TY - GEN A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Dubowski, J. T1 - Femtosecond-pulse laser processing of metallic and semiconducting thin films KW - Femtosekundenpulslaser KW - Pulslaser KW - Dünnschicht, metallisch KW - Dünnschicht, halbleitend KW - Ablation PY - 1995 SN - 0-8194-1750-5 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 2403 SP - 436 EP - 447 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-637 LA - eng 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 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 - 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 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 - Kautek, Wolfgang A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg ED - Meunier, M. T1 - Ultrashort pulse laser interaction with anodic metal oxide layers in electrolyte contact N2 - The removal and accelerated corrosion monitoring of metal coating systems is of general interest in materials science and engineering technology. The femtosecond and nanosecond laser ablation and delamination at 800 nm and 532 nm, respectively, of anodic oxide layers on aluminium alloys in electrolyte contact were investigated. Laser-induced modifications of the oxide layer resulted in an ionic contact between electrolyte and metal, which produced a current transient and thus allowed the in-situ electrochemical monitoring of the modification. Oxide coatings with different optical properties, almost transparent and opaque, were examined. The transparent anodic oxides showed contrasting ablation mechanisms in the nanosecond and femtosecond pulse duration regime: nanosecond pulses caused spallation, whereas femtosecond treatment led to ablation. Current signals measured in the transparent film were consistent with light absorption below the metal-oxide interface and with film spallation. Irradiation of the opaque coating yielded ionic current transients within the so-called shock-affected-zone of the oxide layer. This investigation provided insight into the role of the penetration depth of light and the heat-affected zone, the extent of the shock-affected zone, and the defect formation in the coating and at the solid-solid interface between metal and oxide. 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 - OPUS4-1731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, Ch. A1 - Krausz, F. T1 - Laser micromachining of barium aluminium borosilicate glass with pulse durations between 20 fs and 3 ps KW - Laser micromachining KW - Subpicosecond laser ablation KW - Barium aluminium borosilicate glass PY - 1998 SN - 0169-4332 SN - 1873-5584 IS - 127-129 SP - 892 EP - 898 PB - North-Holland CY - Amsterdam AN - OPUS4-887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - The Femtosecond Pulse Laser: a New Tool for Micromachining KW - Femtosekundenlaser KW - Mikrobearbeitung PY - 1999 SN - 1054-660X SN - 1531-8494 IS - 9,1 SP - 30 EP - 40 PB - MAIK Nauka/Interperiodica Publ. CY - Moscow AN - OPUS4-712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Krausz, F. T1 - Precision laser ablation of dielectrics in the 10-fs regime N2 - Zusammenfassung Laser pulses in the 10-fs domain provide a quality of micromachining of fused silica and borosilicate glass that is unobtainable with longer pulses in the range of several 100 femtoseconds up to picoseconds. The shortening of the pulses reduces the statistical behavior of the material removal and the ablation process thus attains a more deterministic and reproducible character. The improved reproducibility of ablation is accompanied by significantly smoother morphology. This offers the potential for lateral and vertical machining precision of the order of 100 nm and 10 nm, respectively. KW - Laser ablation PY - 1999 DO - https://doi.org/10.1007/s003390050906 SN - 0947-8396 VL - 68 IS - 3 SP - 369 EP - 371 PB - Springer CY - Berlin AN - OPUS4-825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Krivenko, A.G. A1 - Benderskii, V.A. T1 - Gigantic Hydrogen-Ion Discharge Currents Initiated by a Subpicosecond Laser PY - 1998 SN - 0038-5387 SN - 1023-1935 VL - 34 IS - 10 SP - 1068 EP - 1075 PB - MAIK Nauka/Interperiodica Publ. CY - Moscow AN - OPUS4-826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rudolph, Pascale A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Mikrostrukturierung von Glas zur Erzeugung kristalliner Si-Schichten PY - 2000 IS - 12 SP - 7 EP - 36 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-985 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Ultrashort Pulse Laser Interaction with Dielectrics and Polymers N2 - Abstract Femtosecond laser micromachining has excited vivid attention in various industri- al fields and in medicine owing to the advantages of ultrashort laser pulses compared to long-pulse treatment.These are mainly the reduction of the laser fluence needed to induce ablation and the improvement of the contour sharpness of the laser-generated structures. Recently,special attention was paid to femtosecond laser experiments on nonabsorbing in- organic dielectrics.This is due to the fact that optical damage in dielectric optical elements limits the performance of high-power laser systems.Despite the fact that a large variety of organic polymers can be machined with excimer lasers successfully,the involvement of thermal processes can lead to an unsatisfactory quality of the structures.Ultrashort,fs-laser pulses might be an alternative for the treatment of polymers.Therefore,femtosecond laser machining investigations of dielectrics and polymers are reviewed in this paper.Similarities and differences of the ablation behavior of both material classes are discussed.The influ- ence of the bandgap on the ablation threshold in dependence on the pulse duration,the en- hancement of the machining precision with a shortening of the pulse duration,incubation phenomena,and morphological features appearing on the surface after femtosecond laser treatment are mentioned.Possible applications,e.g.,in medicine and biosensors,are de- scribed. KW - Dielectrics KW - Femtosecond laser KW - Micromachining KW - Ablation KW - Polymers PY - 2004 SN - 3-540-40471-6 N1 - Serientitel: Advances in polymer science – Series title: Advances in polymer science IS - 168 SP - 247 EP - 289 PB - Springer CY - Berlin AN - OPUS4-3262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Pentzien, Simone A1 - Conradi, Andrea A1 - Krüger, Jörg A1 - Brzezinka, Klaus-Werner T1 - Pulsed-laser deposition and boron-blending of diamond-like carbon (DLC) thin films KW - Pulslaser KW - Bor KW - Dünnfilmtechnologie KW - Dünnfilm, diamantartig PY - 1996 SN - 0169-4332 SN - 1873-5584 VL - 106 SP - 158 EP - 165 PB - North-Holland CY - Amsterdam AN - OPUS4-630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Rudolph, Pascale A1 - Krüger, Jörg A1 - Rosenfeld, A. A1 - Lorenz, M. A1 - Ashkenasi, D. T1 - Morphological and mechanical investigations of bariumalumoborosilicate glass surfaces processed with 700-fs laser pulses N2 - We present surface micro-modifications of bariumalumoborosilicate glasses with a high transformation temperature near 700 °C. Laser processing of the glass substrate was realized by using ultra-short laser pulses at 800 nm. The morphological conversion of the laser-treated surfaces was characterized by scanning force microscopy and nano-indentation. A hardness increase by at least a factor of six on the laser ablation crater edge relative to illuminated non- ablated areas shows that the material in the crater walls underwent drastic morphological and mechanical changes. In this heat- and shock-affected zone, the material became more elastic as a result of increased stress. T2 - 5th International Conference on Laser Ablation ; COLA '99 CY - Göttingen, Germany DA - 1999-07-19 KW - Bariumalumoborosilicate glass surfaces PY - 1999 DO - https://doi.org/10.1007/s003390051523 SN - 0947-8396 VL - 69 IS - 7 SP - S759 EP - S761 PB - Springer CY - Berlin AN - OPUS4-775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Newesely, H. T1 - Femtosecond-pulse laser ablation of dental hydroxyapatite and single-crystalline fluoroapatite N2 - Laser microdrilling of healthy human enamel and dentine using 300 fs pulses at a wavelength of 615 nm and 3 Hz repetition rate leads to an enhanced structuring quality in comparison with nanosecond-laser results. Microcracking and damage to neighboring tissue can be reduced. Ablation threshold