MULTIPHOTON DISSOCIATION OF A DIATOMIC MOLECULE INCLUDING THE EFFECTS OF THE CONTINUUM

The dissociation of a diatomic molecule via the electromagnetic excitation of its vibrations is analyzed by a direct solution of the Schrodinger equation in the energy representation of the uncoupled molecule fully including the effects of the continuum. Using a Morse potential, all dipole matrix elements are obtained analytically. We give exact results for the bound-continuum matrix elements and semiclassical results for the continuum-continuum matrix elements corrected for the diverging density of states near the dissociation energy. We compute dissociation probabilities and the form of the excited wave packets in the bound and the unbound subspaces of the uncoupled molecule. The influence of a smooth switch-on and switch-off of the electromagnetic field is also analyzed. Our results are compared with and interpreted by the help of a simple Poincare map ("Morse map") derived in earlier work.