electric orbital angular momentum are conserved under paraxial propagation of travelling waves in free-space. Here we study the electric and magnetic angular momentum in counter-propagating waves and show both theoretically and experimentally that neither component alone is conserved except in special cases. We attribute this non-conservation to spin-spin and orbit-orbit coupling between the electric and magnetic fields. This work generalises previous findings based on travelling waves, explains the apparent spin-orbit coupling in counter-propagating paraxial light, and broadens our understanding of angular momentum conservation in arbitrary structured light waves.
Cite
@article{arxiv.2005.02739,
title = {Angular momentum conservation in counter-propagating vectorially structured light},
author = {Hang Li and Valeria Rodriguez-Fajardo and Peifeng Chen and Andrew Forbes},
journal= {arXiv preprint arXiv:2005.02739},
year = {2021}
}