TY - CONF A1 - Bonse, Jörn A1 - Müller, Kai A1 - Mirabella, Francesca A1 - Knigge, Xenia 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 T1 - Chemical and topographical changes upon sub-100-nm LIPSS formation on titanium alloy N2 - Laser-induced periodic surface structures (LIPSS) have gained remarkable attention as they represent a universal phenomenon that is often accompanying laser-processing. Such LIPSS enable a large variety of different surface functionalizations for applications in the fields of optics, fluidics, tribology, or medicine. Moreover, so-called “high spatial frequency LIPSS” (HSFL) provide an appealing and straightforward way for surface nanostructuring featuring spatial periods even below 100 nm – far beyond the optical diffraction limit. However, the imposed surface functionalities are usually caused by both, topographic and chemical surface alterations. For exploring these effects in detail, multi-method characterizations were performed here for HSFL on processed Ti- 6Al- 4V alloy upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ~1 ps pulse duration, 1 – 400 kHz pulse repetition rate) under different laser and scan processing conditions. The sample characterization involved morphological and topographical investigations by scanning electron microscopy (SEM), atomic force microscopy (AFM), stylus profilometry (SP), and white light interference microscopy (WLIM), as well as near-surface chemical analyses by X-ray photoelectron spectroscopy (XPS), hard X-ray photoelectron spectroscopy (HAXPES) and depth-profiling time-of-flight secondary ion mass spectrometry (TOF-SIMS). The results allow to qualify the laser ablation depth, the geometrical HSFL characteristics and provide detailed insights into the depth extent and the nature of the ps-laser-induced near-surface oxidation. Significance for medical applications will be outlined. T2 - E-MRS Spring Meeting 2023 CY - Strasbourg, France DA - 29.05.2023 KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser processing KW - Hard X-ray photoelectron spectroscopy (HAXPES) KW - Time-offlight secondary ion mass spectrometry (ToF-SIMS) KW - Ti6Al4V alloy PY - 2023 AN - OPUS4-58531 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Wirth, Thomas A1 - Florian, Camilo A1 - Sturm, Heinz A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Chemical effects during the formation of femtosecond laser-induced periodic surface structures N2 - The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects – a fact that is widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometers thick graded oxide layers, consisting mainly of amorphous oxides. Regardless of reduced hardness and limited thickness, this nanostructured surface layer efficiently prevents a direct metal-to-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the used engine oil. T2 - EMRS Spring Meeting 2019, Symposium V “Laser interactions with materials: from fundamentals to applications" CY - Nice, France DA - 27.05.2019 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser KW - Oxidation KW - Tribology PY - 2019 AN - OPUS4-48127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Wirth, Thomas A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Chemical effects in the formation of fs-laser-induced periodic surface structures N2 - The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects - widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometer thick graded oxide layer, consisting mainly of amorphous oxides. Regardless of its reduced hardness and limited thickness, this nanostructured surface layer can effciently prevent a direct metal-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the engine oil involved T2 - 8th International LIPSS Workshop CY - Bochum, Germany DA - 27.09.2018 KW - Laser-induced periodic surface structures, LIPSS KW - Femtosecond KW - Oxidation KW - Tribology PY - 2018 AN - OPUS4-46106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knapic, D. A1 - Mardare, A. I. A1 - Voss, Heike A1 - Bonse, Jörn A1 - Hassel, A. W. T1 - Corrosion study of picosecond-laser structured and anodized Ti6Al4V for bone screws N2 - A corrosion study is performed on six variations of titanium grade 5 (Ti6Al4V) samples. Samples are prepared in different conditions by variation of preanodization, postanodization, and picosecond-laser (ps-laser) surface treatment, while polished and anodized samples serve as reference. Microcones and nanosized periodic surface features are successfully produced on Ti6Al4V samples. The morphology and topography of the structures are visualized by scanning electron microscopy and white light interference microscopy. Furthermore, the relative electrochemically active surface area (ECSA) is determined for the ps-laser-treated samples. It is determined that the preanodized and laser-treated sample has 3.5 times larger ECSA than a polished sample, and that the laser-treated sample has 4.1 times larger area. Moreover, Tafel analysis is performed to determine the corrosion