TY - JOUR A1 - Kautek, Wolfgang A1 - Pentzien, Simone A1 - Rudolph, Pascale A1 - Krüger, Jörg A1 - König, E. T1 - Laser interaction with coated collagen und cellulose fibre composites: fundamentals of laser cleaning of ancient parchment manuscripts and paper N2 - Laser cleaning of delicate biological composite materials such as ancient parchment manuscripts from the 15th and 16th century and printed paper from the 19th century is demonstrated with an ultraviolet excimer pulsed laser at 308 nm. Laser fluence levels must stay below the ablation and destruction threshold of the parchment or paper substrate, and have to surpass the threshold of the contaminant matter. Foreign layers to be removed must exhibit a higher optical density than the artifact substrates. Synthetic carbonaceous dirt modelled by water-soluble black crayons showed a characteristically weak featureless laser-induced plasma spectroscopy spectrum near the noise limit. It turned out that laser-induced plasma spectroscopy is of limited use in monitoring halting points (or etch-stops) because it relies on the destruction not only of the laterally inhomogenously distributed contaminant but also of pigment phases on a microscopically rough parchment substrate. Laser-induced fluorescence spectroscopy, however, promises to be a valuable non-destructive testing technique for etch-stop monitoring. KW - Laser KW - Parchment KW - Papery KW - Spectroscopy KW - Laser cleaning PY - 1998 SN - 0169-4332 SN - 1873-5584 VL - 127-129 SP - 746 EP - 754 PB - North-Holland CY - Amsterdam AN - OPUS4-11516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baudach, Steffen A1 - Bonse, Jörn A1 - Kautek, Wolfgang T1 - Ablation experiments on polyimide with femtosecond laser pulses N2 - Some applications of polymer films require the microstructuring of partly uneven substrates. This cannot be achieved by conventional photolithography, usually performed with ultraviolet short-pulse lasers (excimer, fourth harmonic Nd:YAG). When processing thermally sensitive or undoped polymers with low optical absorption, the use of femtosecond laser pulses can improve the ablation precision, also reducing the heat-affected zone. Therefore, a Ti:sapphire laser system was employed to perform ablation experiments on polyimide (PI). The irradiated areas were evaluated by means of optical and scanning electron microscopy. Highly oriented ripple structures, which are related to the polarization state of the laser pulses, were observed in the cavities. The relationship between the ablation threshold fluence and the number of laser pulses applied to the same spot is described in accordance with an incubation model. T2 - 5th International Conference on Laser Ablation ; COLA '99 CY - Göttingen, Germany DA - 1999-07-19 KW - Polyimide KW - Laser KW - Ablation KW - Femtosecond laser PY - 1999 DO - https://doi.org/10.1007/s003390051424 SN - 0947-8396 VL - 69 IS - 7 SP - S395 EP - S398 PB - Springer CY - Berlin AN - OPUS4-780 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kautek, Wolfgang T1 - Laserstrahlreinigung von historischem Pergament und Papier T2 - 4. Forum "Laser in der Restaurierung und Denkmalpflege" CY - Leipzig, Deutschland DA - 2000-10-27 KW - Laser PY - 2000 CY - Leipzig AN - OPUS4-903 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Reetz, Susanne A1 - Pentzien, Simone T1 - Template Electrodeposition of Nanowire Arrays on Gold Foils Fabricated by Pulsed-Laser Deposition KW - Nanodraht KW - Gold KW - Galvanisierung, elektrisch KW - Verbundwerkstoff KW - Laser KW - Impulslaser PY - 1995 SN - 0013-4686 SN - 1873-3859 VL - 40 IS - 10 SP - 1461 EP - 1468 PB - Elsevier Science CY - Kidlington AN - OPUS4-626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höpner, A. A1 - Seitz, H. A1 - Rechenberg, I. A1 - Bugge, C. A1 - Procop, Mathias A1 - Scheerschmidt, E. A1 - Queisser, A. T1 - TEM Characterization of the Interface Quality of MOVPE Grown Strained InGaAs/GaAs Heterostructures KW - TEM KW - Laser PY - 1995 SN - 1862-6300 SN - 0031-8965 VL - 150 IS - 427 SP - 427 EP - 437 PB - Wiley-VCH CY - Berlin AN - OPUS4-598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Krausz, F. T1 - Incubation of laser ablation in fused silica with 5-fs pulses N2 - Zusammenfassung The threshold fluences for laser-induced damage of fused silica with single 5-fs pulses from a Ti:sapphire laser system were determined by extrapolating the ablated volume to zero. These thresholds are about 4 times as high as the values previously obtained from multi-shot experiments. This result is interpreted in terms of an irreversible modification of the original material below the single-shot threshold (incubation). KW - Laser PY - 1999 DO - https://doi.org/10.1007/s003390051034 SN - 0947-8396 VL - 69 IS - 4 SP - 465 EP - 466 PB - Springer CY - Berlin AN - OPUS4-799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -