Topology optimization of high-efficiency on-chip single photon sources

Abstract

The realization of integrated quantum photonic circuits is crucial for scalable quantum computing and information processing applications. One of the milestones is the realization of highly-efficient coupling of pre-determined single-photon sources into the on-chip environment. Along with solid-state quantum sources, like quantum dots and defects in solids, quantum defects in 2D materials have attracted significant interest due to their quantum emission properties and stability. We have developed an adjoint-topology optimization framework to improve the coupling efficiency of color centers in hBN to the silicon nitride platform. We have demonstrated more than 75% coupling efficiency with a topology optimized coupler.