Freitag, 20. Januar 2017, 15:15 - 16:45 iCal


"Ultrashort Laser Ablation Dynamics and Induced Surface Structures"

Gastvortrag von PD. Dr. Andreas Assion (Spectra-Physics Vienna, Femtolasers Produktions GmbH, Wien)

Universität Wien, Chemische Institute, Seminar Raum 2 (Raum 2124), 1. Stock
Währinger Straße 42, 1090 Wien


Lasers are playing a major role in processing of disparate materials used in engineering and manufacturing. The range of applications in which they are being used is ever increasing. However, material processing with ultrafast lasers provides unique advantages like elimination of thermal diffusion and reduced heat-affected-zone (HAZ) when compared to processing with nanosecond and longer laser pulses. With short pulses, multi-photon absorption is possible which can improve the spatial resolution to exceed the diffraction limit, due to the combined nonlinearity and the threshold effect. The processes that take place when an ultrashort laser pulse irradiates a material are complex and are material dependent. The underlying physical mechanisms can be identified by studying the dynamics of particles (ions, clusters and neutrals) that emit from the material upon fs laser irradiation.

Another effect that is observed when ultrashort pulses irradiate a material is the formation of periodic structures. These laser-induced periodic surface structures (LIPSS or ripples) appear on all kinds of materials: dielectrics, semiconductors, polymers and metal surfaces, when exposed to single or multiple ultra-short laser pulses. The formed periodic structures have two sets of periods. One set of periods is close to the wavelength of the laser radiation and the other set has periods close to 1/10th of the wavelength of the incident radiation. The field has recently gained remarkable interest as they can be generated in a single-step process and allows a wide range of surface functionalization. Possible applications include colorization, control of surface wetting behavior, enhanced absorption, self cleaning properties, friction management etc. The main topics of the talk are aspects of the dynamics of ultra short pulse laser ablation and formation mechanisms of LIPSS.


Institut für Physikalische Chemie, Universität Wien


Univ.-Prof. Dr. Wolfgang Kautek
Universität Wien
Institut für Physikalische Chemie
0043 664 60277 52470