properties of the samples. It is shown that the corrosion resistance improves for both laser-structured samples after the anodization. To further study the surface of the samples, electrochemical impedance spectroscopy measurements are conducted. The study indicates that the ps-laser-treated and anodized Ti6Al4V is suitable to be used for the fabrication of bone screws and plates due to its improved corrosion resistance as compared to nonanodized samples. KW - Laser-induced periodic surface structures (LIPSS) KW - Anodization KW - Bone screws KW - Implant material KW - Titanium alloys PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597890 DO - https://doi.org/10.1002/pssa.202300609 SN - 1862-6319 VL - 221 SP - 1 EP - 8 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-59789 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 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 - Bonse, Jörn A1 - Solis, J. A1 - Spielmann, Ch. A1 - Lippert, Th. A1 - Krüger, Jörg T1 - Damage mechanisms in thin film and bulk polymers upon NIR femtosecond pulse laser irradiation: sub-threshold processes and their implications for laser safety applications T2 - The Internation High-power Laser Ablation Conference 2010 CY - Santa Fe, NM, USA DA - 2010-04-18 PY - 2010 AN - OPUS4-20276 LA - deu 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 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 - Bonse, Jörn A1 - Lasagni, A. F. T1 - Editorial: Laser micro- and nano-material processing – Part 1 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Laser processing KW - Microstructures KW - Nanostructures KW - Applications PY - 2020 DO - https://doi.org/10.1515/aot-2020-0009 SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 1-2 SP - 7 EP - 9 PB - De Gruyter CY - Berlin AN - OPUS4-50797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lasagni, A. F. A1 - Bonse, Jörn T1 - Editorial: Laser micro- and nano-material processing – Part 2 N2 - This special issue of Advanced Optical Technologies (AOT) is dedicated to the field of laser-based micro- and nanostructuring methods. KW - Applications KW - Laser processing KW - Microstructures KW - Nanostructures PY - 2020 DO - https://doi.org/10.1515/aot-2020-0025 SN - 2193-8576 SN - 2193-8584 VL - 9 IS - 3 SP - 111 EP - 112 PB - De Gruyter CY - Berlin AN - OPUS4-50995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Spaltmann, Dirk T1 - Editorial: Special issue "Laser-induced periodic surface nano- and microstructures for tribological applications" N2 - Laser material processing is an emerging technology that generates surface functionalities on the basis of optical, mechanical, or chemical properties. In the form of laser surface texturing (LST), it has attracted a remarkable amount of research to tailor surface properties towards various tribological applications. The main advantages of this single-step, laser-based technology are the contactless machining, featuring a high flexibility, efficiency, and speed, along with the excellent quality of the processed products. LST can be applied precisely localized to sub-micrometric areas, but, via laser beam scanning, it is also feasible for structuring large surface areas at the square meter size. This Special Issue focuses on the latest developments concerning the tribological performance of laser-generated periodic surface nano- and microstructures and their applications. This includes the laser-based processing of different surface patterns, such as “self-organized” laser-induced periodic surface structures (LIPSS, ripples), grooves, micro-spikes, hierarchical hybrid nano-/micro-structures, microfeatures generated by direct laser interference patterning (DLIP), or even dimples or other topographic geometries shaped by direct laser modification or ablation. The applications of these periodically nano- and micro-patterned surfaces may improve the lubricated or non-lubricated tribological performance of surfaces in conformal and even non-conformal contact through a reduction of wear, a variation of the coefficient of friction, altered load carrying capacity, etc., resulting in energy saving, improved reliability, increased lifetimes as well as durability, leading in turn to extended maintenance intervals/reduced down-time. This can be beneficial in terms of bearings, gears, engines, seals, cutting tools, or other tribological components. Fundamental aspects addressed may involve the investigation of the relevant physical and chemical effects accompanying the laser-generated nano- and microscale topographies, such as alterations of the material structures, the hardness, superficial oxidation, the role of additives contained in lubricants, surface wettability, micro-hydrodynamic effects, etc. For this Special Issue we aim to attract both academic and industrial researchers and would like to provide a bridge between research in the fields of tribology and laser material processing in order to foster the current knowledge and present new ideas for future applications and new