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ARTICLE

Reverse Energy Flows in Two-Dimensional Photonic Crystals and Similarities with Vortex Formation and Analogous Flows in Hydrodynamics

Andrey Pryamikov^*

Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia

* Corresponding Author: Andrey Pryamikov. Email:

(This article belongs to the Special Issue: Vortex Phenomena in Various Fields of Physics: from Hydrodynamics to Biophysics)

Fluid Dynamics & Materials Processing 2026, 22(3), 3 https://doi.org/10.32604/fdmp.2026.071903

Received 15 August 2025; Accepted 06 March 2026; Issue published 31 March 2026

Abstract

This paper examines the connection between photonic band-gap formation in two types of two-dimensional photonic crystals and the emergence of reverse electromagnetic energy flows generated by linearly polarized plane waves incident on a photonic-crystal slab. We show that these reverse energy flows, observed in both transmitted and reflected fields, originate from vortex structures in the Poynting vector. The resulting energy-flow patterns exhibit striking analogies to vortex formation in fluid motion past obstacles. The geometry and dynamics of the Poynting-vector vortices determine whether the incident electromagnetic energy is impeded, leading to the formation of photonic band gaps, or instead guided through the structure, enabling transmission.

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