Observation of Chiral Topological Transfer in a Non-Hermitian Photonic Lattice.

Abstract

Topological photonic states have garnered a wide range of research interest in photonics due to their robustness against disorders and imperfections. Here, we present a novel topological chiral transfer effect by combining topological pumping and dynamical mode braiding in non-Hermitian photonic lattices. Unlike conventional topological pumping, the transfer of topological edge states (TESs) exhibits dual asymmetry in both the input edge and propagation direction selections. Furthermore, the large energy gap between TESs and bulk states allows relaxation of adiabatic constraints, leading to a two-order-of-magnitude reduction in device length compared to previous designs, as demonstrated by experiments. Our findings not only advance the understanding of multi-degree-of-freedom non-Hermitian dynamics but also offer an accessible approach for developing high-density integrated photonic devices.