Photon antibunching in the fluorescence of a single dye molecule embedded in a thin polymer film

We used scanning confocal microscopy to study the fluorescence from a single terrylene molecule embedded in a thin polymer film of polymethyl methacrylate, at room temperature, with a high signal-to-background ratio. The photon-pair correlation function $g^{\left(2\right)}\left(\tau \right)$ exhibits perfect photon antibunching at $\tau =0$ and a limit of 1.3, compatible with bunching associated with the molecular triplet state. Application of this molecular system to a triggered single-photon source based on single-molecule fluorescence is investigated.