Metrological characterization of a commercial single-photon source with high photon flux emission

Abstract

Abstract We present a comprehensive metrological characterization of a commercial single-photon source with high photon flux emission for use in radiometry. The source is based on an InGaAs quantum dot in a micropillar. A comparative analysis of two excitation schemes—phonon-assisted excitation and two-photon excitation—explores differences in excitation power dependence, temporal stability and single-photon purity. The commercial source exhibits excellent properties for the field of quantum radiometry, achieving simultaneously a photon flux of (17.19 ± 0.09) million photons/s for a pulse repetition rate of 79.4 MHz, and a single-photon purity of 98%. Its optical power of (3.68 ± 0.02) pW is directly determined with a traceably calibrated low-noise photodiode. The ability to directly compare the photocurrent in a low-noise photodiode with the count rate at a single-photon avalanche detector allows for a seamless transition between the classical and quantum realizations of optical power. Therefore, we were able to build another bridge between classical and quantum radiometry by using a deterministic single-photon source.