fluences for 100 laser pulses of 0.3 J cm-2 (human dentine), 0.6 J cm-2 (human enamel) and 0.8 J cm-2 (single crystalline fluoroapatite) could be determined. Ablation depths per pulse below 1 7m were observed. T2 - 5th International Conference on Laser Ablation ; COLA '99 CY - Göttingen, Germany DA - 1999-07-19 PY - 1999 DO - https://doi.org/10.1007/s003390051426 SN - 0947-8396 VL - 69 IS - 7 SP - S403 EP - S407 PB - Springer CY - Berlin AN - OPUS4-779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Krausz, F. T1 - Incubation of laser ablation in fused silica with 5-fs pulses N2 - Zusammenfassung The threshold fluences for laser-induced damage of fused silica with single 5-fs pulses from a Ti:sapphire laser system were determined by extrapolating the ablated volume to zero. These thresholds are about 4 times as high as the values previously obtained from multi-shot experiments. This result is interpreted in terms of an irreversible modification of the original material below the single-shot threshold (incubation). KW - Laser PY - 1999 DO - https://doi.org/10.1007/s003390051034 SN - 0947-8396 VL - 69 IS - 4 SP - 465 EP - 466 PB - Springer CY - Berlin AN - OPUS4-799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Krausz, F. T1 - Photoablation with sub-10 fs laser pulses N2 - Ablation experiments in several glasses with single and multishot irradiation by laser pulses in the 10-fs pulse duration domain are presented; physical and technological implications are discussed. We demonstrate that these short pulses offer the potential for lateral and vertical machining precision of the order of 100 nm. KW - Ablation KW - Laser pulses KW - Femtosecond pulses PY - 2000 DO - https://doi.org/10.1016/S0169-4332(99)00432-8 SN - 0169-4332 SN - 1873-5584 VL - 154-155 SP - 11 EP - 16 PB - North-Holland CY - Amsterdam AN - OPUS4-800 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 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 - 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 - 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 - CONF A1 - Kautek, Wolfgang A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg T1 - Femtosecond and Nanosecond Pulse Laser Electrochemistry of Aluminium Alloys 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 - CONF A1 - Kautek, Wolfgang A1 - Krüger, Jörg A1 - Lenzner, Matthias A1 - Martin, Sven A1 - Lenner, M. A1 - Spielmann, C. A1 - Fiedler, A. ED - Meunier, M. T1 - Single- and multi-pulse femtosecond laser ablation of optical filter materials N2 - Commercially available absorption filters (Schott BG18 and BG36) were investigated with respect to their single- and multi-pulse ablation threshold using laser pulses from a Ti:Sapphire laser in the range between 30 and 340 fs. It could be observed, that the threshold fluence decreases for shorter pulse durations. The similarity of the measured multi-pulse threshold fluences with those of undoped glass material (around 1 J/cm^2 for a pulse duration of 30 fs) suggests that, for very short pulses, the threshold is independent on the doping level and therefore, linear absorption does not significantly contribute to laser-induced damage. For >100 pulses per spot and all pulse durations applied, the threshold fluences saturate. This independence on the number of applied pulses leads to technically relevant damage threshold values. 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 - OPUS4-1588 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Niino, Hiroyuki A1 - Yabe, A. T1 - Investigation of excimer laser ablation threshold of polymers using a microphone N2 - KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a microphone. The microphone signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm-2 for PET, 37 mJ cm-2 for PI and 51 mJ cm-2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films. KW - Laser ablation KW - Polymer KW - Treshold KW - Microphone KW - Acoustic measurement KW - Incubation PY - 2002 DO - https://doi.org/10.1016/S0169-4332(02)00418-X SN - 0169-4332 SN - 1873-5584 VL - 197-198 SP - 800 EP - 804 PB - North-Holland CY - Amsterdam AN - OPUS4-1920 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 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 - JOUR A1 - Kautek, Wolfgang A1 - Rudolph, Pascale A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg T1 - Physico-chemical aspects of femtosecond-pulse-laser-induced surface nanostructures N2 - Near-ablation threshold investigations focusing on the generation of periodic nanostructures and their correlation with physico-chemical properties of the solid phase such as e.g., the material-dependent surface energy, were conducted. Molecular dynamic modelling in the sub-picosecond time domain was used to consider ultrafast opto-electronic processes triggering surface reorganization reactions. Fluid containment of solid interfaces showed strong influence on the resulting micro- and nanostructures due to its drastic reduction of the surface energy. The phenomena are discussed in respect to the minimization of the surface free energy in dependence of material composition and interfacial structure. PY - 2005 DO - https://doi.org/10.1007/s00339-005-3211-7 SN - 0947-8396 VL - 81 SP - 65 EP - 70 PB - Springer CY - Berlin AN - OPUS4-7403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mero, M. A1 - Clapp, B. A1 - Jasapara, J.C. A1 - Rudolph, W. A1 - Ristau, D. A1 - Starke, K. A1 - Krüger, Jörg A1 - Martin, Sven A1 - Kautek, Wolfgang T1 - On the damage behavior of dielectric films when illuminated with multiple femtosecond laser pulses N2 - The physical effects reducing the damage threshold of dielectric films when exposed to multiple femtosecond pulses are investigated. The measured temperature increase of a Ta2O5 film scales exponentially with the pulse fluence. A polarized luminescence signal is observed that depends quadratically on the pulse fluence and is attributed to twophoton excitation of self-trapped excitons that form after band-to-band excitation. The damage fluence decreases with increasing pulse number, but is independent of the repetition rate from 1 Hz to 1 kHz at a constant pulse number. The repetition rate dependence of the breakdown threshold is also measured for TiO2 , HfO2, Al2O3, and SiO2 films. A theoretical model is presented that explains these findings. KW - Laser-induced damage KW - Laser materials KW - Ultrafast phenomena KW - Coatings PY - 2005 DO - https://doi.org/10.1117/1.1905343 SN - 0892-354X VL - 44 IS - 5 SP - 051107-1-051107-7 PB - Dekker CY - New York, NY AN - OPUS4-7406 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 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 - JOUR A1 - Daminelli-Widany, Grazia A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Femtosecond laser interaction with silicon under water confinement 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 - GEN A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Staub, M. A1 - Scherer, G.G. ED - Waidelich, W. T1 - Femtosecond-pulse laser micromachining of metal layer composites T2 - 12. Internationalen Kongresses Laser 95 CY - Berlin, Germany DA - 1996-01-01 PY - 1996 SN - 3-540-61316-1 SP - 966 EP - 969 PB - Springer CY - Berlin AN - OPUS4-11958 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 - 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 - GEN A1 - Kautek, Wolfgang A1 - Krüger, Jörg ED - Beyer, E. T1 - Femtosecond pulse laser ablation of metallic, semiconducting, ceramic, and biological materials N2 - Production of holes and grooves of < 30 micrometers diameter with high aspect ratio value is a delicate task either for mechanical tools, or for conventional nanosecond pulse lasers like e.g. pulsed Nd:YAG or excimer lasers. They later tend to cause microcracks extending from an annular melting zone, or substantial disruption, respectively. Experimental results are presented which demonstrate that the development of intense ultrashort pulse laser systems (>> 1012 W cm-2, (tau) < 1 ps) opens up possibilities for materials processing by cold plasma generation and ablation of metals, semiconductors, ceramics, composites, and biological materials. A femtosecond and a nanosecond dye laser with pulse durations of 300 fs (< 200 (mu) J) and 7 ns (< 10 mJ), and center wavelengths at 612 and 600 nm, respectively, both focused on an area of the order of 10-5 cm2, have been applied either to absorbing substrates, like