technologies. KW - Laser-induced periodic surface structures (LIPSS) KW - Tribology KW - Applications KW - Wear KW - Friction PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505948 DO - https://doi.org/10.3390/lubricants8030034 SN - 2075-4442 VL - 8 IS - 3 SP - 34, 1 EP - 34, 3 PB - MDPI CY - Basel AN - OPUS4-50594 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 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 - Bonse, Jörn A1 - Legall, Herbert A1 - Schwanke, Christoph A1 - Krüger, Jörg T1 - Emission von Röntgenstrahlung bei der UKP-Laser-Materialbearbeitung N2 - Der Vortrag stellt Untersuchungen im Rahmen eines BMBF-geförderten Vorhabens zur unerwünschten Emission von Röntgenstahlung bei der Materialbearbeitung mit ultrakurzen Laserpulsen vor. T2 - 7. OptoNet Laserstammtisch “Ultrakurzpulslaser” CY - Jena, Germany DA - 12.03.2019 KW - Laserschutz KW - Materialbearbeitung KW - Röntgenemission KW - Sekundärstrahlung KW - Ultrakurze Laserpulse PY - 2019 AN - OPUS4-47569 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kaczmarek, D. A1 - Albert, T. J. A1 - Munz, Martin A1 - Sturm, Heinz A1 - Bonse, Jörn T1 - Erratum: “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses” [J. Appl. Phys. 97, 013538 (2005)] N2 - This erratum publishes some corrections to the article “Structure formation on the surface of indium phosphide irradiated by femtosecond laser pulses” [J. Appl. Phys. 97, 013538 (2005)]. PY - 2024 DO - https://doi.org/10.1063/5.0222903 SN - 0021-8979 SN - 1089-7550 VL - 136 IS - 4 SP - 1 EP - 2 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-60690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Erzeugung und Charakterisierung anisotroper Nanostrukturen durch Ultrakurzpulslaser N2 - Der Vortrag gibt einen Überblick über die Erzeugung und Charakterisierung anisotroper Nanostrukturen mittels ultrakurzgepulster Laserstrahlung. Besonderes Augenmerk liegt dabei auf dem Phänomen der sogenannten Laser-induzierten periodischen Oberflächen-Nanostrukturen auf dielektrischen Werkstoffen und ihrer zeitlichen Dynamik. Weitere Beispiele von Volumen-Nanostrukturen aus der Literatur werden diskutiert. T2 - 21. Treffen des DGG-DKG Arbeitskreises „Glasig-kristalline Multifunktionswerkstoffe“ CY - Mainz, Germany DA - 22.02.2024 KW - Laser-induzierte periodische Oberflächen-Nanostrukturen KW - Quarzglas KW - Saphir KW - Bessel-Strahlen PY - 2024 AN - OPUS4-59565 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mauclair, C. A1 - Mermillod-Blondin, A. A1 - Mishchik, K. A1 - Bonse, Jörn A1 - Rosenfeld, A. A1 - Colombier, J. P. A1 - Stoian, R. T1 - Excitation and relaxation dynamics in ultrafast laser irradiated optical glasses N2 - We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses (fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural and thermomechanical energy relaxation paths that translate into positive and negative refractive index changes, compression and rarefaction zones. If fast electronic decay occurs at low excitation levels in fused silica via self-trapping of excitons, for carrier densities in the vicinity of the critical value at the incident wavelength, persistent long-living absorptive states indicate the achievement of low viscosity matter states manifesting pressure relaxation, rarefaction, void opening and compaction in the neighboring domains. An intermediate ps-long excited carrier dynamics is observed for BK7 in the range corresponding to structural expansion and rarefaction. The amount of excitation and the strength of the subsequent hydrodynamic evolution is critically dependent on the pulse time envelope, indicative of potential optimization schemes. KW - Ultrafast laser excitation KW - Refractive index engineering KW - Glasses KW - Carrier plasmas KW - Pulse shaping PY - 2016 DO - https://doi.org/10.1017/hpl.2016.45 SN - 2095-4719 SN - 2052-3289 VL - 4 SP - e46, 1 EP - 8 PB - Cambridge University Press AN - OPUS4-38689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Extended Drude-Sipe theory of femtosecond laser-induced periodic surface structures on ZnO T2 - Workshop "ZnO and TiO2 nanostructures" CY - Berlin, Germany DA - 2009-07-09 PY - 2009 AN - OPUS4-19605 LA - deu 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 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 - CONF A1 - Bonse, Jörn A1 - Bachelier, G. A1 - Wiggins, S. M. A1 - Siegel, J. A1 - Solis, J. A1 - Sturm, Heinz T1 - Femtosecond Laser Ablation of Semiconductors: Dynamical, Structural and Morphological T2 - European Materials Research Society (EMRS), Spring Meeting, Symposium Q "Laser and Plasma Processing for Advanced Materials" CY - Strasbourg, France DA - 2009-06-08 PY - 2009 AN - OPUS4-19465 LA - deu 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 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 - GEN A1 - Bonse, Jörn A1 - Baudach, Steffen A1 - Krüger, Jörg A1 - Kautek, Wolfgang ED - Phipps, C. T1 - Femtosecond laser micromachining of technical materials 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 -