Emission Detection of Optical Coherence: Optical Dephasing and Radiationless Relaxations in Molecular Crystals

Abstract

The phenomenological understanding for the decay of excited levels following incoherent optical excitation is well-known since 1930, when Weisskopf and Wigner showed that the addition of a damping matrix to the Schrödinger equation gives a Lorentzian resonance centered around the transition frequency w_0 = E_0/h. One might therefore conclude that careful measurements of the linewidth of optical transitions will give the dynamics of excited levels. Unfortunately, these levels are not isolated from the rest of the ensemble which may or may not be "homogeneous".

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