Fluorescence of oriented molecules in a microcavity

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