| One of the research goals in the DiMauro group is the application of attosecond light pulses for understanding electronic processes and for molecular imaging. The objective of this dissertation work was the construction of an attosecond beamline at The Ohio State University, and the implementation of the so-called Rabbitt technique.;The Rabbitt experiment is a pump-probe interferometer that leads to the characterization of the temporal structure of EUV (extreme ultraviolet) and soft X ray harmonics, generated using intense infrared lasers. This allows us to find the optimal conditions for generating attosecond pulses. The attosecond pulses can then be used in the same apparatus to study the dynamics of atomic processes on the attosecond timescale and for molecular imaging. The novelty of this setup is the use of long wavelength (>1000 nm) laser beams, which will generate much shorter attosecond pulses than reported so far in literature and with a central energy that can be chosen to be much higher.;One of the results of the experiment is the determination of the attochirp (i.e. the second order derivative of the harmonics' phase with respect to their frequency) scaling with the fundamental laser wavelength. The attochirp is found to have a dependence on the atomic species used to generate the harmonics. The attochirp also significantly depends on the position of the generating gas source relative to the laser focus, the pressure of the generating gas and the IR laser intensity. The influence of inner subshell electrons and the fine structure of the detection gas, secondary electrons, as well as Fano resonances in the detection gas are discussed. |
