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

Abstract

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 ∼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.