Homogeneous line broadening theory

Within the scope of the stochastic approach, there is no strict boundary between homogeneous and inhomogeneous broadening. The boundary depends on the timescale of the experiment. This approach is convenient for considering the line broadening problem in vapour or liquid phases. However, stochastic theory cannot explain the optical band shape in solids. Therefore, we shall only use a dynamical approach to the line broadening problem. 

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