Topological Photonics

First discovered for electrons in condensed matter system, the field of topological insulator has recently enlarged to photonic system with optical materials. Photonic metasurfaces offer a versatile and powerful platform to explore topological properties on demand thanks to their symmetry engineering, thus providing means of testing solid state theoretical models using photonic analogues. Moreover, combined with gain and loss of optical materials, topological photonic opens the way to non hermitian physics in which exotic effects of parity time symmetry are expected. Topological concepts applied to photonics promises also devices robust to environmental changes and technological imperfections, leading to communication without backscattering and robust single mode lasing.

Approaches

Non-hermitien topology in dielectric or metallic metasurface

experimental demonstration of the on demand engineering of the band diagram of photonic metasurface from flatband to Dirac cones – two key band dispersions of topological physics.

Topological effects of photonic graphene objects

observation of edge-states in photonic tube and topological transition in twisted bilayer of photonic crystal of honeycomb lattice. Working in optical wavelengths provides the possibility to observe topological effects that were only predicted, but not demonstrated due to experimental difficulties of manipulating nano-objects of solid state physics such as single carbon nanotube

Projet

Pholding, ToRe (IDEX Breakthrough)

Involved persons :

• Permanent staff : Lydie Ferrier (coord.), Hai-Son Nguyen, Ségolène Callard, Alexandre Danescu, Jean-Louis Leclerq
• Non permanent staff : Rémi Briche (PhD), Paul Bouteyre (Post-doc)

(a). Metallic metasurface with a localized state. (b) Photonic tube and twisted-bilayers of photonic graphene. (c) Experimental demonstration of band inversion and emergence of exceptional points in all-dielectric metasurface.