TY - CONF A1 - Krüger, Jörg A1 - Dufft, Daniela A1 - Koter, Robert A1 - Hertwig, Andreas T1 - Femtosecond laser-induced damage of gold films T2 - E-MRS 2006 Spring Meeting, Symposium H T2 - E-MRS 2006 Spring Meeting, Symposium H CY - Nice, France DA - 2006-05-29 PY - 2006 AN - OPUS4-12252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Dufft, Daniela A1 - Koter, Robert A1 - Hertwig, Andreas T1 - Femtosecond laser-induced damage of gold films JF - Applied surface science N2 - Single- and multi-shot ablation thresholds of gold films in the thickness range of 31–1400 nm were determined employing a Ti:sapphire laser delivering pulses of 28 fs duration, 793 nm center wavelength at 1 kHz repetition rate. The gold layers were deposited on BK7 glass by an electron beam evaporation process and characterized by atomic force microscopy and ellipsometry. A linear dependence of the ablation threshold fluence Fth on the layer thickness d was found for d ≤ 180 nm. If a film thickness of about 180 nm was reached, the damage threshold remained constant at its bulk value. For different numbers of pulses per spot (N-on-1), bulk damage thresholds of ~0.7 J cm-2 (1-on-1), 0.5 J cm-2 (10-on-1), 0.4 J cm-2 (100-on-1), 0.25 J cm-2 (1000-on-1), and 0.2 J cm-2 (10000-on-1) were obtained experimentally indicating an incubation behavior. A characteristic layer thickness of Lc ˜ 180 nm can be defined which is a measure for the heat penetration depth within the electron gas before electron–phonon relaxation occurs. Lc is by more than an order of magnitude larger than the optical absorption length of α-1 ˜ 12 nm at 793 nm wavelength. KW - Single- and multi-shot ablation KW - Ti:sapphire laser KW - Gold films PY - 2007 SN - 0169-4332 SN - 1873-5584 VL - 253 IS - 19 SP - 7815 EP - 7819 PB - North-Holland CY - Amsterdam AN - OPUS4-15686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser-assisted photovoltaic bottom-up strategies N2 - A promising technology in photovoltaics is based on micro-concentrator solar cells, where the photovoltaic active area is realized as an array of sub-millimeter sized thin-film solar cells. Different approaches to produce micro-sized precursors of CIGSe absorbers on molybdenum are presented using 30-fs laser pulses at 790 nm wavelength. On the one hand, a multi pulse surface structuring of the molybdenum or the underlying glass substrate and a subsequent physical vapor deposition (PVD) process were used for a site-selective aggregation of indium droplets. On the other hand, a single pulse laser-induced forward transfer (LIFT) was utilized to selectively deposit combined copper/indium/gallium precursor pixels on the molybdenum back contact of the solar cell. It was demonstrated that a postprocessing of the laser-generated micro-sized precursors results in an array of working CIGSe solar cells with an efficiency of 2.9% for 1 sun Illumination. T2 - Leibniz-Institut für Oberflächenmodifizierung (IOM), Institutskolloquium CY - Leipzig, Germany DA - 29.11.2018 KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - CIGSe KW - Micro solar cell KW - Light concentration PY - 2018 AN - OPUS4-46831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Andree, Stefan A1 - Heidmann, B. A1 - Bonse, Jörn A1 - Eylers, K. A1 - Ernst, O. A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser-assisted fabrication of chalcopyrite micro-concentrator photovoltaics JF - Beilstein journal of nanotechnology N2 - Micro-concentrator solar cells offer an attractive way to further enhance the efficiency of planar-cell technologies while saving absorber material. Here, two laser-based bottom-up processes for the fabrication of regular arrays of CuInSe2 and Cu(In,Ga)Se2 microabsorber islands are presented, namely one approach based on nucleation and one based on laser-induced forward transfer. Additionally, a procedure for processing these microabsorbers to functioning micro solar cells connected in parallel is demonstrated. The resulting cells show up to 2.9% efficiency and a significant efficiency enhancement under concentrated Illumination. KW - Chalcopyrite KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - Micro-concentrator solar cell KW - Photovoltaics PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-470026 DO - https://doi.org/10.3762/bjnano.9.281 SN - 2190-4286 VL - 9 SP - 3025 EP - 3038 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-47002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Griepentrog, Michael A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Femtosecond laser texturing of surfaces for tribological applications JF - Materials N2 - Laser texturing is an emerging technology for generating surface functionalities on basis of optical, mechanical, or chemical properties. Taking benefit of laser sources with ultrashort (fs) pulse durations features outstanding precision of machining and negligible rims or burrs surrounding the laser-irradiation zone. Consequently, additional mechanical or chemical post-processing steps are usually not required for fs-laser surface texturing (fs-LST). This work aimed to provide a bridge between research in the field of tribology and laser materials processing. The paper reviews the current state-of-the-art in fs-LST, with a focus on the tribological performance (friction and wear) of specific self-organized surface structures (so-called ripples, grooves, and spikes) on steel and titanium alloys. On the titanium alloy, specific sickle-shaped hybrid micro-nanostructures were also observed and tribologically tested. Care is taken to identify accompanying effects affecting the materials hardness, superficial oxidation, nano- and microscale topographies, and the role of additives contained in lubricants, such as commercial engine oil. KW - Femtosecond laser processing KW - Surface texture KW - Laser-induced periodic surface structures (LIPSS) KW - Friction KW - Wear PY - 2018 UR - http://www.mdpi.com/1996-1944/11/5/801 DO - https://doi.org/10.3390/ma11050801 SN - 1996-1944 VL - 11 IS - 5 SP - 801, 1 EP - 19 PB - MDPI AG CY - Basel, Switzerland AN - OPUS4-44905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Spielmann, C. T1 - Femtosecond Laser Technology in Use: Safety Aspects - A Detailed Study compares different Materials for Eye Protection JF - Laser-Technik-Journal N2 - In recent years, femtosecond lasers matured from sensitive research setups to turnkey systems for an increasing number of applications. Now that running an ultra-short pulse laser system needs no longer a specialized scientist, safety issues become more crucial. Ultrashort laser pulses have extremely high peak powers and even scattered radiation may possess severe risks to the unprotected eye. Accordingly, special protection schemes are necessary for these unique laser systems. PY - 2008 DO - https://doi.org/10.1002/latj.200790209 SN - 1613-7728 VL - 5 IS - 1 SP - 48 EP - 52 PB - Wiley-VCH CY - Weinheim AN - OPUS4-16471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Andree, Stefan A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Bonse, Jörn A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies T2 - Tagungsband zur 10. Mittweidaer Lasertagung N2 - A promising technology in photovoltaics is based on micro-concentrator solar cells, where the photovoltaic active area is realized as an array of sub-millimeter sized cells onto which the incident light is focused via microlenses. This approach allows to increase the cell efficiency and to realize much more compact modules compared to macroscopic concentrator devices. At the same time, expensive raw materials can be saved, which is of interest, for example, with respect to indium in the case of copper-indium-gallium-diselenide (CIGSe) thin film solar cells. Two methods to produce micro-sized precursors of CIGSe absorbers on molybdenum are presented using 30-fs laser pulses at 790 nm wavelength. On the one hand, a multi pulse surface structuring of the molybdenum film or the underlying glass substrate and a subsequent physical vapor deposition were used for a site-selective aggregation of indium droplets. On the other hand, a single pulse laser-induced forward transfer was utilized to selectively deposit combined copper-indium precursor pixels on the molybdenum back contact of the solar cell. Post-processing (selenization, isolation, contacting) of the laser-generated micro-sized precursors results in functional CIGSe solar cells. T2 - 10. Mittweidaer Lasertagung CY - Mittweida, Germany DA - 16.11.2017 KW - Copper indium gallium diselenide (CIGSe) KW - Micro solar cell KW - Femtosecond laser KW - Laser ablation KW - Laser-induced forward transfer (LIFT) PY - 2017 SN - 1437-7624 VL - 2 SP - 1 EP - 4 PB - Hochschule Mittweida CY - Mittweida AN - OPUS4-42988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Andree, Stefan A1 - Knak, Alena A1 - Bonse, Jörn A1 - Symietz, Christian A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Boeck, T. A1 - Heidmann, B. A1 - Kämmer, S. A1 - Schmid, M. T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies N2 - A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass using 30-fs laser pulses at 790 nm wavelength. The indium islands can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide (CIGSe) used in photovoltaics. Molybdenum is the standard back contact material of CIGSe solar cells. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. T2 - 7th European Conference on Applications of Femtosecond Lasers in Materials Science (FemtoMat 2017) CY - Mauterndorf, Austria DA - 20.03.2017 KW - Femtosecond laser KW - Copper-indium-gallium-diselenide KW - CIGSe KW - Indium preferential nucleation KW - Photovoltaics PY - 2017 AN - OPUS4-39599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser pulses for photovoltaic bottom-up strategies N2 - A bottom-up approach to produce arrays of indium islands on a molybdenum layer on glass using 30-fs laser pulses at 790 nm wavelength is presented. These islands can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide (CIGSe) used in photovoltaics. Molybdenum is the standard back contact material of CIGSe solar cells. