A New Application of Laser Power Index in Multiphoton Processer:estimation of excitation cross sections

In this paper, the general characteristics of laser power index of product signal in multphoton processes were discussed and a new method to estimate excitation process by analyzing the variation of power indew with laser intensity were proposed. The validity of this method is theoretically demonstrated by means of the rate equations based upon a two-step kinetic model and some numerical and experimental results. This method could, in principle, be extended to the multiphoton process with steps more than two.