An evolutionary learning algorithm in conjunction with an ultrafast optical
pulse shaper was used to control vibrational motion in molecular gases at
room temperature and high pressures. We demonstrate mode suppression and en
hancement in sulfur hexafluoride and mode selective excitation in carbon di
oxide. Analysis of optimized pulses discovered by the algorithm has allowed
for an understanding of the control mechanism. (C) 2001 Elsevier Science B
.V. All rights reserved.