Intense laser-controlled quenching of molecular fragmentation

Abstract

We show how efficient control can be exerted on molecular dissociation by adiabatic shaping of an intense, single laser pulse in a very simplified way, involving a few parameters (e.g., peak amplitude, carrier-wave, and modulation phases and frequencies). The strategy takes advantage of an appropriate combination of basic multiphoton mechanisms: bond softening (BS), vibrational trapping (VT), and dynamical dissociation quenching (DDQ). The resulting stabilization enhancement with respect to dissociation may increase up to a factor of 5, while simultaneously inhibiting the BS mechanism and reenforcing the VT mechanism, using DDQ. The photodissociation of H{sub 2}{sup +} submitted to a uv-visible field modulated by an IR periodic envelope, on which the consequences of a DDQ-type mechanism has recently experimentally been checked, is taken as an illustrative example.