Fast radiative decay of coherent exciton-polaritons in organic quantum-well structures

The radiation field in the barrier in terms of a single outgoing plane inhomogeneous EM wave that satisfies the scattering condition at infinity far from the 2D excitonic system is presented. It is found that EM emission from T and Z polariton modes can be observed with clear definition in time-resolved PL experiments and PEPI-like excitonic systems at grazing angles of emission. A very fast process with luminescence lifetimes is expected due to the high radiative decay rates of T and Z slow polaritons. The slow polaritons can be identified by angular dependence of the emission frequency, which arises from pronounced dispersion of the T and Z modes in the slow-wave region.