First imaging of free nanoparticles in laboratory experiment using a high-intensity laser source

In a joint research project of the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI), the Technical University (TU) Berlin and the University of Rostock, it was for the first time possible to image free nanoparticles with a high intensity laser source in a laboratory experiment. The detailed representation of these extremely small structures with the help of individual diffraction patterns has hitherto only been possible at large-scale research facilities, so-called free-electron lasers. The groundbreaking results enable the highly efficient characterization of the chemical, optical and structural properties of individual nanoparticles and have now appeared in Nature Communications. The first author of the publication is the junior scientist dr. Daniela Rupp, who carried out the project at the TU Berlin and is now building up a junior research group at the MBI.

In their laboratory experiment, the research team used helium gas, which - cooled down to very low temperatures - turns into a superfluid state and forms tiny nanodroplets during atomization. "These tiny droplets were transilluminated with ultrashort X-ray flashes and the scattered laser light recorded as a snapshot on a surface detector," explains Dr. Daniela Rupp.

"The high-intensity X-ray flashes from the laboratory laser source at the MBI have contributed to the success of the experiments, which already produce highly detailed scatter patterns with a single image," explains Dr. med. Arnaud Rouzée of the MBI. "By recording in the so-called wide-angle mode, we have identified previously unknown forms of superfluid droplets," adds Prof. Thomas Fennel from the MBI and the University of Rostock. The results of the research team open up completely new possibilities for the analysis of the structure and optical properties of small particles. They show that, thanks to state-of-the-art laser light sources, it is no longer possible to produce impressive images of the smallest material exclusively at large research facilities.

The physicist dr. Daniela Rupp worked until summer 2017 as a scientist at the Institute of Optics and Atomic Physics of the Technical University of Berlin. Now she is building a junior research group at the MBI (Leibniz-Junior Research Group), where she continues her research on single particle imaging with short and intense ultra-ultraviolet light pulses. She has received several awards including the Dissertation Prize of the AMOP section of the German Physical Society, the Carl Ramsauer Prize of the Berlin Physical Society, and the Physics Study Prize of the Wilhelm and Else Heraeus Foundation.

Original publication

Coherent diffractive imaging of single helium nanodroplets with a high harmonic generation source

D. Rupp, N. Monserud, B. Langbehn, M. Sauppe, J. Zimmermann, Y. Ovcharenko, T. Möller, F. Frassetto, L. Poletto, A. Trabattoni, F. Calegari, M. Nisoli, K. Sander, C. Peltz, M. J. J. Vrakking, T. Fennel, A. Rouzée

Nature Communications 8 (2017) 493/1-6