Local control of molecular fragmentation: The role of orientation

Local control theory, where the instantaneous response of a system to an external field determines the control field, is employed for the purpose of inducing molecular fragmentation processes via infrared excitation. In particular, the effects of the orientational motion are investigated and compared with the idealized case of a frozen rotation. It is shown that the rotational degree of freedom is crucial for the applicability of the employed local control algorithm. The addition of an additional static electric field which induces a molecular preorientation offers an efficient way for the local control. In particular, with increasing static field strength, the fragmentation yield approaches unity so that the idealized rotationless case is recovered. Numerical results are presented for the NaI molecule. (c) 2005 American Institute of Physics.