Isotope effects and bond softening in intense-laser-field multiphoton dissociation of H2+

Abstract

Isotope effects in the H2+-D2+ fragmentation by intense laser fields offer the possibility of a multiphoton interpretation of the bond-softening mechanism. Surprisingly, the calculations indicate that the one-photon dissociation of D2+ is favored with respect to that of H2+. This cannot be understood, as has previously been done, by a single-photon mechanism following tunneling through a lowered potential barrier, obviously more transparent for the lighter H2+. It is rather a competition between this single-photon mechanism and a five-photon mechanism which is suggested for a more realistic interpretation. © 1994 The American Physical Society.