Chirality in photonic systems

TL;DR

This paper reviews how chirality and spin-orbit coupling in photonic systems lead to various phenomena like spin Hall effects, topological insulators, and Berry curvature, highlighting the design flexibility and potential for novel optical effects.

Contribution

It provides a comprehensive qualitative review of recent developments in chiral photonic systems, including topological and spin-dependent phenomena.

Findings

Demonstration of optical spin Hall effect

Creation of spin currents with topological protection

Observation of Berry curvature effects in photonics

Abstract

The optical modes of photonic structures are the so-called TE and TM modes which bring intrinsic spin-orbit coupling and chirality to these systems. This, combined with the unique flexibility of design of the photonic potential, and the possibility to mix photon states with excitonic resonances, sensitive to magnetic field and interactions, allows to achieve many phenomena, often analogous to other solid state systems. In this contribution, we review in a qualitative and comprehensive way several of these realizations, namely the optical spin Hall effect, the creation of spin currents protected by a non-trivial geometry, Berry curvature for photons, and the photonic/polaritonic topological insulator.