Institute of Semiconductor- and Solid State Physics,  Johannes Kepler University Linz Upper Austrian Research, Dept. "Infrarot-Prozeßmeßtechnik" (Scientific supervisor: H. Krenn) TCE - Technical Coating Engineering GmbH., Kapfenberg, Austria (Pyrometry on hard-coatings on steel) Oregon Medical Laser Center, Portland, Oregon, USA Biomedical Photonics Department , Institute of Applied Physics, University of Berne