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. T2 - 10. Mittweidaer Lasertagung CY - Mittweida, Germany DA - 16.11.2017 KW - Copper-indium-gallium-diselenide KW - CIGSe KW - Femtosecond laser KW - Micro solar cell KW - Laser ablation PY - 2017 AN - OPUS4-42987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Hertwig, Andreas A1 - Koter, Robert A1 - Weise, Matthias A1 - Beck, Uwe A1 - Reinstädt, Philipp A1 - Griepentrog, Michael A1 - Krüger, Jörg A1 - Picquart, M. A1 - Haro-Poniatowski, E. T1 - Femtosecond laser pulse irradiation effects on thin hydrogenated amorphous carbon layers JF - Applied physics A N2 - The irradiation of ~0.9-µm-thick hydrogenated amorphous carbon (a-C:H) layers deposited on silicon substrates with single femtosecond (fs) laser pulses (35 fs pulse duration, 790 nm centre wavelength) in air is studied experimentally. Irradiation spots have been generated with different peak fluences and subsequently investigated by optical topometry, micro Raman spectroscopy and microscale mechanical indentation in order to evaluate their microscopic, topographical, structural and mechanical properties (e.g. elastic modulus). By this multi-method approach, a clear separation of different effects (delamination and graphitisation) becomes possible. The joint application of mechanical and spectroscopic techniques provides unique insights into the effects of the fs-laser radiation on the carbon layer. PY - 2013 DO - https://doi.org/10.1007/s00339-012-7170-5 SN - 0947-8396 VL - 112 IS - 1 SP - 9 EP - 14 PB - Springer CY - Berlin AN - OPUS4-28629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baudach, Steffen A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Femtosecond Laser Processing of Soft Materials JF - R¯ez¯a-kenky¯u = Review of laser engineering KW - Femtosecond pulse laser KW - Laser processing KW - Polymer ablation KW - Nanostructures PY - 2001 SN - 0387-0200 VL - 29 IS - 11 SP - 705 EP - 709 PB - Gakkai CY - Suita AN - OPUS4-6006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kautek, Wolfgang A1 - Martin, Sven A1 - Krüger, Jörg A1 - Lenzner, Matthias A1 - Fiedler, A. ED - Meunier, M. T1 - Femtosecond laser multi-pulse interaction with optical filters and fabrics T2 - Physics and chemistry of advanced laser materials processing N2 - Optical filters and fabrics are important parts of laser safety equipment such as goggles and curtains. A choice of these materials with varying absorption spectra is investigated with respect to their resistance to Ti:sapphire femtosecond laser radiation (800 nm wavelength, 1 kHz repetition rate). Pulse durations down to 30 fs and multiple-pulse irradiation conditions are employed to evaluate technically relevant damage thresholds. The ablation threshold fluences of the absorbing filters are comparable to those observed for transparent materials with 30-fs-pulses. These investigations together with scanning electron microscopy of the surface morphology after laser treatment provide insight into the interaction mechanism of the short pulses with the materials. T2 - Symposium D - European Materials Research Society CY - Strasbourg, France DA - 2002-06-18 PY - 2002 UR - http://www.emrs-strasbourg.com/files/pdf/2002_SPRING/02_Prog_Dv2.pdf N1 - Serientitel: Applied surface science – Series title: Applied surface science VL - 208/209.2003,1 IS - 1 SP - 1(?) PB - Elsevier CY - Amsterdam AN - OPUS4-1730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond Laser Micromachining: Potentials, Applications, Safety Aspects T2 - Materials Seminar Series, Paul Scherrer Institut T2 - Materials Seminar Series, Paul Scherrer Institut CY - Villigen, Switzerland DA - 2003-05-19 PY - 2003 AN - OPUS4-4360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bonse, Jörn A1 - Baudach, Steffen A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Phipps, C. T1 - Femtosecond laser micromachining of technical materials T2 - High-power laser ablation III N2 - Micromachining experiments were performed with Ti:sapphire laser pulses (130 fs - 150 fs, 800 nm, approximately 10 Hz) in air. Employing the direct focusing technique, highly absorbing titanium nitride (TiN) and weakly absorbing polyimide (PI) and polymethylmethacrylate (PMMA) served as target materials. The lateral and vertical precision of the laser ablation and morphological features were characterized by scanning force (SFM), scanning electron (SEM) and optical microscopy. For TiN, incubation can be observed, i.e. the single-pulse surface damage threshold (0.26 J/cm2) is by a factor of two greater than the threshold for 100 pulses. Ablation rates below 10 nm per pulse can be achieved. The evolution of sub-wavelength ripples is presented in dependence on pulse number and laser fluence, respectively. The incubation behavior of the polymers can be described by an accumulation model as for TiN. Experiments on PI with varying focal lengths result in the same modification thresholds. Different polarization states of light (linear, circular) lead to a variation of the ablation rate and to various morphological patterns in the ablation craters (wavelength ripples, cones). Swelling of PMMA occurred at fluences below the ablation threshold. T2 - 3rd SPIE's International Conference on High-Power Laser Ablation CY - Santa Fe, NM, USA DA - 24.04.2000 KW - Ablation KW - Femtosecond pulse laser KW - Laser processing KW - Micromachining KW - Polymer KW - Titanium nitride KW - Ripples PY - 2000 SN - 0-8194-3700-X DO - https://doi.org/10.1117/12.407346 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 4065 SP - 161 EP - 172 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser micromachining N2 - The presentation reviews femtosecond laser ablation experiments on metals, semiconductors, dielectrics, and biological materials. T2 - 19th Erwin Schrödinger Colloquium CY - Vienna, Austria DA - 24.09.2018 KW - Laser ablation KW - Laser micromachining KW - Femtosecond laser KW - Ultrashort pulse laser PY - 2018 AN - OPUS4-46075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Femtosecond laser interactions with dielectrics and polymers T2 - 4th Users Meeting of the European Network Laserlab-Europe T2 - 4th Users Meeting of the European Network Laserlab-Europe CY - Madrid, Spain DA - 2007-11-28 PY - 2007 AN - OPUS4-16071 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Femtosecond laser interaction with silicon under water confinement JF - Thin solid films N2 - Femtosecond laser interaction with silicon was investigated in water and in air, with 130-fs laser pulses at 800 nm wavelength. Under water confinement, higher modification thresholds, lower ablation depths and similar incubation factors were found in comparison to the dry experiment. Morphological features of the laser-induced cavities also differed. In contrast to air experiments, debris redeposition was negligible, while the ablated material remained suspended in the water layer phase. Underwater cavities obtained at high fluences and high number of pulses per spot showed anomalous profiles, consistent with a strong spatial deformation of the laser beam coupled into the target. Ripples formed at the edges of the modified area showed varying spacings: f100 and f700 nm for water and air experiments, respectively. Differences to the air experiment were related to a complex combination of fluence-dependent non-linear effects occurring in the water layer and to pulse-number-dependent shielding effects induced by cavitation bubbles and suspended ablated material. KW - Laser ablation KW - Silicon KW - Solid electrolyte interface KW - Water PY - 2004 DO - https://doi.org/10.1016/j.tsf.2004.04.043 SN - 0040-6090 VL - 467 IS - 1-2 SP - 334 EP - 341 PB - Elsevier CY - Amsterdam AN - OPUS4-4008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martin, Sven A1 - Krüger, Jörg A1 - Hertwig, Andreas A1 - Fiedler, A. A1 - Kautek, Wolfgang T1 - Femtosecond laser interaction with protection materials JF - Applied surface science N2 - Textile, aluminium and polyethylene used as components in laser protection curtains were investigated with respect to their ablation behaviour. Employing 33-fs pulses (800 nm wavelength, 1 kHz repetition rate), ex situ geometrical measurements of the ablation cavities and in situ acoustic investigations with a microphone were performed to determine the ablation thresholds in the single- and multi-pulse cases. The acoustical method proved advantageous for complex surface morphologies and/or single laser pulse interactions. Incubation phenomena can be observed for all the materials studied. Technically relevant multi-pulse ablation thresholds are presented and are compared with the single-pulse (1-on-1) irradiation. KW - Damage KW - Femtosecond laser ablation KW - Laser safety KW - Threshold KW - Aluminium KW - Textile PY - 2003 DO - https://doi.org/10.1016/S0169-4332(02)01392-2 SN - 0169-4332 SN - 1873-5584 VL - 208-209 SP - 333 EP - 339 PB - North-Holland CY - Amsterdam AN - OPUS4-11546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Symietz, Christian T1 - Femtosecond laser induced fixation of calcium alkali phosphate ceramics on titanium alloy implant material T2 - EMN Meeting on Biomaterials T2 - EMN Meeting on Biomaterials CY - Beijing, China DA - 2015-04-10 PY - 2015 AN - OPUS4-33097 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Symietz, Christian A1 - Lehmann, Erhard A1 - Gildenhaar, Renate A1 - Krüger, Jörg A1 - Berger, Georg T1 - Femtosecond laser induced fixation of calcium alkali phosphate ceramics on titanium alloy bone implant material JF - Acta biomaterialia N2 - Femtosecond lasers provide a novel method of attaching bioceramic material to a titanium alloy, thereby improving the quality of bone implants. The ultrashort 30 fs laser pulses (790 nm wavelength) penetrate a thin dip-coated layer of fine ceramic powder, while simultaneously melting a surface layer of the underlying metal. The specific adjustment of the laser parameters (pulse energy and number of pulses per spot) avoids unnecessary melting of the bioactive calcium phosphate, and permits a defined thin surface melting of the metal, which in turn is not heated throughout, and therefore maintains its mechanical stability. It is essential to choose laser energy densities that correspond to the interval between the ablation fluences of both materials involved: about 0.1-0.4 J cm-2. In this work, we present the first results of this unusual technique, including laser ablation studies, scanning electron microscopy and optical microscope images, combined with EDX data. KW - Bone implant KW - Bioceramic coating KW - Titanium KW - Calcium phosphate KW - Femtosecond laser PY - 2010 DO - https://doi.org/10.1016/j.actbio.2010.02.016 SN - 1742-7061 VL - 6 IS - 8 SP - 3318 EP - 3324 PB - Elsevier CY - Amsterdam AN - OPUS4-21446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Jörg A1 - Lenzner, Matthias A1 - Martin, Sven A1 - Lenner, M. A1 - Spielmann, C. A1 - Fiedler, A. A1 - Kautek, Wolfgang ED - Phipps, C. R. T1 - Femtosecond laser induced damage in absorbing filters used for laser protection T2 - High-power laser ablation IV N2 - Damage experiments of absorbing filters (Schott BG18 and BG36) were performed with Ti:sapphire laser pulses with durations from 30 fs to 340 fs (800 nm, 1 kHz) in air. The direct focusing technique was employed under single- and multi-pulse irradiation conditions. Ablation threshold fluences were determined from a semi-logarithmic plot of the ablation crater diameter vs. laser fluence. The damage threshold fluence decreases for shorter pulse durations. In the investigated pulse duration range, the measured multi-pulse ablation threshold fluences are practically similar to those of undoped glass material (~1 Jcm-2). That means that the multi-pulse ablation threshold is independent on the doping level of the filters. For more than 100 pulses per spot and all pulse durations applied, the threshold fluence saturates. This leads to technically relevant damage threshold values in the femtosecond laser pulse duration domain. T2 - 4th SPIE's International Conference on High-Power Laser Ablation CY - Taos, NM, USA DA - 2002-04-22 KW - Ablation KW - Damage KW - Eye protection KW - Femtosecond pulse laser KW - Incubation KW - Laser safety KW - Threshold fluence PY - 2002 SN - 0-8194-4524-X DO - https://doi.org/10.1117/12.482109 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series VL - 1 IS - 4760 SP - 398 EP - 405 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-1550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Baudach, Steffen A1 - Kautek, Wolfgang A1 - Krüger, Jörg A1 - Welsch, E. T1 - Femtosecond laser damage of a high reflecting mirror JF - Thin solid films N2 - Multiple pulse investigations of 130-fs Ti:sapphire laser-induced damage of a high reflecting mirror consisting of alternating ?