TY - CONF A1 - Bonse, Jörn T1 - The role of scattering in the formation of laserinduced periodic surface structures (LIPSS) N2 - Laser-induced periodic surface structures (LIPSS) are a universal phenomenon that is accompanying laser materials processing. These surface nanostructures pave a simple way for surface functionalization with numerous applications in optics, fluidics, tribology, medicine, etc. This contribution reviews the current view on the role of electromagnetic scattering in the formation of LIPSS. T2 - Workshop on Theoretical and Numerical Tools for Nanophotonics (TNTN 2020) CY - Berlin, Germany DA - 12.02.2020 KW - Laser-induced periodic surface structures, LIPSS KW - Electromagnetic scattering KW - Finite-difference time-domain calculations PY - 2020 AN - OPUS4-50399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mermillod-Blondin, A. A1 - Mauclair, C. A1 - Rosenfeld, A. A1 - Bonse, Jörn A1 - Stoian, R. A1 - Audouard, E. T1 - Time-resolved imaging of bulk a-SiO2 upon various ultrashort excitation sequences N2 - Ultrashort pulses lasers are tools of choice for functionalizing the bulk of transparent materials. In particular, direct photoinscription of simple photonic functions have been demonstrated. Those elementary functions rely on the local refractive index change induced when focusing an ultrashort pulse in the volume of a transparent material. The range of possibilities offered by direct photoinscription is still under investigation. To help understanding, optimizing and assessing the full potential of this method, we developed a time-resolved phase contrast microscopy setup. The imaginary part (absorption) and the real part of the laser-induced complex refractive index can be visualized in the irradiated region. The setup is based on a commercially available phase contrast microscope extended into a pump-probe scheme. The originality of our approach is that the illumination is performed by using a pulsed laser source (i.e. a probe beam). Speckle-related issues are solved by employing adequate sets of diffusers. This laser-microscopy technique has a spatial resolution of 650 nm, and the impulse response is about 300 fs. The laser-induced refractive index changes can be tracked up to milliseconds after the energy deposition. The excitation beam (the pump) is focused with a microscope objective (numerical aperture of 0.45) into the bulk of an a-SiO2 sample. The pump beam can be temporally shaped with a SLM-based pulse shaping unit. This additional degree of flexibility allows for observing different interaction regimes. For instance, bulk material processing with femtosecond and picosecond duration pulses will be studied. T2 - Photonics West 2011 CY - San Francisco, CA, USA DA - 22.01.2011 PY - 2011 DO - https://doi.org/10.1117/12.876687 VL - 7925 IS - 79250R SP - 1 EP - 7 AN - OPUS4-23332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Time-resolved imaging of bulk a-SiO2 upon various ultrashort excitation sequences T2 - SPIE Photonics West Conference: Frontiers in Ultrafast Optics: Biomedical, Scientific and Industrial Applications XI (Conference 7925) CY - San Francisco, CA, USA DA - 2011-01-22 PY - 2011 AN - OPUS4-22095 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberstein, M. A1 - Geier, M. A1 - Grießmann, H. A1 - Partsch, U. A1 - Voelkel, L. A1 - Böhme, R. A1 - Pentzien, Simone A1 - Koter, Robert A1 - Mann, Guido A1 - Bonse, Jörn A1 - Krüger, Jörg T1 - Towards an industrial laser doping process for the selective emitter using phosphoric acid as dopant N2 - Different laser supported approaches have already been realized, proving the great potential of laserdoped selective emitters (LDSE). However, it is challenging to establish a low-cost process by using pulsed laser tools. So far a single-step process only leads to satisfying results utilizing cw-lasers. In this paper we have examined a two-step process to produce laser-doped selective emitters on multicrystalline textured standard silicon photovoltaic wafers (90-Ω/sq-Emitter, SiN-antireflection coating (ARC)). The precise ARC removal by near-infrared fs-laser pulses (30 fs, 800 nm), and the doping of uncoated silicon wafers by ns-laser pulses (8 ns, 532 nm) were systematically investigated. In the fs-experiment, optimum conditions for ARC removal were identified. In the nsexperiments under suitable conditions (melting regime), the phosphorous concentration underneath the wafer surface was significantly increased and the sheet resistance was reduced by nearly a factor of two. Moreover, electrical measurements on fired metallization fingers deposited on the laser processed wafers showed low contact resistances. Hence, wafer conditioning with combined fs-laser- and ns-laser-processes are expected to be a promising technology for producing selective emitters. T2 - 26th European photovoltaic solar energy conference and exhibition CY - Hamburg, Germany DA - 05.09.2011 KW - Laser processing KW - Doping KW - Selective emitter KW - Multicrystalline silicon PY - 2011 SN - 3-936338-27-2 DO - https://doi.org/10.4229/26thEUPVSEC2011-2BV.1.2 SP - 1220 EP - 1223 AN - OPUS4-24996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Transient changes of the optical properties of solids during femtosecond laser pulse irradiation and its implications for the formation of lase-induced periodic surface structures T2 - European Materials Research Society (EMRS) Spring Meeting, Symposium R "Laser processing an diagnostics for micro and nano applications" CY - Strasbourg, France DA - 2010-06-07 PY - 2010 AN - OPUS4-20993 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Transient changes of the optical properties of solids during fs-laser pulse irradiation and its implications for the formation of laser-induced periodic surface structures T2 - Forschungsseminar ULTRA des Fachbereichs Naturwissenschaften der Universität Kassel CY - Kassel, Germany DA - 2009-06-22 PY - 2009 AN - OPUS4-19609 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Transient respnse of laser-irradiated solids studied with femtosecond short-wavelength free-electron-lasers T2 - Laser Damage Symposium XLI: Annual Symposium on Optical Materials for High Power Lasers CY - Boulder, CO, USA DA - 2009-09-21 PY - 2009 AN - OPUS4-19629 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Tribological performance of femtosecond laser-induced periodic surface structures on metals T2 - European Materials Research Society (EMRS) Spring Meeting 2014, Symposium J "Laser interaction with advanced materials:fundamentals and applications" CY - Lille, France DA - 2014-05-26 PY - 2014 AN - OPUS4-30918 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Tribological performance of femtosecond laser-induced periodic surface structures on titanium T2 - 16th International Symposium on Laser Precision Microfabrication LPM 2015 CY - Kitakyushu, Fukuka, Japan DA - 2015-05-26 PY - 2015 AN - OPUS4-32598 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn T1 - Tribological performance of femtosecond LIPSS on metals T2 - 4th International workshop on laser-induced periodic surface structures CY - Dolni Brezany, Czech Republic DA - 2014-11-11 PY - 2014 AN - OPUS4-32119 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -