Intense laser control of the chemical bond

Molecular internal force fields and photofragmentation dynamics may dramati cally be affected by very strong radiative interactions, Highly non-linear field induced barrier lowering and stabilization mechanisms, either in the UV-Visible or IR excitation regimes are at the origin of the chemical bond softening and hardening processes, respectively. Field characteristics (fre quency, amplitude, phase, polarization and pulse shape) may adequately be a djusted such that, through the interplay of these complementary mechanisms, laser control scenarios are achieved. Total and partial dissociation rates , fragment's kinetic and angular distributions are among the observables th at can be controlled. After introducing the time-dependent quasi-static adi abatic states of the low frequency limit and the stationary adiabatic dress ed potentials in the Floquet frame of the high frequency limit, the feasibi lity of some laser control schemes in the photodissociation of H-2(+) and D -2(+) is illustrated in a few examples. (C) 1999 Elsevier Science B.V. All rights reserved.