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Essay: Photonic Crystals as a Platform to Explore New Physics

Che Ting Chan

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Phys. Rev. Lett. 135, 080001 – Published 19 August, 2025

DOI: https://doi.org/10.1103/kglg-yzcm

Abstract

Photonic crystals are artificial materials characterized by a photonic band structure that governs the propagation of light waves. The photonic gap was originally introduced to inhibit spontaneous emission and facilitate photon localization. In this essay, I will highlight how, despite the established understanding of photonic crystals, they remain highly relevant today. Their design flexibility, the duality symmetry inherent in Maxwell’s equations, and their functionality across a wide frequency range all allow the exploration of new areas in physics, each revealing unique phenomena. Examples include band topology and topological effects in structured light fields, as well as geometric concepts such as quantum geometry and the properties of non-Euclidean spaces. Furthermore, photonic crystals provide a valuable platform for studying non-Hermitian physics, including exceptional points and the non-Hermitian skin effect. Beyond their fundamental significance, these properties hold promise for advancing photonic technologies.

Part of a series of essays in Physical Review Letters which concisely present author visions for the future of their field.

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PRL Forward-Looking Essays

To welcome work from areas across the physical sciences and inspire the new generation of physicists, this series of forward-looking Essays is designed to envision future directions for a given topic .

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Phys. Rev. Lett. 135, 080001– Published 19 August, 2025
  • Received 29 April 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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