Experimental Realization of Multiple Topological Edge States in a One-Dimensional Photonic Lattice

TL;DR

This paper demonstrates a silicon photonic lattice that can support multiple topological edge states, enabling robust light transport and dynamic phase transitions, which broadens the potential for topological photonic devices.

Contribution

It introduces a flexible topological photonic lattice capable of realizing multiple nontrivial phases and edge states on a silicon platform, surpassing previous limited quasi-one-dimensional models.

Findings

Multiple topological dispersion bands realized

Edge states observed with femtosecond dynamics

Transitions between different topological phases demonstrated

Abstract

Topological photonic systems offer light transport that is robust against defects and disorder, promising a new generation of chip-scale photonic devices and facilitating energy-efficient on-chip information routing and processing. However, present quasi one-dimensional designs, such as the Su-Schrieffer-Heeger (SSH) and Rice-Mele (RM) models, support only a limited number of nontrivial phases due to restrictions on dispersion band engineering. Here, we experimentally demonstrate a flexible topological photonic lattice on a silicon photonic platform that realizes multiple topologically nontrivial dispersion bands. By suitably setting the couplings between the one-dimensional waveguides, different lattices can exhibit the transition between multiple different topological phases and allow the independent realization of the corresponding edge states. Heterodyne measurements clearly reveal the ultrafast transport dynamics of the edge states in different phases at a femto-second scale, validating the designed topological features. Our study equips topological models with enriched edge dynamics and considerably expands the scope to engineer unique topological features into photonic, acoustic and atomic systems.