Nonlinear reversal of photoexcitation on the attosecond time scale improves ultrafast X-ray diffraction images
Abstract
Abstract The complex refractive index of a material governs its light-matter interactions, with intense light fields enabling tailored nonlinear optical responses. In the X-ray regime, rapid photoionization limits the potential of nonlinear techniques by inducing irreversible electronic damage. Here we demonstrate that intense, sub-femtosecond X-ray pulses, shorter than typical Auger decay times, can partially reverse photoexcitation via stimulated emission near atomic resonances. By analyzing thousands of coherent diffraction patterns and ion spectra from neon nanoparticles exposed to sub-fs and 15-fs pulses, we observe enhanced X-ray diffraction alongside reduced energy absorption for sub-fs pulses. Theoretical modeling attributes this to dynamics akin to Rabi flopping that prolong the lifetime of resonant states and suppress electronic bleaching. These findings suggest that ultrashort, intense X-ray pulses enable active control of X-ray refractive index and damage pathways, opening avenues for improved high-resolution imaging and nonlinear spectroscopy in complex nanoscale systems.
Article Details
Authors (31)
Anatoli Ulmer
Phay J. Ho
Bruno Langbehn
Stephan Kuschel
Linos Hecht
Razib Obaid
Simon Dold
European XFEL , Holzkoppel 4 , ,
Taran Driver
Joseph Duris
Ming-Fu Lin
SLAC National Accelerator Laboratory 4 , Menlo Park, California 94025,
David Cesar
Paris Franz
Zhaoheng Guo
Philip A. Hart
Andrei Kamalov
Kirk A. Larsen
Xiang Li
Michael Meyer
Kazutaka Nakahara
Robert G. Radloff
River Robles
Lara Rönnebeck
Nick Sudar
Adam M. Summers
Linda Young
Peter Walter
James P. Cryan
Christoph Bostedt
Daniela Rupp
Agostino Marinelli
Tais Gorkhover