Photoelectron and photoion spectroscopy of atoms, nanoparticles, and nanoplasmas irradiated with strong femtosecond laser fields

<p>Modern femtosecond lasers can produce pulses of light that are shorter than the vibrational\&nbsp;<span style="font-size: 13px; line-height: 1.6em;">periods in molecules and have electric fields stronger than the Coulomb field that binds electrons\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">in atoms. These short-pulse lasers enable the observation of chemical reactions, the production\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">of attosecond bursts of high-energy photons, and the precision-machining of solid materials with\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">minimal heat transport to the material. In this thesis, I describe three experiments that provide new\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">insight into strong-field (1014 Watts/cm²) femtosecond laser-matter interactions in three important\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">regimes. First, I discuss the strong-field ionization of gas-phase atoms, identify a new structure in\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">the photoelectron angular distribution of xenon gas, and explain this structure by developing an\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">intuitive wave interference model. Second, I describe a new method to perform photoelectron and\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">photoion spectroscopy on single, isolated nanoparticles and demonstrate this technique by observing\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">the directional ion ejection that takes place in the laser ablation of nanostructures. Finally, I\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">present the first experimental observations of shock wave propagation in nanoscale plasmas. These\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">findings will guide future efforts to probe the structure and dynamics of atoms and molecules on\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">the femtosecond timescale, design nanomaterials that enhance light on the subwavelength scale, and\&nbsp;</span><span style="font-size: 13px; line-height: 1.6em;">produce high-energy ions from plasmas.</span></p>