Design and implementation of a monochromatic high harmonic generation light source at 100 kHz and its application to time- and angle-resolved photoelectron spectroscopy on Bi2Se3

Abstract

Besides the interest in many industrial applications, the development of new laser systems is important to study electronic properties of materials like, e.g. carrier lifetimes and mobility. Such physical properties can be observed with pulsed laser light sources employed in a pump-probe scheme. Angle-resolved photoelectron spectroscopy (ARPES) is an experimental technique to map the electron distribution of crystals. The first Brillouin zone is the smallest unit of the reciprocal space and represents the complete solid. To cover the full Brillouin zone, extreme ultraviolet (XUV) photon energies are needed. If ARPES is employed in a pump-probe scheme, the real-time evolution of the band structure can be observed. Therefore, a pulsed XUV light source provides the foundation to observe the temporal evolution of the electron distribution of the full first Brillouin zone. The main objective of this thesis is the design and implementation of a high harmonic (HHG) light source with high repetition rate in combination with the photoemission setup TREx. For this purpose, the second harmonic from our femtosecond Ti:sapphire laser system serves as driving laser to generate the 5th harmonic with 15 eV photons in Ar+ gas at a repetition rate of 100 kHz. If the fundamental and the XUV pulses are employed in a pump-probe scheme, it is possible to observe charge carrier dynamics in materials with time- and angle-resolved photoelectron spectroscopy (trARPES).