Microwave Induced Time-Dependent Effects in Triplet Phosphorescence

The changes in the polarization and intensity of phosphorescent emission from triplet states, induced by a resonant time dependent microwave field coupling magnetic sublevels, are described in the absence of spin–lattice relaxation. Specifically, the microwave field can be used to amplitude modulate the polarization and intensity of phosphorescence from organic molecules or to rotate the polarization vector of phosphorescence. In addition, “optical phase precession,” a phenomenon closely resembling quantum beats, is predicted. Finally, the use of adiabatic inversion of the magnetic sublevel populations to directly measure intersystem crossing is demonstrated.