polycrystalline gold, silicon (111), aluminum nitride ceramics, or transparent materials, like synthetic and human dental hydroxyapatite composites, bone material, and human cornea transplants. The fs-laser generates its own absorption in transparent materials by a multiphoton absorption process, and thus forces the absorption of visible radiation. Because the time is too short (< ps) for significant transport of mass and energy, the beam interaction generally results in the formation of a thin plasma layer of approximately solid state density. Only after the end of the subpicosecond laser pulse, it expands rapidly away from the surface without any light absorption and further plasma heating. Therefore, energy transfer (heat and impulse) to the target material, and thermal and mechanical disruption are minimized. In contrast to heat- affected zones (HAZ's) generated by conventional nanosecond pulse lasers of the order of 1 - 10 micrometers , HAZ's of less than 0.02 micrometers were observed. T2 - Conference on Production Line Processes ; Conference on Process Control and Modeling ; Conference on Novel Applications CY - Vienna, Austria DA - 1994-04-05 PY - 1994 SN - 0-8194-1508-1 DO - https://doi.org/10.1117/12.184768 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 2207 SP - 600 EP - 611 PB - SPIE--the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-11892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. ED - Dubowski, J. T1 - Structuring of dielectric and metallic materials with ultrashort laser pulses between 20 fs and 3 ps N2 - Laser-micromachining of barium aluminum borosilicate glass, fused silica and stainless steel has been extended down to a pulse duration of 20 fs generated by a Ti:sapphire laser system at a wavelength of 0.8 micrometer. A systematic study shows that, below 100 fs, an enhanced precision and a substantial decrease of the ablation threshold fluence in comparison to pulse laser processing with pulses in the picosecond and nanosecond range could be achieved. The physical mechanism and the technical relevance of this novel microtechnology is discussed. T2 - Conference CY - San José, CA, USA DA - 1997-02-10 KW - Ablation KW - Laser processing KW - Micromachining KW - Structuring KW - Femtosecond pulse laser KW - Glass KW - Silica KW - Steel PY - 1997 SN - 0-8194-2402-1 DO - https://doi.org/10.1117/12.273740 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 2991 SP - 40 EP - 47 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-11893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Gruber, D. A1 - Husinsky, W. A1 - Grabner, G. A1 - Baumgartner, I. A1 - Scholman, J. A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Waidelich, W. T1 - Nano- and Femtosecond-Laser Processing of Human Donor Corneal-Transplants and Lenticules for Corneal Surgery T2 - 12. Internationaler Kongress Laser 95 CY - Munich, Germany DA - 1995-06-01 PY - 1996 SN - 3-540-61316-1 SP - 397 EP - 400 PB - Springer CY - Berlin AN - OPUS4-11895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kautek, Wolfgang A1 - Sorg, N. A1 - Krüger, Jörg ED - Brieger, M. T1 - Optical second-harmonic generation (SHG) on semiconductor electrodes by means of femtosecond and nanosecond-pulse lasers N2 - In situ optical second-harmonic generation (SHG) on centrosymmetric crystalline semiconductor electrodes opens up a new field of in situ investigations of hurried solid state interfaces and metal front contacts relevant to electronic and photovoltaic devices, which are rarely accessible by other methods. Photoelectrochemical nanosecond- and femtosecond-pulse laser investigations of silicon (111) electrodes show that in situ SHG is feasible in such complex interfacial systems. In a p-p polarization configuration, the azimuthal dependence of the SHG from oxide-covered and bare n-Si (111) electrodes, with and without Ni contact deposits, have been studied. Etching and regrowth of silicon oxides as well as burried interfacial electric field distributions were monitored. In situ SHG is shown to be extremely sensitive to trapped interfacial charge, crystal misorientations and surface step arrays. An advantage of femtosecond-pulses is the fact that illumination fluences