Regensburg 2025 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 23: Poster Ultrafast Electron Dynamics
O 23.11: Poster
Montag, 17. März 2025, 18:00–20:00, P2
table-top source for x-ray absorption spectroscopy with photon energies upto 350 eV — •Rajdwip Bhar, Oscar A. Naranjo-Montoya, Lukas Kalkhoff, Marika Schleberger, Heiko Wende, Alexander Tarasevitch, and Uwe Bovensiepen — University of Duisburg-Essen, Duisburg, Germany
Material science research aims to understand electronic properties and dynamics of complex materials. Performing pump-probe experiments using optical pump and x-ray probe enables capturing element-specific snapshots of the pump induced changes in a material. This contribution describes the development of a tabletop soft x-ray spectroscopy setup based on high harmonic generation using noble gases in a hollow core waveguide (HCW) [1].
To generate high harmonics with higher photon energies, a near-infrared driving laser source based on optical parametric chirped-pulse amplification (OPCPA) was developed [2]. Starting with an 800 nm seed and a 1030 nm pump, the OPCPA generates 1.5 µ m and 3 µ m pump pulses with pulse energies of 1.8 mJ and 0.8 mJ, respectively. The 1.5 µ m pulses, compressed to ∼ 40 fs using chirped mirrors, pump the HCW, generating harmonics that reach photon energies up to 350 eV. Near-edge x-ray absorption spectroscopy at the B K-edge in crystalline boron and hexagonal boron nitride (hBN) samples was performed, showing excellent agreement with literature data.
1O. A. Naranjo-Montoya et al., Review of Scientific Instruments 95, 103001 (2024).
2M. Bridger et al., Opt. Express 27, 31330-31337 (2019).
Keywords: X-ray absorption spectroscopy; High harmonic generation; Optical parametric chirped pulse amplification