Erlangen 2022 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
K: Fachverband Kurzzeit- und angewandte Laserphysik
K 7: Laser-Beam Matter Interaction - Laser Applications II
K 7.3: Vortrag
Donnerstag, 17. März 2022, 14:30–14:45, K-H4
Effect of pre-excited charge carriers on high harmonic generation in silicon — •Pawan Suthar1, František Trojánek1, Petr Malý1, Thibault Derrien2, and Martin Kozák1 — 1Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 12116 Prague 2, Czech Republic — 2HiLASE Centre, Institute of Physics, Academy of Science of the Czech Republic, Za Radnicí 828/5, 25241 Dolní Břežany, Czech Republic
High harmonic generation (HHG) in solids is a highly nonlinear optical process, in which electron-hole pairs are created via quantum tunneling, coherently accelerated and then recombined by the strong electric field of a non-resonant laser pulse. Here we study how the HHG yield in crystalline silicon is influenced by scattering of coherent wave packets by charge carriers resonantly pre-excited to the conduction and valence bands using a pump-probe like setup. The HHG is driven by few-cycle mid-infrared probe pulses with central photon energy of 0.61 eV and its spectrum and yield are characterized as functions of the time delay after a pump pulse, which resonantly excites carriers in silicon via direct (photon energy of 3.8 eV) or indirect (1.9 eV) transitions. We find that the HHG yield changes differently for different orientations of linear polarization of the mid-infrared pulse with respect to crystallographic orientation of silicon, for different photon energies of the resonant pump and that the response of each harmonic order differs. These results emphasize the role of band structure and Coulomb interactions between carriers in the HHG process.