QIPIRC

In this APL the authors reported on the generation of single photons in the blue spectral region around 440nm from a single InGaN/GaN quantum dot. The collection efficiency was enhanced by embedding the quantum dot layer in the middle of a low-Q microcavity. The micro-photoluminescence is observed to be ~10 times stronger than typical InGaN quantum dot emission without a cavity, with the emission measured at 2000 counts per second on our CCD. The measurements were performed using nonlinear excitation spectroscopy in order to suppress the background emission from the underlying wetting layer. Hanbury-Brown and Twiss measurements then showed that the emission was indeed that of a single photon source, since measurements on several QDs in this sample always produced values for g⁽²⁾(0) of less than 0.3.

The photon correlation spectrum (black trace) of one of our quantum dots is shown in the figure below. The measured correlation spectrum of the laser light (red trace) is also shown for reference.