Parts | Days | Selection | Search | Downloads | Help
K: Fachverband Kurzzeitphysik
K 7: Laser - Systeme und Anwendungen I
K 7.2: Invited Talk
Thursday, March 13, 2008, 14:30–15:00, 3E
LIBS Micro-Analysis by Use of Tapered Optical Fibers — •Johannes Heitz1,2, Thomas Stehrer1,2, and Johannes David Pedarnig1,2 — 1Christian Doppler Laboratory for Laser-Assisted Diagnostics, Johannes Kepler University Linz, A-4040 Linz, Austria — 2Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz, Austria
Laser-induced breakdown spectroscopy (LIBS) is an increasingly used method for chemical analysis of either solid, gaseous or liquid samples (e.g. molten metal melts) [1]. We demonstrate here that LIBS can also be performed with a lateral resolution in the order of a few micrometers by employing tapered optical fibers as light guides [2]. These fiber tips were produced by wet chemical etching and approached to the surface by means of shear force detection with a piezo-electric sensor [3]. The aluminum alloy amples under investigation had an Al content of about 90 % and Si, Fe and Mg as most relevant minor components. We used a Nd:YAG laser delivering 6 ns pulses with pulse energies up to 450 mJ. Subsequently, the laser-light was frequency doubled to a wavelength of 532 nm and coupled into the fiber.
[1] J. Gruber, J. Heitz, D. Bäuerle et. al., In-situ Analysis of Metal Melts in Metallurgic Vacuum Devices by Laser-induced Breakdown Spectroscopy, Appl. Spectrosc. 58, 457 (2004); [2] T. Stehrer, J. Heitz, LIBS Micro-Analysis of solid aluminum samples by use of optical fibers as light guide, SPIE Proc. 6346, 634626 (2007); [3] G. Wysocki, J. Heitz, D. Bäuerle, Near-field optical nanopatterning of crystalline silicon, Appl. Phys. Lett. 84, 2025 (2004)