Quantum coherent diffractive imaging

Abstract

Coherent diffractive imaging (CDI) has enabled the structural analysis of individual free nanoparticles in a single shot and offers the tracking of their light induced dynamics with unprecedented spatial and temporal resolution. The retrieval of structural information from scattering images in CDI experiments is so far mostly based on the assumption of classical scattering in linear response. For strong laser fields and in particular for resonant excitations, both the linear and the classical description may no longer be valid as population depletion and stimulated emission become important. Here we develop a density matrix-based scattering model in order to include such quantum effects in the local medium response and explore the transition from linear to non-linear CDI for the resonant scattering from Helium nanodroplets. We find substantial departures from the linear response case already for experimentally reachable pulse parameters and show that non-linear spatio-temporal excitation dynamics results in rich features in the scattering, leading to the proposal of quantum coherent diffractive imaging as a promising novel branch in strong-field XUV and x-ray physics.

Attosecond technology(ies) and science

“…In addition to being of interest as a possible source of attosecond laser pulses, plasmas are also of great interest in attosecond science in and of themselves. In [195] Kruse et al report a novel computational scheme that permits the calculation of coherent diffraction images for the scattering of intense, few-femtosecond XUV pulses from sub-micron He droplets that are converted into plasmas under the influence of the incoming radiation [196]. The required XUV pulses have recently become available in the laboratory [121].…”