Seminars

# PIER Photon Science Colloquium: Stimulated X-ray emission in the condensed phase

## by Martin Beye (Helmholtz-Zentrum Berlin)

Friday, December 13, 2013 from to (Europe/Berlin)
at DESY Hamburg ( CFEL, Bldg. 99 )
 Description With the intense X-ray beams from free-electron lasers, we can systematically study condensed matter in very different core-)excitation regimes. The determining parameters are the instantaneous core hole density and the total deposited energy, that separate well-known linear processes from sequential excitations by many photons and from non-linear multi-photon processes. While some observed phenomena can be explained in the intermediate regime of sequential excitations, a wealth of novel possibilities for materials science opens in the non-linear regime. I will show examples spanning a large range of excitation densities up to the observation of stimulated X-ray emission. Future routes for merging the superior specificity of X-ray spectroscopy with the information depth of non-linear optical techniques will be discussed.