Abstract

Collisions with cooled and trapped atoms have been the subject of intense investigation during the past years. Unprecedented details of the intermediate steps in the collision have been revealed.¹ A remarkable feature in the ultracold system is the ability to control entrance- channel scattering flux and thereby control the exit channel of the collisional encounter. Here we present the continuation of our recent work,² where photoassociative ionizations (PAI) of sodium atoms were suppressed by application of an optical field. The new experiments show that suppression of almost 100% is possible when high intensity³ is used and a remarkable dependence with the polarization of the suppressor laser field is observed and calculated. This rersult shows a deviation from the simple picture based on the Landau-Zener avoided crossing model when high intensity is used.

© 1996 Optical Society of America