Embedded InP-on-Si 1D photonic crystal emitting in the topological mode

Abstract

Great potential for improvements in engineering photonic applications is seen in topological photonic systems due to facilitated single mode operation and since the inherent topological protection might make them more robust to imperfections in design and fabrication [1]. There have been recent demonstrations of lasing in suspended 1D nanobeam structures based on a topological cavity, where the suspension leads to a high-Q cavity enabling efficient lasing [2]. In an actual integrated system, however, structures would ideally be embedded in oxide, which will inevitably reduce the refractive index contrast (n>1) and therefore lead to a lower Q.