• laser control;
  • multiphoton process;
  • above-threshold dissociation;
  • wavepacket dynamics


We investigate multiphoton absorption, including the dissociation process in the OH molecule by means of wavepacket dynamics. The time-development scheme is the so-called split-operator method, which conserves the norm of the state vector. The resultant wavepacket involves the information of all discrete vibrational states and the dissociative continuum state substantially, so we are able to treat all the bound–bound, the bound–continuum and the continuum–continuum transitions. The energy spectra of the system under the strong laser pulse can also be obtained by the spectrum method, where the autocorrelation function of the wavepacket under consideration is Fourier transformed. First, we discuss the field intensity dependence of the population and the competition between dissociation and absorption processes in multiphoton processes of above-threshold dissociation (ATD). Then, we analyze the above-threshold dissociation due to the continuum–continuum transition in detail. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006