Steering dissociation of Br2 molecules with two femtosecond pulses via wave packet interference.

The dissociation dynamics of Br₂ molecules induced by two femtosecond pump pulses are studied based on the calculation of time-dependent quantum wave packet. Perpendicular transition from X ¹Σ_g⁺ to A ³Π_1u⁺ and ¹Π_1u⁺ and parallel transition from X ¹Σ_g⁺ to B ³Π_0u⁺, involving two product channels Br (²P_3/2)+Br (²P_3/2) and Br (²P_3/2)+Br^* (²P_1/2), respectively, are taken into account. Two pump pulses create dissociating wave packets interfering with each other. By varying laser parameters, the interference of dissociating wave packets can be controlled, and the dissociation probabilities of Br₂ molecules on the three excited states can be changed to different degrees. The branching ratio of Br^*/(Br+Br^*) is calculated as a function of pulse delay time and phase difference. [ABSTRACT FROM AUTHOR]