/4-layers of Ta2O5 and SiO2 and a single 500-nm Ta2O5 film were performed. In both cases, fused silica served as the substrate. For a fixed number of 1000 laser pulses per spot, a decrease in the damage threshold fluence of the mirror by a factor of two was observed by changing the repetition rate from 10 Hz to 1 kHz. A single 500-nm Ta2O5 film shows higher damage resistance compared to the mirror. The mirror and the Ta2O5 film samples were partially coated with a 300-nm-thick aluminium layer. The aluminium coating does not influence the damage threshold of the dielectrics underneath. KW - Aluminium KW - Laser ablation KW - Optical coatings KW - Silicon oxide PY - 2002 DO - https://doi.org/10.1016/S0040-6090(02)00074-3 SN - 0040-6090 IS - 408 SP - 297 EP - 301 PB - Elsevier CY - Amsterdam AN - OPUS4-1382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bonse, Jörn A1 - Baudach, Steffen A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Exarhos, G. T1 - Femtosecond laser damage in dielectric coatings T2 - Laser-induced damage in optical materials - 2000 N2 - Multi-shot investigations of Ti:sapphire laser (wavelength (lambda) approximately equals 800 nm) induced damage were performed in three different laboratories (BAM, Berlin; LZH, Hannover; UNM, Albuquerque). The ablation behavior of a high reflecting mirror consisting of alternating (lambda) /4- layers of Ta2O5 and SiO2 was studied. Fused silica served as substrate. The influence of the pulse duration ((tau) equals 13 - 130 fs), the pulse number (30 - (infinity) ) and the repetition rate (10 Hz - 100 MHz) on the damage threshold will be discussed. T2 - 32nd Annual Boulder Damage Symposium CY - Boulder, CO, USA DA - 2000-10-16 PY - 2001 SN - 0-8194-4036-1 DO - https://doi.org/10.1117/12.425056 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 4347 SP - 24 EP - 34 PB - International Society for Optical Engineering (SPIE) CY - Bellingham, Wash. AN - OPUS4-6013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Baudach, Steffen A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, Matthias T1 - Femtosecond laser ablation of silicon-modification thresholds and morphology JF - Applied physics A N2 - We investigated the initial modification and ablation of crystalline silicon with single and multiple Ti:sapphire laser pulses of 5 to 400 fs duration. In accordance with earlier established models, we found the phenomena amorphization, melting, re-crystallization, nucleated vaporization, and ablation to occur with increasing laser fluence down to the shortest pulse durations. We noticed new morphological features (bubbles) as well as familiar ones (ripples, columns). A nearly constant ablation threshold fluence on the order of 0.2 J/cm2 for all pulse durations and multiple-pulse irradiation was observed. For a duration of ,100 fs, significant incubation can be observed, whereas for 5 fs pulses, the ablation threshold does not depend on the pulse number within the experimental error. For micromachining of silicon, a pulse duration of less than 500 fs is not advantageous. PY - 2002 DO - https://doi.org/10.1007/s003390100893 SN - 0947-8396 VL - 74 IS - 1 SP - 19 EP - 25 PB - Springer CY - Berlin AN - OPUS4-6328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Bachelier, G. A1 - Wiggins, S. M. A1 - Siegel, J. A1 - Solis, J. A1 - Krüger, Jörg A1 - Sturm, Heinz T1 - Femtosecond laser ablation of indium phosphide in air: dynamical, structural and morphological evolution JF - Journal of optoelectronics and advanced materials N2 - The irradiation of single-crystalline indium phosphide (c-InP) by Ti:sapphire femtosecond laser pulses (130 fs, 800 nm) in air is studied by means of in-situ time resolved reflectivity measurements [fs-time-resolved microscopy (100 fs-10 ns) and point probing analysis (ns - µs)] and by complementary ex-situ surface analytical methods (Micro Raman Spectroscopy, Scanning Force, and Optical Microscopy). The dynamics of melting, ablation, and optical breakdown as well as structural changes resulting from rapid solidification are investigated in detail. Different laser-induced surface morphologies are characterized and discussed on the basis of recent ablation and optical breakdown models. KW - Femtosecond laser ablation KW - Optical breakdown KW - Time-resolved measurements KW - Semiconductor KW - Indium phosphide PY - 2010 SN - 1454-4164 VL - 12 IS - 3 SP - 421 EP - 426 PB - INOE & INFM CY - Bucharest AN - OPUS4-21082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Femtosecond diffraction dynamics of laser-induced periodic surface structures on fused silica JF - Applied physics letters N2 - The formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration, 800?nm center wavelength) is studied experimentally using a transillumination femtosecond time-resolved (0.1 ps-1 ns) pump-probe diffraction approach. This allows to reveal the generation dynamics of near-wavelength-sized LIPSS showing a transient diffraction at specific spatial frequencies even before a corresponding permanent surface relief was observed. The results confirm that the ultrafast energy deposition to the materials surface plays a key role and triggers subsequent physical mechanisms such as carrier scattering into self-trapped excitons. KW - High-speed optical techniques KW - Laser beam effects KW - Silicon compounds KW - Surface structure PY - 2013 DO - https://doi.org/10.1063/1.4790284 SN - 0003-6951 SN - 1077-3118 VL - 102 IS - 5 SP - 054102-1 EP - 054102-4 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-27646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kautek, Wolfgang A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg T1 - Femtosecond and Nanosecond Pulse Laser Electrochemistry of Aluminium Alloys T2 - Electrochemistry in molecular and microscopic dimensions T2 - 53th Annual meeting of the International Society of Electrochemistry CY - Düsseldorf, Germany DA - 2002-09-15 PY - 2002 SP - 1(?) PB - DECHEMA CY - Frankfurt a.M. AN - OPUS4-1586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kautek, Wolfgang A1 - Daminelli-Widany, Grazia A1 - Meja, P. A1 - Cortona, Anna A1 - Krüger, Jörg A1 - Autric, M. ED - Phipps, C. R. T1 - Femtosecond and nanosecond laser removal of anodic oxide layers from aluminium T2 - High-power laser ablation IV T2 - 4th SPIE's International Conference on High-Power Laser Ablation CY - Taos, NM, USA DA - 2002-04-22 KW - Laser ablation KW - Laser spallation KW - Microphone KW - Acoustical measurement KW - Aluminium oxide PY - 2002 SN - 0-8194-4524-X SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 4760 SP - 239 EP - 246 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-1551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Birgit Angelika A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Krüger, Jörg T1 - Femtosecond and nanosecond laser decontaminations of biocidal-loaded wooden artworks JF - Applied Physics A N2 - Until the end of the 1980s many wooden artworks underwent surface treatment by liquid preservatives, e.g. Hylotox-59. DDT (dichlorodiphenyltrichloroethane) crystal structures are formed on the wooden surfaces by the "blooming" of chlorine compounds by time. In addition to an aesthetic disturbance, it is assumed that DDT represents a health risk. Therefore, the removal of DDT crystals from the surfaces is requested. Contaminated wood with natural biocide ageing, gilded and wood carved elements and wooden samples with paint layers were provided by the Schlossmuseum Sondershausen, Germany. Laser cleaning on selected surface areas on the objects was done by means of femtosecond and nanosecond laser pulses. For the same object, cleaning results using 30-fs laser pulses at 800 nm wavelength are compared to findings utilizing 10-ns laser pulses at 1064 nm wavelength. Before and after laser treatment, chlorine measurements at the same surface position were done by X-ray fluorescence analysis (XRF) as an indicator for the presence of DDT. In this way, pointwise chlorine depletion rates can be obtained for the different pulse duration regimes and wavelengths. Additionally, the object surfaces were examined using optical microscopy and multi spectral imaging analysis. T2 - EMRS Spring Meeting 2017, Symposium X “New frontiers in laser interaction: from hard coatings to smart materials" CY - Strasbourg, France DA - 22.05.2017 KW - Laser cleaning KW - Decontamination KW - Wood KW - DDT KW - Femtosecond laser PY - 2017 DO - https://doi.org/10.1007/s00339-017-1316-4 SN - 0947-8396 SN - 1432-0630 VL - 123 IS - 11 SP - Article 696, 1 EP - 9 PB - Springer AN - OPUS4-42564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Martin, Sven A1 - Mädebach, Heinrich A1 - Urech, L. A1 - Lippert, T. A1 - Wokaun, A. A1 - Kautek, Wolfgang T1 - Femto- and nanosecond laser treatment of doped polymethylmethacrylate JF - Applied surface science N2 - Femto- and nanosecond laser ablation of polymethylmethacrylate (PMMA) and PMMA doped with a linear absorber was investigated in the infrared spectral region. Ablation thresholds were determined and incubation phenomena were identified. The ‘degree’ of incubation was calculated employing a phenomenological model. The influence of the pulse duration on the machining quality of the polymers was examined. The presence of an absorbing chromophore is not a prerequisite for a controllable fs-laser structuring in contrast to the ns-treatment. Surface swelling always accompanied ablation. KW - Laser ablation KW - Laser beam machining KW - Doping thin films KW - Polymers-radiation effects PY - 2005 DO - https://doi.org/10.1016/j.apsusc.2005.01.078 SN - 0169-4332 SN - 1873-5584 VL - 247 SP - 406 EP - 411 PB - North-Holland CY - Amsterdam AN - OPUS4-7470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Martin, Sven A1 - Mädebach, Heinrich A1 - Kautek, Wolfgang A1 - Urech, L. A1 - Lippert, Th. A1 - Wokaun, A. T1 - Femto- and Nanosecond Laser Treatment of Doped Polymethylmethacrylate T2 - E-MRS 2004 Spring Meeting T2 - E-MRS 2004 Spring Meeting CY - Strasbourg, France DA - 2004-08-24 PY - 2004 AN - OPUS4-4145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heidmann, B. A1 - Andree, Stefan A1 - Levcenko, S. A1 - Unold, T. A1 - Abou-Ras, D. A1 - Schäfer, N. A1 - Bonse, Jörn A1 - Krüger, Jörg A1 - Schmid, M. T1 - Fabrication of regularly arranged chalcopyrite micro solar cells via femtosecond laser-induced forward transfer for concentrator application JF - ACS Applied Energy Materials N2 - A laser-based bottom-up technique for the fabrication of Cu(In,Ga)Se2 (CIGSe) micro solar cells is presented. We use femtosecond laser-induced forward transfer (LIFT) to transport a metallic precursor composed of copper, indium, and gallium onto a molybdenum back contact layer on a glass substrate. A