A Waveguide-Coupled On-Chip Single-Photon Source

We investigate single-photon generation from individual self-assembled InGaAs quantum dots coupled to the guided optical mode of a GaAs photonic crystal waveguide. By performing confocal microscopy measurements on single dots positioned within the waveguide, we locate their positions with a precision better than 0.5 mu m. Time-resolved photoluminescence and photon autocorrelation measurements are used to prove the single-photon character of the emission into the propagating waveguide mode. The results obtained demonstrate that such nanostructures can be used to realize an on-chip, highly directed single-photon source with single-mode spontaneous emission coupling efficiencies in excess of beta(T) similar to 85% and the potential to reach maximum emission rates >1 GHz.