Freiburg 2024 – scientific programme
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MO: Fachverband Molekülphysik
MO 2: Attosecond Physics I (joint session A/MO)
MO 2.3: Talk
Monday, March 11, 2024, 11:30–11:45, HS 1098
Controlling Photoabsorption Interferometrically with Intense Laser Pulses from Microscopic to Macroscopic Gases — •Yu He1, Shuyuan Hu1, Gergana D. Borisova1, Yizhu Zhang1,3, Marc Rebholz1, Mette B. Gaarde2, Christian Ott1, and Thomas Pfeifer1 — 1Max-Planck-Institut für Kernphysik, Heidelberg, Germany — 2Louisiana State University, Baton Rouge, USA — 3Tianjin University, Tianjin, China
Photoabsorption results from the interference between the incident field and the newly generated one radiated by the induced dipole oscillation. This dipole-emitted field can be controlled by the interplay of pulse propagation and intense laser pulses, giving rise to different absorption lineshapes. By temporally confining this new field through emptying the population of the excited state after its excitation, we achieve a local enhancement of absorbance in transient absorption spectroscopy [1,2]. In addition, in tandem with theory, we experimentally demonstrate the transition of absorption profiles from natural Lorentzian to Fano-like, which then become broader with further emergence of spectral bifurcations, finally turning back to near-Lorentzian lines in optically dense helium [3]. The integrated interferometric scenario in ultrafast absorption spectroscopy provides insights into the behavior of ensembles of dipole emitters and their temporal control. Refs: [1] He at al., Phys. Rev. Lett. 129 273201 (2022). [2] He at al., manuscript submitted (2023). [3] He at al., manuscript in preparation.
Keywords: Transient absorption spectroscopy; Propagation effects