CIGSe absorber forms by subsequent selenization. An array of micro absorbers with defined spacing is fabricated to solar cells and characterized under concentrated light illumination. The solar cell array exhibited a conversion efficiency of 1.4‰ at 1 sun as well as a significant efficiency enhancement of 68% rel. under 20-fold concentration. This work demonstrates the possibility of directly grown micrometer-sized solar cells based on chalcogenide absorber layers, enabling effective material usage. KW - Micro solar cells KW - Light concentration KW - LIFT KW - Chalcopyrite KW - Femtosecond laser PY - 2018 DO - https://doi.org/10.1021/acsaem.7b00028 SN - 2574-0962 VL - 1 IS - 1 SP - 27 EP - 31 PB - ACS CY - Washington, DC AN - OPUS4-43999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Caricato, A.P. A1 - Focsa, C. A1 - Krüger, Jörg A1 - Palla Papavlu, A. T1 - European materials research society spring meeting 2016 symposium "Laser - materials interactions for tailoring future's applications" Preface JF - Applied Surface Science N2 - This Conference Proceedings volume contains a selection of the contributions presented in Symposium C “Laser-material interactions for tailoring future applications” organized during the annual Spring Meeting of the European Materials Research Society (E-MRS) held from May 2nd to 6th 2016 in the Lille Grand Palais, France. T2 - EMRS Spring Meeting 2016, Symposium "“Laser-material interactions for tailoring future applications” CY - Lille, France DA - 02.05.2016 KW - European Materials Research Society (E-MRS) KW - Laser-material interactions KW - Spring Meeting 2016 PY - 2017 DO - https://doi.org/10.1016/j.apsusc.2017.04.089 SN - 0169-4332 SN - 1873-5584 VL - 418 IS - Part B SP - 419 EP - 419 PB - Elsevier B.V. AN - OPUS4-40570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Legall, Herbert A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - Emission of X-rays during ultrashort pulse laser processing T2 - Proceedings Lasers in Manufacturing Conference 2021 N2 - Ultrashort pulse laser materials processing can be accompanied by the production of X-rays. Small doses per laser pulse can accumulate to significant dose rates at high laser pulse repetition rates which may exceed the permitted X-ray limits for human exposure. Consequently, a proper radiation shielding must be considered in laser machining. A brief overview of the current state of the art in the field of undesired generation of X-ray radiation during ultrashort pulse laser material processing in air is presented. T2 - Lasers in Manufacturing Conference 2021 CY - Online meeting DA - 21.06.2021 KW - Ultra-short pulse laser processing KW - Laser-induced X-ray emission KW - Radiation protection PY - 2021 SP - 1 EP - 5 AN - OPUS4-53866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Legall, Herbert A1 - Bonse, Jörn T1 - Emission of X-rays during ultrashort pulse laser processing N2 - Ultrashort laser pulses have found their way into industrial material processing. They take advantage of the fact that moderate laser fluences can produce high quality material removal without significant thermal influence. The growing availability of powerful, highly repeating laser sources and an advanced laser beam control have favored these developments. However, the laser-matter interaction can be accompanied by the production of X-rays. Small doses per laser pulse can accumulate to significant dose rates at high laser pulse repetition rates which may exceed the permitted X-ray limits for human exposure. Consequently, a proper radiation shielding must be considered in laser material processing. The paper summarizes the current state of the art in the field of undesired generation of X-ray radiation during ultrashort pulse laser material processing in air. T2 - LiM - Lasers in Manufacturing 2021 CY - Online meeting DA - 21.06.2021 KW - Ultrashort laser pulses KW - Material processing KW - X-ray emission KW - Radiation protection PY - 2021 AN - OPUS4-52865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Einführung Ultrakurzpulslaser N2 - Der Vortrag gibt eine Einführung zu ultrakurzen Laserpulsen, der Ultrakurzpulslaser-Materialbearbeitung und dem Schutz gegenüber unerwünschter Röntgenstrahlung bei der Ultrakurzpulslaser-Materialbearbeitung. T2 - Vorkommnisse in der Medizin und Ultrakurzpulslaser, Veranstaltungsreihe: Erfahrungsaustausch zu Themen des Vollzugs im Strahlenschutz CY - Cologne, Germany DA - 26.04.2023 KW - Ultrakurze Laserpulse KW - Materialbearbeitung KW - Röntgenstrahlung KW - Strahlenschutz KW - Abschirmung PY - 2023 AN - OPUS4-57408 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cubero, A. A1 - Martínez, E. A1 - Angurel, L.A. A1 - de la Fuente, G.F. A1 - Navarro, R. A1 - Legall, Herbert A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Effects of laser-induced periodic surface structures on the superconducting properties of Niobium JF - Applied surface science N2 - It is well known that the use of ultrashort (fs) pulsed lasers can induce the generation of (quasi-) periodic nanostructures (LIPSS, ripples) on the surface of many materials. Such nanostructures have also been observed in sample’s surfaces irradiated with UV lasers with a pulse duration of 300 ps. In this work, we compare the characteristics of these nanostructures on 1-mm and on 25-μm thick niobium sheets induced by 30 fs n-IR and 300 ps UV pulsed lasers. In addition to conventional continuous or burst mode processing configurations, two-dimensional laser beam and line scanning modes have been investigated in this work. The latter allows the processing of large areas with a more uniform distribution of nanostructures at the surface. The influence of the generated nanostructures on the superconducting properties of niobium has also been explored. For this aim, magnetic hysteresis loops have been measured at different cryogenic temperatures to analyse how these laser treatments affect the flux pinning behaviour and, in consequence, the superconductor’s critical current values. It was observed that laser treatments are able to modify the superconducting properties of niobium samples. T2 - E-MRS Spring Meeting 2019 CY - Nice, France DA - 27.05.2019 KW - Superconductivity KW - Laser-induced periodic surface structures (LIPSS) KW - Niobium PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502541 DO - https://doi.org/10.1016/j.apsusc.2019.145140 SN - 0169-4332 SN - 1873-5584 VL - 508 IS - 1 SP - 145140-1 EP - 145140-7 PB - Elsevier CY - Amsterdam AN - OPUS4-50254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brockmann, N. A1 - Sicken, A. A1 - Krüger, Jörg T1 - Effects of laser cleaning on the condition of different silk model samples using varying wavelengths and pulse durations JF - Heritage Science N2 - The cleaning of aged silk fibers poses a common challenge in the conservation of textiles, since traditional cleaning techniques often yield unsatisfactory results or even harm objects. In this regard, cleaning objects with laser radiation is a promising addition to the range of available methods. Due to it being contactless, even brittle and touch-sensitive objects with disfiguring or harmful soiling could potentially be cleaned and therefore made accessible for research and presentation. Examples of treatment have sometimes shown spectacular results. Still there is some skepticism concerning the safety of this treatment for textile materials, which has been strengthened through previous 532 nm wavelength nanosecond laser cleaning studies on silk fibers. Taking these published results into account, the range of examined laser parameters has been extended in this study, from 532 nm nanosecond laser to 1064 nm nanosecond and even 800 nm femtosecond laser, reevaluating the effect of this treatment on the fibers. The physicochemical processes taking place on the silk fibers when cleaning with lasers are complex and still not fully understood. The aim of this project was therefore to bring more clarification about potential effects of those processes on the condition of silk samples treated with a set of different parameters for wavelength, pulse duration, energy density and number of pulses per spot. It also looks at the influence of the presence of soiling on the results. The analysis of potential effects was then carried out using statistical methods and advanced analytics. Scanning electron microscopy, Fourier-transform infrared spectroscopy and colorimetry technology provided the required insights to better assess the effects. Results show that laser cleaning of silk fibers, like most other conventional cleaning techniques, is not completely without risk, but knowing what the possible effects are helps making decisions on whether the benefits of the technique used justify these risks. KW - Laser cleaning KW - Cultural heritage KW - Conservation KW - Silk PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594601 DO - https://doi.org/10.1186/s40494-024-01152-1 SN - 2050-7445 VL - 12 IS - 1 SP - 1 EP - 15 PB - Springer AN - OPUS4-59460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Editorial: Special Issue “Advanced Pulse Laser Machining Technology" JF - Materials N2 - “Advanced Pulse Laser Machining Technology” is a rapidly growing field that can be tailored to special industrial and scientific applications. This is significantly driven by the availability of high-repetition-rate laser sources and novel beam delivery concepts. KW - Editorial KW - Pulse Laser KW - Laser Machining KW - Ultrashort laser pulses PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568410 DO - https://doi.org/10.3390/ma16020819 SN - 1996-1944 VL - 16 IS - 2 SP - 1 EP - 4 PB - MDPI CY - Basel AN - OPUS4-56841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Rosenfeld, A. A1 - Höhm, S. A1 - Krüger, Jörg A1 - Bonse, Jörn ED - Reedijk, J. T1 - Dynamics of ultrashort double-pulse laser ablation of solid surfaces T2 - Reference Module in Chemistry, Molecular Sciences and Chemical Engineering, Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry N2 - Given their unique properties, ultrashort laser pulses with durations in the femtosecond to picosecond range currently open new avenues in the field of laser materials processing, resulting in groundbreaking new applications based on laser-induced surface functionalization. This article reviews the usability of temporally distributed energy deposition via double-pulse irradiation in applications based on laser ablation. This includes simple new techniques for surface nanostructuring and improved sensitivities in spectroscopic material analyses. KW - Carrier excitation KW - Double-pulse KW - Interferometer KW - Laser ablation KW - Femtosecond PY - 2017 UR - https://www.sciencedirect.com/science/article/pii/B9780124095472141277 SN - 978-0-12-409547-2 DO - https://doi.org/10.1016/B978-0-12-409547-2.14127-7 SP - 1 EP - 10 PB - Elsevier AN - OPUS4-43594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Rohloff, M. