Unidirectional efficient hybrid coupler for an integrated single-photon source

Hybrid integrated quantum photonic circuits possess the potential to scale up the number of quantum nodes with distributed quantum-information-processing units at affordable resources. One of the key requirements is to achieve high-efficiency and unidirectional coupling of single quantum emitters into the low loss dielectric photonic waveguide modes. Plasmonic waveguides have the capability to have high coupling efficiency due to enhanced light-matter interactions. However, they suffer from significant propagation losses. Here we design and numerically demonstrate an on-chip hybrid plasmonic-photonic integrated single-photon source that enhances the emission rate of a quantum emitter and possesses unidirectional emission to a waveguide with high coupling efficiency. Currently, the emission rate of the single emitter is enhanced by a factor of 20, and the coupling efficiency from the single emitter into the photonic circuit exceeds 70%. The integrated hybrid single-photon source could find applications in quantum-information technologies.(c) 2022 Optica Publishing Group