Ionization and dissociation ofH2in intense laser fields at 1.064 μm, 532 nm, and 355 nm

Abstract

We present a systematic experimental study of the dissociation and ionization of molecular hydrogen in intense laser fields at three different wavelengths: 1.064 μm, 532 nm, and 355 nm. The light intensity ranges from ${10}^{13}$ W/${\mathrm{cm}}^2$ to ${10}^{15}$ W/${\mathrm{cm}}^2$. 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 1.064 μm, enhanced dissociation of the ${\mathrm{H}}_2^{+}$ 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.