Speaker
Description
We have built a 800 kHz high-power pump-probe femtosecond laser system for time-resolved photoemission orbital tomography experiments. It is designed to observe the excited-state orbitals of molecular monolayers adsorbed on a substrate. The pump leg uses commercial OPAs to generate excitation wavelengths from 325-450 nm and 630 - 900 nm with pulse energies around 1 μJ and includes a path for normal incidence pumping of the sample. For the probe beam, we use a commercial Multi-Pass Cell filled with Ar to compress the 1030 nm beam for frequency doubling and prism compression of the 515 nm as the fundamental for High Harmonic Generation, with a pulse energy greater than 30 μJ. Based on the setup in Marburg [1], we focus the 515 nm beam into an Ar jet delivered by a 30 um opening capillary, producing a strong 26.5 eV harmonic that enables access to a large momentum range for photoemission orbital tomography.
References:
[1] Heyl, C. et al., J. Phys. B 45, 074020 (2012).