Modifying atomic collision dynamics with intense ultrashort laser pulses.

Abstract

It has been suggested that ''short'' pulses of intense laser radiation can modify atomic collision dynamics in new and interesting ways. Recent experimental results in sodium-argon vapor with 1.6-psec pulses verify the existence of such an effect, although smaller in magnitude and at somewhat higher field intensities than had been predicted from theoretical arguments. Using quantum-mechanical wave-packet propagation on a realistic potential-energy curve under the parameters of the experiment, we determine that the time between curve crossings, the standard against which pulse durations should be measured, is on the order of 0.8 psec or less. The experimental results can then be understood in the context of having used too long a pulse to have clearly observed short-pulse effects.