Calculation of fluorescence rate constants from absorption spectra

3 Calculation of Fluorescence Rate Constants from Absorption Spectra 

In addition to the spontaneous emission of excited molecules, fluorescence and phosphorescence (Section 2.1.1), the interaction of electromagnetic radiation with excited molecules gives rise to stimulated emission, the microscopic counterpart of (stimulated) absorption. Albert Einstein derived the existence of a close relationship between the rates of absorption and emission in 1917, before the advent of quantum mechanics (see Special Topic 2.1). 

Special Topic 2.1 Einstein coefficients of absorption and emission 

Bnm Einstein s coefficient of (stimulated) absorption Bmn Einstein s coefficient of stimulated emission Amn Einstein s coefficient of spontaneous emission 

The frequency distribution p = dp/dv of a black-body radiator is given by Planck s law (Equation 2.6)  

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