Radiative quantum yield of molecules in lasers with vibronic splitting in an excited electronic state

The stimulated-emission quantum yield of an electronically excited molecule is analyzed as a function of the vibrational relaxation time. Optical gain saturation and a finite lifetime of the lower laser level are taken into account. Use of the theoretical model is illustrated in the example of optimizing the parameters of a XeF laser. The method used to determine the rate constants for VT relaxation of excimer molecules is discussed.