Abstract

The multiphoton ionization of molecules in strong laser fields has been investigated for over 10 years. However, the interpretation of the experiments has been complicated by the vibrational time scales of the molecules. Specifically, when a molecules is ionized to 2+ or higher, it becomes unstable and starts to dissociation. At pulse durations longer that 100 fsec the dissociation occurs while the laser pulse is still on which complicates the interpretation of the results. Thus, there is great interest in performing these experiments with as short a pulse duration as possible. To this end we have constructed an ultrashort-pulse laser system which delivers 0.5 mJ in 35 fsec with good beam quality. Ensuring the latter required the careful design of a multipass amplifier.

© 1997 Optical Society of America