IONIZATION AND DISSOCIATION OF H2 IN INTENSE LASER FIELDS AT 1.064-MU-M, 532 NM, AND 355-NM

We present a systematic experimental study of the dissociation and ionization of molecular hydrogen in intense laser fields at three different wavelengths: 1.064m, 532 nm, and 355 nm. The light intensity ranges from 1013 W/cm2 to 1015 W/cm2. Measurements include electron spectra and angular distributions, kinetic-energy spectra and angular distributions of ion fragments, and ion dissociation fractions. We report a number of interesting and novel phenomena, including the following: above-threshold ionization to various vibrational states in the molecular ion, production of very-high-energy electrons from ionization at 1.064m, enhanced dissociation of the H2+ molecular ion via the mechanism of bond softening, above-threshold dissociation, and evidence for the alignment of the molecule in a high-intensity laser field. © 1990 The American Physical Society.