Saturable Absorption of Free-Electron Laser Radiation by Graphite near the Carbon K-Edge.

ABSTRACT: The interaction of intense light with matter gives rise to competing nonlinear responses that can dynamically change material properties. Prominent examples are saturable absorption (SA) and two-photon absorption (TPA), which dynamically increase and decrease the transmission of a sample depending on pulse intensity, respectively. The availability of intense soft X-ray pulses from free-electron lasers (FELs) has led to observations of SA and TPA in separate experiments, leaving open questions about the possible interplay between and relative strength of the two phenomena. Here, we systematically study both phenomena in one experiment by exposing graphite films to soft X-ray FEL pulses of varying intensity. By applying real-time electronic structure calculations, we find that for lower inte

SUBMITTER: Hoffmann L 

PROVIDER: S-EPMC9549516 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature