An atomic spectrum recorded with a single-molecule light source

A single molecule under cryogenic conditions allows one to realize an extremely bright and simultaneously narrow-band single-photon source. We present a review on the different excitation schemes of a single molecule and present the corresponding single-photon nature of the emitted light. Single-molecule spectroscopy has been recently interlinked with atomic spectroscopy. This optical interconnect among the different quantum systems might be enhanced by a so-called Faraday anomalous dispersion optical filter—an ideal tool for many experiments in quantum optics. We introduce our theoretical and experimental approach on these filters which are based on hot atomic sodium vapor. The electrical tunability together with the brightness of a single molecule allows us to record a full atomic spectrum of this filter with the single photons originating from a single-molecular emitter.