Triggered Source of Single Photons based on Controlled Single Molecule Fluorescence

We use the method of adiabatic following to prepare a single molecule in its fluorescing excited state. Spontaneous emission from this state gives rise to a single photon. With our current experimental conditions, up to $74\%$ of the sweeps lead to the emission of a single photon. Since the adiabatic passage is done on command, the molecule performs as a high rate source of triggered photons. The experimental results are in quantitative agreement with quantum Monte Carlo simulations.