Theory for wavelength-resolved photon emission statistics in single-molecule spectroscopy

Abstract

We derive the moment generating function for photon emissions from a single molecule driven by laser excitation. The frequencies of the fluoresced photons are explicitly considered. Calculations are performed for the case of a two level dye molecule, showing that measured photon statistics will display a strong and non-intuitive dependence on detector bandwidth. Moreover, it is demonstrated that the anti-bunching phenomenon, associated with negative values of Mandel's Q-parameter, results from correlations between photons with well separated frequencies.