Berlin 2014 – scientific programme
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K: Fachverband Kurzzeitphysik
K 5: Laser-Materie-Wechselwirkung und Laseranwendungen II
K 5.2: Talk
Tuesday, March 18, 2014, 14:15–14:30, SPA SR203
Machining of Biocompatible Polymers with Shaped fs laser pulses — •Conrad Schuster1, Christoph Merschjann1, Neeke Rothe1, Steffen Fiedler1, Volkmar Senz2, Katrin Sternberg2, and Stefan Lochbrunner1 — 1Institut für Physik, Universität Rostock, Germany — 2IBMT, Universität Rostock, Germany
In contrast to nanosecond pulses, femtosecond laser pulses offer high peak intensities at low pulse energies,
thus enabling the controlled ablation of polymers without any bubbles or melting.
Via multi-photon effects transparent materials become processable as well.
Furthermore, working on the fs scale is not limited to single pulses.
Shaped pulses open up a variety of new processing parameters:
The spectrum of the single fs pulses emitted from the laser can be modulated in phase and amplitude to change the pulse duration, create double pulses or complex multi-pulse structures.
These structures can last several ps and show features on the time scale of the original pulse (here 50 fs).
We optimized the shape of the applied pulse structure for precise machining of biodegradable poly-L-lactide (PLLA) foils,
used for medical implants.
Using pulse shaping, we can precisely control the parameters of the machining process, including groove width and depth as well as the roughness of the adjacent surface.
Further, in contrast to commercial picosecond laser machining systems we could reduce the dimensions of created holes to diameters less than 10 µm.