Fluorescence of Oriented Molecules in a Microcavity
M.D. Barnes, C-Y. Kung, W.B. Whitten, J.M. Ramsey, S. Arnold and S. Holler
Phys. Rev. Lett. 76, 3931-3934(1996)

Fluorescence decay rate modification has been observed for molecules in liquid microspheres (3.5 to 25 Ám in diameter) where the molecular position and transition moment orientation are well defined. For small sizes (<6 Ám), the decay rates scale roughly as r^-1 and agree quantitatively with semiclassical calculations. For larger sizes (>15 Ám) where the cavity storage time and fluorescence liftime are roughly equal, an anomalous decrease in the decay rate ~30% is observed which is interpreted as a consequence of intermediate molecule-cavity coupling.