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Dynamics of the formation of laser-induced periodic surface structures on dielectrics and semiconductors upon femtosecond laser pulse irradiation sequences JF - Applied physics A N2 - The formation of laser-induced periodic surface structures (LIPSS) upon irradiation of fused silica and silicon with multiple (NDPS) irradiation sequences consisting of linearly polarized femtosecond laser pulse pairs (pulse duration ~150 fs, central wavelength ~800 nm) is studied experimentally. Nearly equal-energy double-pulse sequences are generated allowing the temporal pulse delay Δt between the cross-polarized individual fs-laser pulses to be varied from -40 ps to +40 ps with a resolution of ~0.2 ps. The surface morphologies of the irradiated surface areas are characterized by means of scanning electron and scanning force microscopy. Particularly for dielectrics in the sub-ps delay range striking differences in the orientation and spatial characteristics of the LIPSS can be observed. For fused silica, a significant decrease of the LIPSS spatial periods from ~790 nm towards ~550 nm is demonstrated for delay changes of less than ~2 ps. In contrast, for silicon under similar irradiation conditions, the LIPSS periods remain constant (~760 nm) for delays up to 40 ps. The results prove the impact of laser-induced electrons in the conduction band of the solid and associated transient changes of the optical properties on fs-LIPSS formation. PY - 2013 DO - https://doi.org/10.1007/s00339-012-7184-z SN - 0947-8396 VL - 110 IS - 3 SP - 553 EP - 557 PB - Springer CY - Berlin AN - OPUS4-27787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Herzlieb, M. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Dynamics of the formation of laser-induced periodic surface structures (LIPSS) upon femtosecond two-color double-pulse irradiation of metals, semiconductors, and dielectrics JF - Applied Surface Science N2 - In order to address the dynamics and physical mechanisms of LIPSS formation for three different classes of materials (metals, semiconductors, and dielectrics), two-color double-fs-pulse experiments were performed on Titanium, Silicon and Fused Silica. For that purpose a Mach–Zehnder interferometer generated polarization controlled (parallel or cross-polarized) double-pulse sequences at 400 nm and 800 nm wavelength, with inter-pulse delays up to a few picoseconds. Multiple of these two-color double-pulse sequences were collinearly focused by a spherical mirror to the sample surfaces. The fluence of each individual pulse (400 nm and 800 nm) was always kept below its respective ablation threshold and only the joint action of both pulses lead to the formation of LIPSS. Their resulting characteristics (periods, areas) were analyzed by scanning electron microscopy. The periods along with the LIPSS orientation allow a clear identification of the pulse which dominates the energy coupling to the material. For strong absorbing materials (Silicon, Titanium), a wavelength-dependent plasmonic mechanism can explain the delay-dependence of the LIPSS. In contrast, for dielectrics (Fused Silica) the first pulse always dominates the energy deposition and LIPSS orientation, supporting a non-plasmonic formation scenario. For all materials, these two-color experiments confirm the importance of the ultrafast energy deposition stage for LIPSS formation. KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Laser-induced periodic surface structures (LIPSS) KW - Mach-Zehnder interferometer KW - Ultrafast optical techniques PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0169433215031347 DO - https://doi.org/10.1016/j.apsusc.2015.12.129 SN - 0169-4332 SN - 1873-5584 VL - 374 SP - 331 EP - 338 PB - Elsevier CY - Amsterdam, Netherlands AN - OPUS4-35938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - von Lerber, K. T1 - Determination of a working range for the laser cleaning of soiled silk T2 - Konferenz LACONA VI, Lasers in the Conservation of Artworks T2 - Konferenz LACONA VI, Lasers in the Conservation of Artworks CY - Vienna, Austria DA - 2005-09-21 PY - 2005 AN - OPUS4-7135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Lerber, K. von ED - Johann Nimmrichter, ED - Kautek, Wolfgang ED - Manfred Schreiner, T1 - Determination of a working range for the laser cleaning of soiled silk T2 - LACONA VI - Lasers in the conservation of artworks (Proceedings) T2 - LACONA VI CY - Vienna, Austria DA - 2005-09-21 KW - Laser KW - Cleaning KW - Silk KW - Textiles PY - 2007 SN - 978-3-540-72129-1 SN - 0930-8989 N1 - Serientitel: Springer proceedings in physics – Series title: Springer proceedings in physics IS - 116 SP - 321 EP - 327 PB - Springer CY - Berlin AN - OPUS4-16380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Schmidt, Birgit A1 - Koch, W. A1 - Pentzien, Simone A1 - Krüger, Jörg ED - Gabsch, T. T1 - Der Einsatz von Lasertechnik an Modellsystemen zentralasiatischer Wandmalereifragmente T2 - Auf Grünwedels Spuren: Restaurierung und Forschung an zentralasiatischen Wandmalereien KW - Laserreinigung KW - Wandmalerei KW - Verrußung KW - Kunststoffschicht KW - Probekörper PY - 2012 SN - 978-3-7338-0385-8 IS - Kap. 10 SP - 152 EP - 157 PB - Koehler & Amelang GmbH AN - OPUS4-26178 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Birgit Angelika A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Krüger, Jörg A1 - Roth, C. A1 - Beier, O. A1 - Hartmann, A. A1 - Grünler, B. T1 - Decontamination of biocidal loaded wooden artworks by means of laser and plasma processing T2 - Proceedings of the International Conference LACONA XI N2 - Many wooden artworks are contaminated by DDT (dichlorodiphenyltrichloroethane) as a result of a surface treatment by means of the liquid preservative Hylotox-59©. It was used until the end of the 1980s. DDT crystal structures are formed on the wood surfaces by the "blooming" of chlorine compounds. In addition to an aesthetic disturbance, it is assumed that DDT represents a health risk. Even decades after applying, the toxins in the wood preservatives are still detectable because they are of low volatility in many wood samples. Contaminated waste wood with natural biocide ageing, gilded and wood carved elements of an old picture frame and wooden samples with paint layers were provided by the Schlossmuseum Sondershausen. Non-contact procedures using laser and plasma appear reasonable to remove the DDT crystals. During the experiments, health and safety issues for the operator have to be taken into account. The removal of DDT was evaluated employing femtosecond and nanosecond laser radiation and cold atmospheric plasma techniques with different working gases (air, nitrogen, and argon). Before laser application, a chlorine measurement representing the DDT density on the wooden surface is done by X-ray fluorescence (XRF) analysis as reference. After laser processing, the XRF analysis is used again at the same surface position to determine the depletion rate. Additionally, a documentation and characterization of the sample surface is performed before and after laser and plasma treatment using optical microscopy (OM). For plasma processing with various systems a chlorine measurement is done by gas chromatographic-mass spectrometry (GCMS) analysis. T2 - 11th Conference on Lasers in the Conservation of Artworks CY - Kraków, Poland DA - 20.09.2016 KW - Decontamination KW - DDT KW - Wooden artworks KW - Femtosecond laser KW - Cold atmospheric pressure plasma PY - 2017 SN - 978-83-231-3875-4 DO - https://doi.org/10.12775/3875-4.17 SP - 241 EP - 251 PB - NCU Press CY - Toruń AN - OPUS4-43526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Schmidt, Birgit A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Decontamination of biocidal loaded wooden artworks using femtosecond and nanosecond laser processing N2 - Until the end of the 1980s many wooden artworks underwent surface treatment by liquid preservatives, e.g. Hylotox-59. As a result, DDT (dichlorodiphenyltrichloroethane) crystal structures are formed on the wood surfaces by the "blooming" of chlorine compounds. In addition to an aesthetic disturbance, it is assumed that DDT represents a health risk. Even decades after applying, the toxins in the wood preservatives are still detectable. Contaminated waste wood with natural biocide ageing, gilded and wood carved elements of an old picture frame and wooden samples with paint layers were provided by the Schlossmuseum Sondershausen, Germany. Laser cleaning of areas of some square millimeters on the surfaces of the objects was done by means of femtosecond and nanosecond laser pulses. For 30-fs laser pulses at 800 nm wavelength a line-wise meandering movement of the object under the focused beam was performed. 10-ns laser pulses at 1064 nm and 7-ns laser pulses at 532 nm wavelength were applied to the sample surface using a scanner. Before laser application, a chlorine measurement was done by X-ray fluorescence analysis (XRF) as reference. After laser processing, the XRF analysis was used again at the same surface position to determine chlorine depletion rates of up to 75% (30 fs, 800 nm), 70% (10 ns, 1064 nm), and 22% (7 ns, 532 nm). For the application of 30-fs laser pulses on waste wood, no crystalline DDT residues remain on the sample surface observed utilizing optical microscopy. T2 - European Materials Research Society (EMRS) Spring Meeting 2017, Symposium X “New frontiers in laser interaction: from hard coatings to smart materials” CY - Strasbourg, France DA - 22.05.2017 KW - Femtosecond laser KW - Nanosecond laser KW - Laser cleaning KW - DDT KW - Wooden artworks PY - 2017 AN - OPUS4-40410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Damage of optical materials as a limit for the application of ultrashort laser pulses T2 - International Conference Advanced Laser Technology (ALT´08) T2 - International Conference Advanced Laser Technology (ALT´08) CY - Siófok, Hungary DA - 2008-09-13 PY - 2008 AN - OPUS4-17532 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Solis, J. A1 - Spielmann, C. A1 - Lippert, T. A1 - Krüger, Jörg T1 - Damage mechanisms in polymers upon NIR femtosecond pulse laser irradiation: sub-threshold processes and their implications for laser safety applications T2 - AIP Conference Proceedings 1278 N2 - This contribution investigates laser-induced damage of thin film and bulk polymer samples, with the focus on physical processes occurring close to the damage threshold. In-situ real-time reflectivity (RTR) measurements with picosecond (ps) and nanosecond (ns) temporal resolution were performed on thin polymer films on a timescale up to a few microseconds (µs). A model for polymer thin film damage is presented, indicating that irreversible chemical modification processes take place already below the fluence threshold for macroscopic damage. On dye-doped bulk polymer filters (as used for laser goggles), transmission studies using fs-and ps-laser pulses reveal the optical saturation behavior of the material and its relation to the threshold of permanent damage. Implications of the sub-threshold processes for laser safety applications will be discussed for thin film and bulk polymer damage. T2 - International high-power laser ablation conference CY - Santa Fe, USA DA - 2010-04-18 KW - Polymer KW - Laser damage KW - Ultrashort laser pulses KW - Time-resolved reflectivity measurements KW - Laser safety PY - 2010 UR - http://link.aip.org/link/?APCPCS/1278/56/1 SN - 978-0-7354-0828-9 DO - https://doi.org/10.1063/1.3507148 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1278 SP - 56 EP - 64 PB - American Institute of Physics CY - Melville, NY, USA AN - OPUS4-22156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Mezera, Marek A1 - Florian, C. A1 - Römer, G.