that are well below the damage threshold, but still with sufficient power density, can be applied. (Author) T2 - 1st International Symposium on Semiconductor Processing and Characterization with Lasers - Applications in Photovoltaics CY - Stuttgart, Germany DA - 1994-04-18 KW - Femtosecond-Pulse Laser KW - Sub-Picosecond-Pulse Laser KW - Semiconductors KW - Silicon KW - Second-Harmonic Generation KW - SHG KW - Nonlinear Electroreflectance KW - Etch Process KW - Oxide KW - Interfacial Electronic States KW - Fermi-Level Pinning KW - MOS Diode PY - 1995 SN - 0-87849-683-1 DO - https://doi.org/10.4028/www.scientific.net/MSF.173-174.285 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum IS - 173/174 SP - 285 EP - 290 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-11672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kautek, Wolfgang A1 - Krüger, Jörg ED - Brieger, M. T1 - Femtosecond-pulse laser microstructuring of semiconducting materials T2 - 1st International Symposium on Semiconductor Processing and Characterization with Lasers - Applications in Photovoltaics CY - Stuttgart, Germany DA - 1994-04-18 KW - Femtosecond-Pulse Laser KW - Subpicosecond-Pulse Laser KW - Laser-Ablation KW - Multi-Photon Absorption KW - Microstructuring KW - Dry Etching KW - Semiconductors KW - Silicon PY - 1995 SN - 0-87849-683-1 SN - 0255-5476 N1 - Serientitel: Materials science forum – Series title: Materials science forum IS - 173/174 SP - 17 EP - 22 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-11671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Jörg A1 - Sorg, N. A1 - Reif, J. A1 - Kautek, Wolfgang T1 - In situ second harmonic generation measurements during the electrodeposition of Ni on n-Si(111) PY - 1993 SN - 0169-4332 SN - 1873-5584 VL - 69 SP - 388 EP - 392 PB - North-Holland CY - Amsterdam AN - OPUS4-11657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sorg, N. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - SHG Measurements of n-Si(111)/aqueous Solution Interfaces PY - 1993 SN - 0005-9021 VL - 97 IS - 3 SP - 402 EP - 406 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Mitterer, S. A1 - Krüger, Jörg A1 - Husinsky, W. A1 - Grabner, G. T1 - Femtosecond-Pulse Laser Ablation of Human Corneas N2 - A femtosecond pulse laser in the visible spectral region shows promise as a potentially new powerful corneal sculpting tool. It combines the clinical and technical advantages of visible wavelengths with the high ablation quality observed with nanosecond-pulse excimer lasers at 193 nm. A femtosecond and a nanosecond dye laser with pulse durations of 300 fs and 7 ns, and centre wavelengths at 615 nm and 600 nm, respectively, both focused to an area of the order of 10–5 cm2, have been applied to human corneal ablation. Nanosecond laser pulses caused substantial tissue disruption within a 30–100 m range from the excision edge at all fluences above the ablation threshold of F th60 J cm–2 (I th9 GW cm–2). Completely different excisions are produced by the femtosecond-pulse laser: high quality ablations of the Bowman membrane and the stroma tissue characterised by damage zones of less than 0.5 m were observed at all fluences above ablation threshold of F th1 J cm–2 or I th3 TW cm–2 (3×1012 W cm–2). The transparent cornea material can be forced to absorb ultrashort pulses of extremely high intensity. The fs laser generates its own absorption by a multiphoton absorption process. PY - 1994 DO - https://doi.org/10.1007/BF00332446 SN - 0947-8396 VL - 58 IS - 5 SP - 513 EP - 518 PB - Springer CY - Berlin AN - OPUS4-11659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Sorg, N. A1 - Krüger, Jörg T1 - Femtosecond pulse laser second harmonic generation on semiconductor electrodes KW - Femtosecond pulse laser KW - Second harmonic generation (SHG) KW - Electrochemistry KW - Semiconductor electrode KW - Silicon KW - Silicon oxide KW - Oxide growth PY - 1994 SN - 0013-4686 SN - 1873-3859 VL - 39 IS - 8/9 SP - 1245 EP - 1249 PB - Elsevier Science CY - Kidlington AN - OPUS4-11660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Ultrakurze Laserimpulse in der Mikromaterialbearbeitung T2 - Tag der Technik, Fachhochschule für Technik und Wirtschaft (FHTW) CY - Berlin, Germany DA - 2006-05-19 PY - 2006 AN - OPUS4-12305 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Jörg T1 - Short pulse laser processing: safety aspects T2 - Bereichsseminar A - Max Born Institut Berlin CY - Berlin, Germany DA - 2006-11-30 PY - 2006 AN - OPUS4-13779 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 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 - Krivenko, A.G. A1 - Krüger, Jörg A1 - Kautek, Wolfgang A1 - Benderskii, V.A. T1 - Subpicosecond-Pulse-Laser-Induced Electron Emission from Mercury and Silver into Aqueous Electrolytes PY - 1995 SN - 0005-9021 VL - 99 IS - 12 SP - 1489 EP - 1494 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-11782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kautek, Wolfgang A1 - Pentzien, Simone A1 - Krüger, Jörg A1 - König, E. ED - Kautek, W. ED - König, E. T1 - Laser cleaning of ancient parchments T2 - LACONA I CY - Heraklion, Crete, Greece DA - 1995-10-04 PY - 1997 SN - 3-901025-68-5 VL - 18 SP - 69 EP - 78 PB - Mayer CY - Klosterneuburg AN - OPUS4-11784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paatsch, Wolfgang A1 - Kautek, Wolfgang A1 - Krüger, Jörg T1 - Structuring and Plating of Materials with Ultrashort Laser Pulses PY - 2000 SN - 0016-4232 VL - 91 IS - 5 SP - 1271 EP - 1275 PB - Leuze CY - Saulgau, Württ. AN - OPUS4-6000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kautek, Wolfgang A1 - Pentzien, Simone A1 - Röllig, Mathias A1 - Rudolph, Pascale A1 - Krüger, Jörg A1 - Maywald-Pitellos, C. A1 - Bansa, H. A1 - Grösswang, H. A1 - König, E. T1 - Near-UV laser interaction with contaminants and pigments on parchment: laser cleaning diagnostics by SE-microscopy, VIS-, and IR-spectroscopy PY - 2000 SN - 1296-2074 SN - 1778-3674 VL - 1 IS - sup.1 PB - Elsevier CY - Paris AN - OPUS4-5981 LA - deu 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 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 - GEN A1 - Niino, Hiroyuki A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Dubowski, J. ED - Dyer, P. T1 - Photochemical surface modification of polyurethane films with biomaterial by excimer laser processing T2 - 3rd Three-Day Conference on Laser Applications in Microelectronic and Optoelectronic Manufacturing, LAMOM ; LASE ; Photonics West CY - San José, CA, USA DA - 1998-01-26 KW - Laser irradiation surface effects KW - Surface and interface chemistry of polymers KW - Photochemical reactions of biomolecules KW - Biochemical reaction mechanisms and kinetics PY - 1998 SN - 0-8194-2713-6 SN - 1605-7422 N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series IS - 3274 SP - 128 EP - 132 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-12040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boeck, T. A1 - Schmidt, K. A1 - Lorenz, M. A1 - Rosenfeld, A. A1 - Rudolph, Pascale A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Gobrecht, J. T1 - Ultra-short pulse laser seeding techniques for silicon crystallite growth on amorphous substrates T2 - QUANTSOL 99 CY - Wildhaus, Switzerland DA - 1999-03-14 PY - 1999 SP - 1(?) EP - 3(?) AN - OPUS4-12041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Nanometer precision material ablation and optical breakdown with sub-10 fs pulses T2 - 11th International Conference on Ultrafast Phenomena CY - Garmisch-Partenkirchen, Germany DA - 1998-07-12 PY - 1998 SN - 3-540-65430-5 SN - 0172-6218 N1 - Serientitel: Springer Series in chemical physics – Series title: Springer Series in chemical physics IS - 63 SP - 313 EP - 315 PB - Springer CY - Heidelberg AN - OPUS4-12042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lenzner, M. A1 - Sartania, S. A1 - Spielmann, C. A1 - Krausz, F. A1 - Krüger, Jörg A1 - Kautek, Wolfgang T1 - Optical Damage of Dielectrics down to 5 fs T2 - 17th Conference on Lasers and Electro-Optics (CLEO) CY - Baltimore, MD, USA DA - 1997-05-18 PY - 1997 SN - 1-557-52498-X IS - 11 SP - 218 EP - 219 PB - Optical Society of America CY - Washington, DC AN - OPUS4-12043 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) 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 - 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? 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 -