Investigation of Ultra-fast Processes with High Harmonic Generation

Abstract

Electron dynamics are on the order of picosecond to sub-femtosecond timescales. In order to probe these measurements, a sub-femtosecond resolution is required. This can be achieved with spectroscopic measurements which utilize lasers with femtosecond to attosecond pulses. In this report, x-ray excited optical luminescence with high harmonic generation as the excitation source is investigated as a means to measure the timescales of internal conversion in organic molecules and charge transfer from a zirconium oxo cluster to a fluorescent ligand. The results from the investigation of the internal conversion process revealed that XUV excited luminescence is accelerated compared to DUV excited luminescence. This is attributed to quenching due to the charging of the environment as a results of ionizing XUV photons. The investigation on the charge transfer process revealed that the luminescence originates from the zirconium oxo cluster instead of the fluorescent ligand. Further investigation into the internal conversion and charge transfer timescales require measurements on a shorter time range. This requires further optimization of the experiment setup.