AN APPROACH OF ESTIMATING EXCITATION CROSS-SECTIONS IN MULTIPHOTON PROCESSES

We suggest a simple approach to roughly estimate the excitation cross sections of various steps in a multiphoton ionization (or dissociation ) process by applying the measured dependence of product signal on las er intensity. The validity of this method is demonstrated theoreticall y by means of the rate equations based upon a two-step kinetic model a nd can, in principle, be extended to the multiphoton process with step s more than two. Some results of numerical test and experiment are quo ted.