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 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 - 221 IS - 15 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 - Bonse, Jörn A1 - Sokolowski‐Tinten, Klaus T1 - Probing Laser‐Driven Structure Formation at Extreme Scales in Space and Time N2 - Irradiation of solid surfaces with high intensity, ultrashort laser pulses triggers a variety of secondary processes that can lead to the formation of transient and permanent structures over a large range of length scales from mm down to the nano‐range. One of the most prominent examples are LIPSS – Laser‐Induced Periodic Surface Structures. While LIPSS have been a scientific evergreen for of almost 60 years, experimental methods that combine ultrafast temporal with the required nm spatial resolution have become available only recently with the advent of short pulse, short wavelength free electron lasers. Here, the current status and future perspectives in this field are discussed by exploiting the unique possibilities of these 4th‐generation light sources to address by time‐domain experimental techniques the fundamental LIPSS‐question, namely why and how laser irradiation can initiate the transition of a “chaotic” (rough) surface from an aperiodic into a periodic structure. KW - Laser-induced periodic surface structures (LIPSS) KW - Free electron laser KW - Pump-probe experiments KW - Time-resolved scattering KW - Capillary waves PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595048 DO - https://doi.org/10.1002/lpor.202300912 SN - 1863-8899 VL - 18 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-59504 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 - JOUR A1 - Liu, Y. A1 - Gruner, A. A1 - Aboud, D. G. K. A1 - Bonse, Jörn A1 - Schille, J. A1 - Loeschner, U. A1 - Kietzig, A.-M. T1 - Polarization effects on laser-inscribed angled micro-structures N2 - The polarization of the laser beam exhibits more substantial differences in laser micromachining as the angle of incidence deviates from zero. In the reported work, our focus was to explore the effects of circularly, p- and s-polarized laser on angled ultrashort pulse laser micromachining of micropillar arrays. The examination encompassed laser process factors, including angles of incidence, microstructure dimensions, and inter-pillar spacing. A comparison between the resulting structures demonstrated that p-polarized laser beam was the most efficient in material removal in angled laser micromachining, followed by circularly polarized laser. While the s-polarized beam exhibited the lowest ablation efficiency among the three. Such distinction is mainly attributed to the distinguishing reflectivity of the three states of polarization on tilted planes. The development of structural heights during ablation processes was examined, and potential defects in laser processing methodologies were interpreted. The dependency of structural heights on inter-pillar spacing was analyzed. This study bridges the gap between existing studies on angled ultrashort pulse laser machining and the influences of polarization on laser machining. The comparison between structures produced using laboratory-scale and industrial-scale laser systems also yielded pertinent recommendations for facilitating a smooth transition of angled laser micromachining from laboratory-scale research to industrial applications. KW - Laser processing KW - Laser-induced periodic surface structures (LIPSS) KW - Microstructures KW - Nanostructures PY - 2024 UR - https://www.sciencedirect.com/science/article/pii/S0169433223028714 DO - https://doi.org/10.1016/j.apsusc.2023.159191 SN - 0169-4332 VL - 649 SP - 1 EP - 15 PB - Elsevier AN - OPUS4-59329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, Heike A1 - Knigge, Xenia A1 - Knapic, D. A1 - Weise, Matthias A1 - Sahre, Mario A1 - Hertwig, Andreas A1 - Sacco, A. A1 - Rossi, A. M. A1 - Radnik, Jörg A1 - Müller, Kai A1 - Wasmuth, Karsten A1 - Krüger, Jörg A1 - Hassel, A. W. A1 - Hodoroaba, Vasile-Dan A1 - Bonse, Jörn T1 - Picosecond laser processing of hierarchical micro–nanostructures on titanium alloy upon pre- and postanodization: morphological, structural, and chemical effects N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser processing step) plays an important role for the response of bone-forming osteoblasts—an effect that can be utilized for improving permanent dental or removable bone implants. For exploring these different surface functionalities, multimethod morphological, structural, and chemical characterizations are performed in combination with electrochemical pre- and postanodization for two different characteristic