3 papers
physics.optics2025
Strong-field Driven Sub-cycle Band Structure Modulation and Dephasing Control
Francis Walz, Shashank Kumar, Amirali Sharifi Olounabadi +6
Over the past decade, ultrafast electron dynamics in the solid state have been extensively studied using various strong light-matter interaction techniques, such as high-harmonic g…
physics.atom-ph2025
Broadband femtosecond lasers enable efficient two-photon excitation of the ultranarrow linewidth singlet 1s2s state in helium
Shashank Kumar, Justin D. Piel, Chris H. Greene +1
We propose a broadband, femtosecond two-photon excitation scheme for efficient population transfer to the ultra-narrow linewidth metastable state in helium. Using $12…
physics.chem-ph2025
Molecular Axis Distribution Moments in Ultrafast Transient Absorption Spectroscopy: A Path Towards Ultrafast Quantum State Tomography
Shashank Kumar, Eric Liu, Liang Z. Tan +2
In ultrafast experiments with gas phase molecules, the alignment of the molecular axis relative to the polarization of the interacting laser pulses plays a crucial role in determin…