Microcavity-controlled single-molecule fluorescence.

We present for the first time cavity-controlled fluorescence spectra and decay curves of single dipole emitters interacting at room temperature with the first longitudinal mode of a Fabry-Perot microcavity offering a lambda/2-spacing between its silver mirrors. The spontaneous emission rate of individual dye molecules was found to be enhanced by the Purcell effect by up to three times compared to the rate in free space, in agreement with theoretical predictions. Moreover, our new microcavity design was found to provide long-term stability and single-molecule sensitivity under ambient conditions for several months without noticeable reduction of the cavity-Q value. We consider this as a significant advance for single-photon sources operating at room temperature.