Observation of Local Symmetry in a Photonic System

Abstract

The concept of local symmetry has been shown to be a powerful tool in predicting and designing complex transport phenomena in stationary scattering off aperiodic media, in terms of symmetry‐adapted nonlocal currents. For time‐evolving wavepackets, the spatiotemporal correlations caused by local symmetries are more challenging to reveal. A recent formalism‐based nonlocal continuity equation shows how local symmetries are encoded into the dynamics of light propagation in discrete waveguide arrays governed by a Schrödinger equation. However, the experimental demonstration is elusive so far. Representative examples of locally symmetric, globally symmetric, and fully nonsymmetric configurations are fabricated in fs laser‐written photonic arrays and their dynamics are probed. The approach allows to distinguish all three types of structures.