Cavity-enhanced blue single-photon emission from a single In Ga N ∕ Ga N quantum dot

The authors report on the generation of single photons in the blue spectral region from a single In Ga N ∕ Ga N quantum dot. The collection efficiency was enhanced by embedding the quantum dot layer in the middle of a low- Q microcavity. The microphotoluminescence is observed to be approximately ten times stronger than typical InGaN quantum dot emission without a cavity. The measurements were performed using nonlinear excitation spectroscopy in order to suppress the background emission from the underlying wetting layer.