Nanoparticles in strong laser fields: ionization control and imaging

Date

Nov 17, 2015

Time

4:40 PM - 6:10 PM

Speaker

Prof. Dr. Karl-Heinz Meiwes-Broer

Affiliation

Institute of Physics, University of Rostock

Series

TUD Physikalisches Kolloquium

Language

en

Main Topic

Physik

Other Topics

Physik

Host

Prof. Dr. Carsten Timm, Fachrichtung Physik

Description

Atomic clusters and nanoparticles in intense laser fields are a nice playground to study the non-linear coupling of electromagnetic radiation into matter. The availability of intense ultrashort laser pulses has been key to study exceptional light-matter phenomena in the strong-field regime. Exposed to strong laser fields, atomic clusters transform into a transient nanoplasma at near solid density.

The talk will focus on (a) controlling the strong-field ionization dynamics in clusters. Several means are taken to steer the electron emission, including the delay between dual fs pulses, optimized pulse shapes, and the phase control in ω/2ω and few cycle excitation. (b) Using intense XUV free electron laser fs-pulses,single particle scattering images can be achieved from silver nanoparticles in a beam, i.e., without any interaction with an environment. Highly symmetric and anisotropic features are observed, reflecting the regular shape of metal particles even with radii larger than ≈ 50 nm [1]. A variety of cluster morphologies can be identified, including truncated octahedrons, decahedrons, twinned tetrahedrons, and dodecahedrons. Excellent agreement is obtained between simulated and measured scattering images.

[1] Barke et al., The 3D-architecture of individual free silver nanoparticles captured by X-ray scattering. Nature Com. 6, 7187 (2015)

Links

• http://tu-dresden.de/veranstaltungen/termin?id=TUD56275af0d040a

Last modified: Nov 17, 2015, 8:38:03 AM