microspikes covered by nanometric laser-induced periodic surface structures on Ti–6Al–4V upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ≈1 ps pulse duration, 67 and 80 kHz pulse repetition frequency) at two distinct sets of laser fluence and beam scanning parameters. This work involves morphological and topographical investigations by scanning electron microscopy and white light interference microscopy, structural material examinations via X-ray diffraction, and micro-Raman spectroscopy, as well as near-surface chemical analyses by X-ray photoelectron spectroscopy and hard X-ray photoelectron spectroscopy. The results allow to qualify the mean laser ablation depth, assess the spike geometry and surface roughness parameters, and provide new detailed insights into the near-surface oxidation that may affect the different cell growth behavior for pre- or postanodized medical implants. 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 - Hierarchical micro-nanostructures KW - Laser-induced periodic surface structures (LIPSS) KW - Ultrashort laser pulses KW - Ti-6Al-4V alloy KW - X-ray photoelectron spectroscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601962 DO - https://doi.org/10.1002/pssa.202300920 SN - 1862-6319 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-60196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Paun, I. A. A1 - Heitz, J. A1 - Stoian, R. T1 - Guest editorial: Making light matter N2 - This article represents the Guest Editorial of the Special Issue associated with the Symposium L "Making light matter: lasers in material sciences and photonics" held during the 2023 E-MRS Spring Meeting in Strasbourg, France, June 25th - July 2nd, 2023. 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 - Guest Editorial KW - Laser KW - Material Science KW - Photonics PY - 2024 DO - https://doi.org/10.1002/pssa.202400528 SN - 1862-6319 VL - 221 IS - 15 SP - 1 EP - 5 PB - Wiley-VCH CY - Weinheim AN - OPUS4-60948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hirahara, Kenta A1 - Bonse, Jörn A1 - Krüger, Jörg A1 - Weise, Matthias A1 - Ermilova, Elena A1 - Schusterbauer, Robert A1 - Unterreiner, Andreas-Neil A1 - Hertwig, Andreas T1 - A multi-method study of femtosecond laser modification and ablation of amorphous hydrogenated carbon coatings N2 - e present a study on femtosecond laser treatment of amorphous hydrogen-containing carbon coatings (a-C:H). The coatings were deposited on silicon wafers by a plasma-assisted chemical vapour deposition (PA-CVD), resulting in two different types of material with distinct properties (referred to as “absorbing” and “semi-transparent” coatings in the following). The samples were laser-treated with single fs-laser pulses (800 nm center wavelength, 35 fs pulse duration) in the ablative regime. Through a multi-method approach using topometry, Raman spectroscopy, and spectroscopic imaging ellipsometry, we can identify zones and thresholds of diferent fuence dependent efects and have access to the local dielectric function. The two coating materials react signifcantly diferent upon laser treatment. We determined the (non-ablative) modifcation threshold fuence for the absorbing coating as 3.6 × 10−2 Jcm−2 and its ablation threshold as 0.22 Jcm−2. The semi-transparent coating does not show such a low-fuence modifcation but exhibits a characteristic interference-based intra-flm ablation mechanism with two distinguishable ablation thresholds at 0.25 and 0.28 Jcm−2, respectively. The combination of tailored layer materials and correlative imaging spectroscopic methods delivers new insights into the behaviour of materials when treated with ultrashort-pulse laser radiation KW - Amorphous Hydrogenated Carbon Coatings KW - Correlative Imaging Measurement Techniques KW - Hybrid Metrology KW - Imaging Spectroscopy KW - Spectroscopic Ellipsometry KW - Ultra-short Pulse Laser Materials Processing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-617829 DO - https://doi.org/10.1007/s00339-024-07980-z VL - 130 IS - 12 SP - 1 EP - 17 PB - Springer Science and Business Media LLC AN - OPUS4-61782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voss, Heike A1 - Zahedi-Azad, Setareh A1 - Ernst, Owen C. A1 - Lucaßen, Jan A1 - Mann, Guido A1 - Bonse, Jörn A1 - Boeck, Torsten A1 - Martin, Jens A1 - Schmid, Martina A1 - Krüger, Jörg T1 - Chemical vapor deposition of indium precursors for solar microabsorbers using continuous laser radiation BT - A, Materials science & processing N2 - Localized deposition of indium on an amorphous glass surface covered with a thin molybdenum layer is demonstrated utilizing laser-assisted chemical vapor deposition. A continuous-wave laser