Implementation of the SSH model in an optical ring resonator

The implementation of physical models with topological features in optical systems has garnered much attention in recent times. In particular, on-chip integrated photonics platforms are promising platforms enabling us to take advantage of the promise of topologically robust modes against inevitable fabrication defects. Here, we propose to study the SSH model superimposed in an optical ring resonator in a quantitative way using electromagnetic simulations. We are interested in lhe localized states that appear when a topological phase transition is introduced into the ring. In particular, we examine the extent to which topologically protected modes maintain their properties in the presence of random deformations in the surrounding lattice. We find that the modes maintain their properties when small amounts of disorder are introduced into the system. We also study loss mechanisms in the localized states, distinguishing between losses to the adjacent waveguide and to radiation, finding that the topological protection only applies to the former.