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Julia Hengster

Publications and source records attributed to Julia Hengster.

3 recordsLinked to original sources
arXiv2017

Stabilizing isolated attosecond pulse formation by dispersion tuning

The carrier envelop phase (CEP) of isolated attosecond pulses (IAPs) is theoretically and experimentally investigated based on the assumption that a significant contribution originates from the measurable CEP jitter of the driving laser. By solving the timedependent Schrödinger equation, it is demonstrated that the attosecond CEP jitter of IAPs is minimized when the driving pulse is near its Fourier limit but with slightly negative chirp. Although, at present the utilization of the CEP of IAPs has limited applications, understanding and characterization of the CEP jitter of IAPs is the first step towards exact control of the electric field of extreme ultraviolet (XUV) pulses

physics.optics↗
arXiv2017

Investigations of dynamic light scattering properties in fluorescent solution: A comprehensive study using plasmonic enhanced Flow-Cytometry

In this article we present a new diagnostic approach utilizing flow-cytometry to study compounds of nanoparticle samples in solution by analysis of their scattering patterns retrieved from the cytometric measurements. As a specific enhancement of this technique we study as well the scattering pattern of nanoparticles in a fluorescent solution (529 nm). A significant enhancement of the cytometry measurements is observed supporting an improved separation of particle formations that are clearly resolved in the cytograms. The samples in this experiment are prepared from 80 nm citrate-capped gold nanoparticles (AuNP). They are stabilized providing 2-(dimethylamino)ethanol (DMAE) in the aqueous solution. A laser diode with a wavelength of 488 nm is used as fundamental illumination for the flow-cytometry measurements (FCM). Dynamic Light Scattering (DLS) measurements are performed separately and demonstrate a very good agreement with the Flow-Cytometry measurements both of which allow to give an effective size calibration. For further analysis light transport simulations are presented. They provide information on the key-process to form the correlation of the fluorescent solutions FCM to the studied particles of interest. From this we extract the volume nature of the scattering process ensuring the correlation.

physics.optics↗
arXiv2014

Attosecond Photoscopy of Plasmonic Excitations

We propose an experimental arrangement to image, with attosecond resolution, transient surface plasmonic excitations. The required modifications to state-of-the-art setups used for attosecond streaking experiments from solid surfaces only involve available technology. Buildup and life times of surface plasmon polaritons can be extracted and local modulations of the exciting optical pulse can be diagnosed {\it in situ}.

physics.optics↗