causes a temperature rise on the molybdenum layer resulting in the selective aggregation of liquid and ultimately crystalline structures of indium. The formation sites of the indium are determined by the decomposition of gaseous trimethylindium. The deposited indium islands can serve as precursors and could be further processed into compound semiconductors like CuInSe2 for micro-concentrator solar cells. The experimental investigations were supported by theoretical simulations of the laser heating process to calculate the local temperature distribution on the surface of the molybdenum-covered glass substrate. KW - Laser-assisted Chemical Vapor Deposition KW - CW Laser KW - Indium Islands KW - Micro-concentrator Solar Cell PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641069 DO - https://doi.org/10.1007/s00339-025-08895-z SN - 0947-8396 VL - 131 SP - 1 EP - 10 PB - Springer CY - Berlin ; Heidelberg [u.a.] AN - OPUS4-64106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Katrin A1 - Kraft, Sebastian A1 - Weise, Matthias A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - X-ray emission during ultrafast laser grooving N2 - Ultrashort pulse lasers offer the possibility to process materials with minimal heat input and high precision. However, the X-ray emission at high laser peak intensities represents an undesirable side effect. A laser system (1030 nm wavelength, 40 W maximum average laser power, 925 fs pulse duration, 100 μJ maximum pulse energy, 400 kHz pulse repetition frequency) was used to analyze the X-ray skin dose rates for applied peak intensities between 9.2 × 10^12 W/cm^2 and 1.3 × 10^14 W/cm^2 for mild steel, stainless steel and tungsten during groove processing. The lowest laser peak intensity at which X-ray emission could be measured was 9.2 × 10^12 W/cm^2 for processing of stainless steel. The X-ray emission showed a characteristic evolution in dependence on the number of overscans at the same line positions. For low peak intensities, a measurable X-ray emission only begins after a few passes. The number of scans to reach the maximum dose rate increases with lower laser peak intensity. Analysis of the evolving surface topography by white light interference microscopy in connection with ray-tracing simulations led to the interpretation that the increase in X-ray emission is due to the local intensity redistribution by multiple reflection within the laser-generated grooves which is promoted by a particular choice of the linear laser polarization. KW - Ultrashort pulsed laser KW - Laser-induced X-rays KW - X-ray hazard KW - X-ray emission PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639483 DO - https://doi.org/10.1007/s00339-025-08728-z SN - 1432-0630 VL - 131 IS - 8 SP - 1 EP - 12 PB - Springer CY - Berlin AN - OPUS4-63948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martínez, E. A1 - Lejeune, N. A1 - Frechilla, J. A1 - Porta-Velilla, L. A1 - Forneau, E. A1 - Angurel, L. A. A1 - de la Fuente, G. F. A1 - Bonse, Jörn A1 - Silhanek, A. V. A1 - Badía-Majós, A. T1 - Laser engineered architectures for magnetic flux manipulation on superconducting Nb thin films N2 - Custom shaped magnetic flux guiding channels have been fabricated on superconducting Nb thin films by laser nanopatterning of their surface. Preferential pathways are defined by suitable combination of imprinted anisotropic pinning domains through laser-induced periodic surface structures (LIPSS). Generated by the selective energy deposition of femtosecond UV laser pulses, quasi-parallel ripple structures are formed under optimized irradiation conditions. On average, each domain is formed by grooves with a lateral period of 260–270 nm and a depth about 80 nm. By combination of scanning and transmission electron microscopy, magneto-optical imaging, and conductive atomic force microscopy techniques, we conclude that the boundaries of the LIPSS-covered domains play a prominent role in the magnetic flux diversion process within the film. This is confirmed by dedicated modeling of the flux dynamics, combined with the inversion of the magneto-optical signal. The created metasurfaces enable control of the flux penetration process at the microscale. KW - Laser-induced periodic surface structures (LIPSS) KW - Magnetic flux KW - Magneto-optical imaging (MOI) KW - Critical current density PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611243 UR - https://www.sciencedirect.com/science/article/pii/S0169433224019287 DO - https://doi.org/10.1016/j.apsusc.2024.161214 SN - 1873-5584 (Online) SN - 0169-4332 (Print) VL - 679 SP - 1 EP - 12 PB - Elsevier AN - OPUS4-61124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -