Finite-energy unidirectional Hopfion-like spacetime localized electromagnetic fields in vacuum.

作者：Ioannis M. Besieris, Peeter Saari · 发表于：Optics Express · 年份：2025 · DOI：10.1364/oe.566938 · 研究领域：Medicine

Based on two Bateman conjugate functions, a class of finite-energy spatiotemporally localized null electromagnetic fields in vacuum have been constructed. These wavepackets share with the basic Hopfion, as well as higher-order Hopf-Ranada solutions, topological properties dealing with linked and knotted electromagnetic field lines. Contrary to the Hopf-Ranada solutions, however, they are unidirectional and devoid of energy backflow, the latter being a counterintuitive phenomenon whereby, even for forward-propagating plane wave components, the energy locally propagates backward. Conservation laws for electromagnetic chirality and helicity for these novel wavepackets have been studied.