Abstract

So far topologically-protected waveguiding in photonics has been largely based on two-dimensional (2D) topological phases described by Chern or spin Chern numbers, where disorder-robust transport along one-dimensional (1D) edges is protected by the topology of the bulk modes [1]. This has the disadvantage of requiring either larger device sizes compared to conventional 1D waveguides or the use of synthetic dimensions [2]. Recently it was shown that spin-momentum locked (helical) transport protected against certain classes of disorder also emerges in static 1D electronic systems by combining a magnetic field with strong spin-orbit coupling [3]; instead of using localized edge states, bulk modes are directly optimized to eliminate backscattering. We show how to implement photonic 1D helical dispersion, enabling waveguides combining compactness with resistance to disorder.

© 2019 IEEE