-W. A1 - Krüger, Jörg A1 - Bonse, Jörn ED - Stoian, R. ED - Bonse, Jörn T1 - Creation of Material Functions by Nanostructuring T2 - Ultrafast Laser Nanostructuring — The Pursuit of Extreme Scales N2 - Surface nanostructures provide the possibility to create and tailor surface functionalities mainly via controlling their topography along with other chemical and physical material properties. One of the most appealing technologies for surface functionalization via micro- and nanostructuring is based on laser processing. This can be done either via direct contour-shaping of the irradiated material using a tightly focused laser beam or in a self-ordered way that allows employing larger laser beam diameters along with areal scanning to create a variety of laser-induced periodic surface structures (LIPSS). For the latter approach, particularly ultrashort pulsed lasers have recently pushed the borders across long-lasting limitations regarding the minimum achievable feature sizes and additionally boosted up the production times. This chapter reviews the plethora of recently investigated applications of LIPSS—for example, via imposing diffractive or plasmonic structural colors, the management of liquids and surface wetting properties, biomedical and bioinspired functionalities, beneficial effects in tribology for reducing friction and wear, the manipulation of optical scattering and absorption in photovoltaics, or the modification of magnetic or superconducting surface properties in other energy applications. The footprint of the LIPSS-based technology is explored in detail regarding the current state of industrialization, including an analysis of the market and associated LIPSS production costs. KW - Laser-induced periodic surface structures, LIPSS KW - Surface functionalization KW - Nanostructures KW - Microstructures KW - Laser processing PY - 2023 SN - 978-3-031-14751-7 SN - 978-3-031-14752-4 DO - https://doi.org/10.1007/978-3-031-14752-4_23 VL - 239 SP - 827 EP - 886 PB - Springer Nature Switzerland AG CY - Cham, Switzerland AN - OPUS4-57295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Symietz, Christian A1 - Gildenhaar, Renate A1 - Berger, Georg T1 - Covering Ti6Al4V implant material with bioactive ceramics using femtosecond laser processing T2 - 5th European Conference on Applications of Femtosecond Lasers in Materials Science (FemtoMat 2013) T2 - 5th European Conference on Applications of Femtosecond Lasers in Materials Science (FemtoMat 2013) CY - Mauterndorf, Austria DA - 2013-03-18 PY - 2013 AN - OPUS4-28048 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Koter, Robert T1 - Cleaning of soiled paper model samples using short and ultrashort laser pulses T2 - Konferenz "New Approaches to Book and Paper Conservation-Restoration" T2 - Konferenz "New Approaches to Book and Paper Conservation-Restoration" CY - Horn, Austria DA - 2011-05-09 PY - 2011 AN - OPUS4-21839 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Koter, Robert A1 - Krüger, Jörg ED - Engel, P. ED - Schirò, J. ED - Larsen, R. ED - Moussakova, E. ED - Kecskeméti, I. T1 - Cleaning of soiled paper model samples using short and ultrashort laser pulses T2 - Conference 'New Approaches to Book and Paper Conservation - Restoration' (Proceedings) N2 - Paper is one of the most important materials representing and witnessing human culture particularly as a carrier medium for text and image. As soiling hampers the reception of information, paper cleaning techniques are needed. Traditional mechanical and chemical cleaning methods are used by conservator-restorers. In some cases, a classical cleaning procedure of paper objects yields unsatisfactory results or a conventional treatment is even impossible. Especially, fragile paper objects cause problems due to mechanical instabilities. Laser cleaning as a non-contact method might be a way to overcome some of the limitations of classical cleaning techniques. Laser parameters have to be chosen to achieve removal of the soiling without influencing the artwork. Any immediate as well as long-term effects causing an irreversible change of the artwork have to be avoided. At present, most laser applications are found in stone and metal conservation, while laser treatment of complex organic materials like paper is still not fully developed for application in conservators' workshops. This contribution describes recent work of pulsed laser cleaning of soiled model samples. Pure cellulose, rag paper and wood-pulp paper were mechanically soiled with pulverized charcoal in a standardized procedure to make model samples representing essential characteristics of contaminated real-world artworks. Afterwards, model samples were cleaned using short and ultrashort laser pulses in the nanosecond and femtosecond time domain, respectively. An extensive analysis of the model samples after laser treatment using an optical microscope and a multi-spectral imaging system allows a comparison of the cleaning results obtained with both laser sources. T2 - Conference 'New Approaches to Book and Paper Conservation - Restoration' CY - Horn, Austria DA - 09.05.2011 KW - Laser cleaning KW - Ablation KW - Laser impact on surfaces KW - Paper KW - Femtosecond laser KW - Nanosecond laser PY - 2011 SN - 978-3-85028-518-6 SP - 519 EP - 532 PB - Verlag Berger, Horn CY - Vienna, Austria AN - OPUS4-23705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotsifaki, D.G. A1 - Zekou, L. A1 - Pentzien, Simone A1 - Krüger, Jörg A1 - Serafetinides, A.A. ED - Saunders, D. ED - Strlic, M. ED - Korenberg, C. ED - Luxford, N. ED - Birkhölzer, K. T1 - Cleaning of artificially soiled papers by infrared and mid-infrared lasers T2 - LACONA IX - Lasers in the conservation of artworks (Proceedings) N2 - One of the most important materials presenting and witnessing human culture is paper. The cleaning of paper is often necessary because contamination must be removed so that the fragile organic substrate can be preserved. The conventional cleaning methods are mechanical or involve the application of chemicals. These methods can damage drawings or print layers to some extent or make the original paper substrate brittle. More specifically, the use of a scalpel blade can cause damage to fibers. Chemical cleaning is difficult to perform locally, can dissolve foreign matter that then migrates into the paper substrate, or involves volatile organic compounds that can be harmful to the conservator. There is, therefore, a need for new conservation technologies aimed at the safe cleaning of paper. Lasers have proved to be an appropriate tool for cleaning as the energy dose and penetration depth at the specific point of contamination can be controlled. Additionally, if used properly, laser cleaning is not destructive to the paper. T2 - LACONA IX - Lasers in the conservation of artworks CY - London, UK DA - 07.09.2011 KW - Laser cleaning KW - Paper KW - Artificial soiling KW - Nanosecond laser KW - Microsecond laser PY - 2013 SN - 978-1-904982-87-6 SP - 219 EP - 221 PB - Archetype publications Ltd. AN - OPUS4-27956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artificially soiled paper with 532-nm nanosecond laser radiation T2 - EMRS 2007 Spring Meeting, Symposium S: Science & Technology of Cultural heritage Materials : Art conservation and Restoration T2 - EMRS 2007 Spring Meeting, Symposium S: Science & Technology of Cultural heritage Materials : Art conservation and Restoration CY - Strasbourg, France DA - 2007-05-28 PY - 2007 AN - OPUS4-14763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artificially soiled paper with 532-nm nanosecond laser radiation JF - Applied physics A N2 - Cleaning of paper is a challenging task due to the fact that a contamination should be removed and a fragile organic original material has to be preserved. Pulsed laser cleaning of artificially soiled Whatman© filter paper samples serving as models for historical paper was performed. Different cleaning strategies employing 8-ns laser pulses at 532 nm wavelength were applied to clean paper avoiding undesired effects like discoloration (yellowing) and mechanical deterioration of the substrate. Multi shot experiments with low-energy pulses were compared with single pulse investigations utilizing high pulse energies achieving a constant energy load incident on the samples in both cases. The cleaning efficiency and possible yellowing effects were evaluated by means of a multi spectral imaging system. An extensive microscopic analysis of the cleaned parts of the samples provided insight into the remaining soiling on the surface and in the bulk of the paper material after laser treatment. As a reference, a hard and a soft eraser were used to clean the samples. KW - Laser cleaning KW - Paper KW - Colorimetry PY - 2008 DO - https://doi.org/10.1007/s00339-008-4476-4 SN - 0947-8396 VL - 92 IS - 1 SP - 179 EP - 183 PB - Springer CY - Berlin AN - OPUS4-17331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Koter, Robert A1 - Krüger, Jörg T1 - Cleaning of artificially soiled paper using nanosecond, picosecond and femtosecond laser pulses JF - Applied physics A N2 - Cleaning of cultural assets, especially fragile organic materials like paper, is a part of the conservation process. Laser radiation as a non-contact tool offers prospects for that purpose. For the studies presented here, paper model samples were prepared using three different paper types (pure cellulose, rag paper, and wood-pulp paper). Pure cellulose serves as reference material. Rag and woodpulp paper represent essential characteristics of the basic materials of real-world artworks. The papers were mechanically soiled employing pulverized charcoal. Pure and artificially soiled paper samples were treated with laser pulses of 28 fs (800 nm wavelength) and 8–12 ns (532 nm) duration in a multi pulse approach. Additionally, the cellulose reference material was processed with 30 ps (532 nm) laser pulses. Damage and cleaning thresholds of pure and soiled paper were determined for the different laser regimes. Laser working ranges allowing for removal of contamination and avoiding permanent modification to the substrate were found. The specimens prior and after laser illumination were characterized by light-optical microscopy (OM) and scanning electron microscopy (SEM) as well as multi spectral imaging analysis. The work extends previous nanosecond laser cleaning investigations on paper into the ultra-short pulse duration domain. KW - Laser cleaning KW - Ablation KW - Laser impact on surfaces KW - Paper KW - Femtosecond laser PY - 2010 DO - https://doi.org/10.1007/s00339-010-5809-7 SN - 0947-8396 VL - 101 IS - 2 SP - 441 EP - 446 PB - Springer CY - Berlin AN - OPUS4-22155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Pentzien, Simone A1 - Conradi, Andrea T1 - Cleaning of artifically soled paper using nanosecond, picosecond and femtosecond laser pulses T2 - Konferenz COLA 09 (10th International Conference on Laser Ablation) T2 - Konferenz COLA 09 (10th International Conference on Laser Ablation) CY - Singapore DA - 2009-11-22 PY - 2009 AN - OPUS4-19762 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Florian, Camilo A1 - Wonneberger, R. A1 - Undisz, A. A1 - Kirner, Sabrina V. A1 - Wasmuth, Karsten A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Chemical effects during the formation of various types of femtosecond laser-generated surface structures on titanium alloy JF - Applied Physics A N2 - In this contribution, chemical, structural, and mechanical alterations in various types of femtosecond laser-generated surface structures, i.e., laser-induced periodic surface structures (LIPSS, ripples), Grooves, and Spikes on titanium alloy, are characterized by various surface analytical techniques, including X-ray diffraction and glow-discharge optical emission spectroscopy. The formation of oxide layers of the different laser-based structures inherently influences the friction and wear performance as demonstrated in oil-lubricated reciprocating sliding tribological tests (RSTTs) along with subsequent elemental mapping by energy-dispersive X-ray analysis. It is revealed that the fs-laser scan processing (790 nm, 30 fs, 1 kHz) of near-wavelength-sized LIPSS leads to the formation of a graded oxide layer extending a few hundreds of nanometers into depth, consisting mainly of amorphous oxides. Other superficial fs-laser-generated structures such as periodic Grooves and irregular Spikes produced at higher fluences and effective number of pulses per unit area present even thicker graded oxide layers that are also suitable for friction reduction and wear resistance. Ultimately, these femtosecond laser-induced nanostructured surface layers efficiently prevent a direct metal-to-metal contact in the RSTT and may act as an anchor layer for specific wear-reducing additives contained in the used engine oil. KW - Laser-induced oxide layer KW - Laser-induced periodic surface strctures (LIPSS) KW - Femtosecond laser processing KW - Tribology KW - Surface processing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505660 DO - https://doi.org/10.1007/s00339-020-3434-7 SN - 0947-8396 SN - 1432-0630 VL - 126 IS - 4 SP - 266 PB - Springer Nature Switzerland AG AN - OPUS4-50566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Kai A1 - Mirabella, Francesca A1 - Knigge, Xenia A1 - Mezera, Marek A1 - Weise, Matthias A1 - Sahre, Mario A1 - Wasmuth, Karsten A1 - Voss, Heike A1 - Hertwig, Andreas A1 - Krüger, Jörg A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Chemical and topographical changes upon sub-100-nm laser-induced periodic surface structure formation on titanium alloy: the influence of laser pulse repetition rate and number of over-scans JF - Physica Status Solidi A N2 - Titanium and its alloys are known to allow the straightforward laser-based manufacturing of ordered surface nanostructures, so-called high spatial frequency laser-induced periodic surface structures (HSFL). These structures exhibit sub-100 nm spatial periods – far below the optical diffraction limit. The resulting surface functionalities are usually enabled by both, topographic and chemical alterations of the nanostructured surfaces. For exploring these effects, multi-method characterizations were performed here for HSFL processed on Ti–6Al–4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm, ≈1 ps pulse duration, 1–400 kHz) under different laser scan processing conditions, i.e., by systematically varying the pulse repetition frequency and the number of laser irradiation passes. The sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), tactile stylus profilometry, as well as near-surface chemical analyses hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (ToF-SIMS). This provides a quantification of the laser ablation depth, the geometrical HSFL characteristics and enables new insights into the depth extent and the nature of the non-ablative laser-induced near-surface oxidation accompanying these nanostructures. This allows to answer the questions how the processing of HSFL can be industrially scaled up, and whether the latter is limited by heat-accumulation effects. T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics" CY - Strasbourg, France DA - 29.05.2023 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Laser processing KW - Hard X-ray photoelectron spectroscopy (HAXPES) KW - Time-of-flight secondary ion mass spectrometry (ToF-SIMS) PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589902 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/pssa.202300719 DO - https://doi.org/10.1002/pssa.202300719 SN - 1862-6319 VL - 220 SP - 1 EP - 12 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-58990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurster, R. A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Krüger, Jörg T1 - Characterization of laser-generated microparticles by means of a dust monitor and SEM imaging JF - Laser chemistry N2 - Nanosecond laser (1064 nm wavelength) cleaning of artificially soiled paper as a model sample simulating a real-world artwork was performed. During the cleaning process, the ejection of particles was monitored in situ by means of a dust monitor (8 size classes, ranging from 0.3 µm to >2 µm) and ex situ using a mini-cascade impactor (MKI, 5 stages). The cleaning result was analyzed by scanning electron microscopy (SEM) considering possible laser-induced damages to the substrate. Size distributions of emitted particles were measured depending on the processing parameters: laser fluence, F, and pulse number per spot, N. High numbers of large (>2 µm) particles were collected by the mini-cascade impactor indicating a gas dynamical liftoff process. Obviously, these particles were not affected by the laser-matter interaction. The different methods (SEM, MKI, and dust monitor) are compared with respect to their usefulness for a proper interpretation of the cleaning results. PY - 2006 DO - https://doi.org/10.1155/2006/31862 SN - 0278-6273 SN - 1476-3516 VL - 2006 IS - Article ID 31862 SP - 1 EP - 5(?) PB - Harwood Academic Publ. CY - London AN - OPUS4-14467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pentzien, Simone A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Krüger, Jörg A1 - Kleber, F. A1 - Hollaus, F. A1 - Diem, M. A1 - Sablatnig, R. ED - Park, J.-I. ED - Kim, J. T1 - Can Modern Technologies Defeat Nazi Censorship? T2 - ACCV 2012 Workshops, 11th Asian conference on computer vision N2 - Censorship of parts of written text was and is a common practice in totalitarian regimes. It is used to destroy information not approved by the political power. Recovering the censored text is of interest for historical studies of the text. This paper raises the question, whether a censored postcard from 1942 can be made legible by applying multispectral imaging in combination with laser cleaning. In the fields of art conservation (e.g. color measurements), investigation (e.g. Analysis of underdrawings in paintings), and historical document analysis, multispectral imaging techniques have been applied successfully to give visibility to information hidden to the human eye. The basic principle of laser cleaning is to transfer laser pulse energy to a contamination layer by an absorption process that leads to heating and evaporation of the layer. Partial laser cleaning of postcards is possible; dirt on the surface can be removed and the obscured pictures and writings made visible again. We applied both techniques to the postcard. The text could not be restored since the original ink seems to have suffered severe chemical damage. T2 - ACCV 2012 Workshops, 11th Asian conference on computer vision CY - Daejeon, Korea DA - 05.11.2012 KW - Laser cleaning KW - Multispectral imaging KW - Image restoration KW - Image enhancement PY - 2013 SN - 978-3-642-37483-8 SN - 0302-9743 VL - II IS - LNCS 7729 SP - 13 EP - 24 PB - Springer CY - Berlin Heidelberg AN - OPUS4-28160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pentzien, Simone A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Krüger, Jörg A1 - Kleber, F. A1 - Hollaus, F. A1 - Diem, M. A1 - Sablatnig, R. T1 - Can modern technologies defeat nazi censorship? JF - ACM journal on computing and cultural heritage KW - Laser cleaning KW - Multispectral imaging KW - Image enhancement KW - Ancient manuscripts KW - Image restoration PY - 2010 SN - 1556-4673 VL - 2 IS - 3, Article 1 SP - 1 EP - 16 PB - Association for Computing Machinery CY - New York, NY, USA AN - OPUS4-25651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Mann, Guido A1 - Vogel, Jens A1 - Zoheidi, M. A1 - Eberstein, Markus T1 - Breakdown limits of optical multimode fibers for the application of nanosecond laser pulses at 532 nm and 1064 nm wavelength T2 - EMRS 2008 Spring Meeting, Symposium B: Laser and plasma in micro- and nano-scale materials processing an diagnostics T2 - EMRS 2008 Spring Meeting, Symposium B: Laser and plasma in micro- and nano-scale materials processing an diagnostics CY - Strasbourg, France DA - 2008-05-26 PY - 2008 AN - OPUS4-16900 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mann, Guido A1 - Vogel, Jens A1 - Zoheidi, M. A1 - Eberstein, Markus A1 - Krüger, Jörg T1 - Breakdown limits of optical multimode fibers for the application of nanosecond laser pulses at 532 nm and 1064 nm wavelength JF - Applied surface science N2 - For many applications, optical multimode fibers are used for the transmission of powerful laser radiation. High light throughput and damage resistance are desirable. Laser-induced breakdown at the end faces of fibers can limit their performance. Therefore, the determination of laser-induced damage thresholds (LIDT) at the surface of fibers is essential. Nanosecond (1064 nm and 532 nm wavelength) single-shot LIDT were measured according to the relevant standard on SiO2 glass preforms (Suprasil F300) as basic materials of the corresponding fibers. For 10 kinds of fused silica fibers (FiberTech) with core diameters between 180 µm and 600 µm, an illumination approach utilizing a stepwise increase of the laser fluence on a single spot was used. For both wavelengths, the LIDT values (0% damage probability) obtained by means of the two methods were compared. The influence of surface preparation (polishing) on damage resistance was investigated. For equal surface finishing, a correlation between drawing speed of the fibers and their surface LIDT values was found. In addition to the surface measurements, bulk LIDT were determined for the preform material. KW - Fiber waveguides KW - Physical radiation damage KW - Laser-beam impact phenomena KW - Glasses KW - Radiation treatment PY - 2009 DO - https://doi.org/10.1016/j.apsusc.2008.07.157 SN - 0169-4332 SN - 1873-5584 VL - 255 IS - 10 SP - 5519 EP - 5522 PB - North-Holland CY - Amsterdam AN - OPUS4-19036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Woedtke, T. A1 - Abel, P. A1 - Schröder, K. A1 - Schwock, A. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Biosensor-Membranen mit "Analyt-Fenster" T2 - Proccedings of Sensor 97 T2 - 8. Internationale Messe mit Kongreß für Sensoren, Meßaufnehmer & Systeme ; 8th International Fair with Congress for Sensors, Transducers & Systems CY - Nürnberg, Deutschland DA - 1997-05-13 PY - 1997 VL - 2 SP - 101 EP - 106 PB - ACS Organisations GmbH CY - Wunstorf AN - OPUS4-11959 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Niino, H. T1 - Biomaterial immobilization on polyurethane films by XeCl excimer laser processing JF - Applied physics A N2 - Zusammenfassung The surface chemical modification of polyurethane (PU) films was performed by an UV laser-induced chemical reaction in a polysaccharide solution. This process may be applicable as hydrophilic packaging of implantable medical devices and in vivo sensors. When a PU film in contact with an aqueous alginic acid (AAC) solution was irradiated with a XeCl laser, the PU film turned hydrophilic. Contact angles of water on the film were reduced from 110° to 60°. Since light absorption of the AAC solution at 308 nm was negligibly small, reactive sites were generated solely on the PU surface. There, AAC could be immobilized by chemical bonds thus allowing for a nanometer-scaled grafting of this biomolecule. The mechanism was investigated by surface analyses with Fourier-transform infrared spectroscopy (FT-IR), dye staining, ultraviolet-visible (UV-VIS) spectroscopy, and scanning electron microscopy (SEM) techniques. A one-photon photochemical process could beidentified. PY - 2001 DO - https://doi.org/10.1007/s003390000617 SN - 0947-8396 VL - 72 IS - 1 SP - 53 EP - 57 PB - Springer CY - Berlin AN - OPUS4-926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg A1 - Mann, Guido A1 - Pentzien, Simone T1 - Beam diameter dependence of surface damage threshold of optical multimode fibers and preform material for 532 nm and 1064 nanosecond laser treatment T2 - European Materials Research Society (EMRS) Spring Meeting 2013, Symposium V "Laser materials interactions for micro and nano applications" T2 - European Materials Research Society (EMRS) Spring Meeting 2013, Symposium V "Laser materials interactions for micro and nano applications" CY - Strasbourg, France DA - 2013-05-27 PY - 2013 AN - OPUS4-28810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mann, Guido A1 - Pentzien, Simone A1 - Krüger, Jörg T1 - Beam diameter dependence of surface damage threshold of fused silica fibers and preforms for nanosecond laser treatment at 1064 nm wavelength JF - Applied surface science N2 - Optical fibers made of fused silica are a common method of transmitting high laser pulse energies. Failure of those fibers is a significant risk. The determination of laser-induced damage thresholds (LIDT) on fiber end facets according to ISO 21254 standard is needed. In the past, single pulse nanosecond laser experiments showed an improvement of LIDT with increasing fiber core diameter for 1064 nm wavelength and a constant beam diameter of 50 µm. This paper pays particular attention to the influence of the laser beam diameter on damage resistance. All-silica fiber types (LEONI) with different core diameters (100–600 µm) were investigated using beam diameters in a range from 30 µm to 100 µm. For comparison experiments on fused silica preform material (Heraeus F300) were performed. On one hand, surface LIDT of fused silica preform material decreases significantly with increasing beam size. A model considering a random distribution of point defects explains the experimental data qualitatively. On the other hand, LIDT of fiber end facets stays constant. White light microscopy results suggest that the point defect density on fiber end facets is lower compared to the preform surface due to an excellent surface polish quality. KW - Laser-induced damage threshold KW - Nanosecond laser KW - Optical fiber KW - Fused silica KW - Spot size KW - Defect model PY - 2013 DO - https://doi.org/10.1016/j.apsusc.2013.03.088 SN - 0169-4332 SN - 1873-5584 VL - 276 SP - 312 EP - 316 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-28310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwibbert, Karin A1 - Menzel, F. A1 - Epperlein, N. A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - Bacterial adhesion on femtosecond laser-modified polyethylene JF - Materials N2 - In this study, femtosecond laser-induced sub-micrometer structures are generated to modify polyethylene (PE) surface topographies. These surfaces were subjected to bacterial colonization studies with Escherichia coli and Staphylococcus aureus as test strains. The results reveal that the nanostructures do not influence S. aureus coverage, while the adhesion of E. coli is reduced. KW - Bacterial adhesion KW - Laser-modified surface KW - Polyethylene KW - Laser-induced nanostructures KW - Biofilm PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492280 DO - https://doi.org/10.3390/ma12193107 VL - 12 IS - 19 SP - 3107 PB - MDPI CY - Basel, Schweiz AN - OPUS4-49228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gappenach, C. A1 - Krauß, H.-J. A1 - Krüger, Jörg A1 - Offenhäuser, F. A1 - Pintaske, S. T1 - Auswahl Laserschutzprodukte - eine Handreichung JF - Photonik N2 - Wer mit Laserstrahlung zu tun hat, sollte vor allem auf den Schutz seiner Augen achten, denn die Netzhaut ist eines der empfindlichsten Gewebe des menschlichen Körpers. Auch die Hornhaut des Auges kann durch Laserstrahlung gefährdet sein. Sie hat eine Dicke von nur etwa 0,5 mm. Der Schutz der Augen vor Laserstrahlung ist durch verschiedene Maßnahmen möglich. KW - Laserschutz KW - Schutzbrille KW - Justierbrille KW - Abschirmung KW - EN 207 KW - EN 208 KW - EN 12254 PY - 2015 SN - 1432-9778 VL - 3 SP - 40 EP - 45 PB - AT-Fachverl. CY - Fellbach AN - OPUS4-33431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Area dependence of femtosecond laser-induced periodic surface structures for varying band gap materials after double pulse excitation JF - Applied surface science N2 - The formation of laser-induced periodic surface structures upon irradiation of titanium, silicon, and fused silica with multiple irradiation sequences consisting of parallel polarized Ti:sapphire femtosecond laser pulse pairs (pulse duration 50–150 fs, central wavelength ~800 nm) is studied experimentally. The temporal delay between the individual near-equal energy fs-laser pulses was varied between 0 and 5 ps with a temporal resolution of better than 0.2 ps. The surface morphology of the irradiated surface areas is characterized by means of scanning electron microscopy (SEM). In all materials a decrease of the rippled surface area is observed for increasing delays. The characteristic delay decay scale is quantified and related to material dependent excitation and energy relaxation processes. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Ultrafast optical techniques KW - Mach-Zehnder interferometer PY - 2013 DO - https://doi.org/10.1016/j.apsusc.2012.10.188 SN - 0169-4332 SN - 1873-5584 VL - 278 SP - 7 EP - 12 PB - North-Holland CY - Amsterdam AN - OPUS4-28601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Höhm, S. A1 - Epperlein, Nadja A1 - Spaltmann, Dirk A1 - Rosenfeld, A. A1 - Krüger, Jörg T1 - Applications of laser-induced periodic surface structures (LIPSS) T2 - Proceedings of SPIE N2 - Laser-induced periodic surface structures (LIPSS, ripples) are a universal phenomenon that can be observed on almost any material after the irradiation by linearly polarized laser beams, particularly when using ultrashort laser pulses with durations in the picosecond to femtosecond range. During the past few years significantly increasing research activities have been reported in the field of LIPSS, since their generation in a single-step process provides a simple way of nanostructuring and surface functionalization towards the control of optical, mechanical or chemical properties. In this contribution current applications of LIPSS are reviewed, including the colorization of technical surfaces, the control of surface wetting, the tailoring of surface colonization by bacterial biofilms, and the improvement of the tribological performance of nanostructured metal surfaces. T2 - SPIE Photonics West Conference, Laser-based Micro- and Nanoprocessing XI CY - San Francisco, USA DA - 27.01.2017 KW - Laser-induced periodic surface structures (LIPSS) KW - Laser processing KW - Surface functionalization KW - Application PY - 2017 SN - 978-1-5106-0625-8 SN - 978-1-5106-0626-5 DO - https://doi.org/10.1117/12.2250919 SN - 0277-786X SN - 1996-756X VL - 10092 SP - Article UNSP 100920N, 100920N-1 EP - 100920N-9 PB - SPIE CY - Bellingham, USA AN - OPUS4-39305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Engel, P. A1 - Krüger, Jörg A1 - Lußky, Katharina A1 - Pentzien, Simone T1 - Analyse häufig verwendeter europäischer Papiere. Im Fokus: Fasermaterial, Füllstoffe und Leimung JF - Restauro N2 - Restauratoren können verschiedene Papierarten mit dem bloßen Auge aufgrund von Merkmalen in der Textur und der Oberflächenbeschaffenheit, seinem Aussehen im Durchlicht sowie an Griff und Klang grob unterscheiden. Dabei ist sich der Restaurator stets der Tatsache bewusst, dass es sich lediglich um eine erste grobe Einschätzung handeln kann. Erst bei mikroskopischen Analysen und physikalischen Experimenten treten Charakteristika zu Tage, die eine weitere Annäherung an die Zusammensetzung des Papiers und damit seiner Provenienz erlauben. Gegenstand dieser Arbeit war es, ein europäisches Hadernpapier, ein holzhaltiges Zeichenpapier und ein Whatman®-Filterpapier mit zwei mikroskopischen Methoden und einer Verbrennungstechnik zu untersuchen. Das Fasermaterial, die Füllstoffe, die Leimung und eventuelle Verunreinigungen wurden detailliert evaluiert. Neben konventioneller Lichtmikroskopie kam die weniger bekannte Umweltrasterelektronenmikroskopie (ESEM = Environmental Scanning Electron Microscopy) zum Einsatz, die neben der bildlichen Darstellung der Probenoberflächen zusätzlich eine Elementanalyse derselben gestattet. Letzteres erfordert allerdings das Vorhandensein eines zusätzlichen Röntgenspektrometers. Darüber hinaus wurden die verschiedenen Papiere trocken verascht. Es wurde eine oxidative Zerstörung der organischen Stoffe gewährleistet bis nur noch nichtbrennbare mineralische Asche zu verzeichnen war. Die Komplementarität der eingesetzten Methoden wird demonstriert und ein Einblick in die Zusammensetzung und Struktur der Papiere ermöglicht. Die Analysemethoden sind durch ihren partiell zerstörenden Charakter bzw. Limitierungen hinsichtlich der Objektgröße nur bedingt für die Untersuchung am Original geeignet, sehr wohl aber dafür, das Probenmaterial für Versuchsreihen genau zu definieren und zu standardisieren. PY - 2007 SN - 0933-4017 IS - 7 SP - 472 EP - 477 PB - Callwey CY - München AN - OPUS4-16046 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Aktuelle Ultrakurzpulslaser-Anwendungen an der BAM N2 - Der Vortrag fasst aktuelle Anwendungsgebiete ultrakurzer Laserimpulse in der Materialbearbeitung zusammen. Dabei wird auch die Gefährdung durch unerwünschte Emission von Röntgenstrahlung bei der Überschreitung bestimmter Laserparameter thematisiert. T2 - Anwendertreffen des Laserverbundes Berlin-Brandenburg e.V. CY - Brandenburg, Germany DA - 16.01.2020 KW - Ultrakurze Laserimpulse KW - Materialbearbeitung KW - Oberflächenstrukturierung PY - 2020 AN - OPUS4-50317 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -