Steps towards a tunable vacuum ultraviolet light source for TR-ARPES

We detail the steps towards a tunable vacuum ultraviolet light source for time-– and angle–resolved photo emission spectroscopy (TR-ARPES); specifically, the construction and characterization of a ytterbium–fiber based pump source, and a nonlinear broadening and compression stage using gas–filled hollow–core fiber (HCF). The ultimate goal is generating sub–30 fs pulses with photon energies between 5 eV and 11 eV via resonant dispersive wave (RDW) generation in a succeeding HCF. The interim goal discussed herein is producing 30 fs, infrared (∼ 1 µm), pulses with sufficient energy (µW level) for RDW generation. Using second harmonic generation (SHG) frequency resolved optical gating (FROG) we currently measure 174 fs, 4.0 µJ pulses. We will provide explanations for the shortcoming and suggest several possible solutions to address it.Science, Faculty ofPhysics and Astronomy, Department ofGraduat