Suppression of background emission for efficient single-photon generation in micropillar cavities

We optimize the efficiency of a quantum-dot-based micropillar single-photon source by minimizing the spontaneous emission into unwanted background modes. We perform a numerical investigation of the background emission, where we identify a semi-periodic enhancement with the diameter. At these peaks of the background emission, the efficiency is reduced by similar to 20%, and we show how this reduction can be avoided simply by choosing a diameter away from the peaks. Finally, we analyze the discrepancy between the Purcell factor estimated from experimental lifetime measurements and the true Purcell factor.

Automated summary

By optimizing the efficiency of a quantum-dot-based micropillar single-photon source, we identified periodic enhancement in background emission with the diameter, which can reduce the efficiency by around 20%. Choosing a diameter away from these peaks can avoid this reduction. Additionally, discrepancy between experimentally estimated Purcell factor and true Purcell factor was analyzed.