TY - JOUR A1 - Höhm, S. A1 - Herzlieb, M. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Laser-induced periodic surface structures on fused silica upon cross-polarized two-color double-fs-pulse irradiation JF - Applied surface science N2 - The dynamics of the formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration) is studied by cross-polarized two-color double-fs-pulse experiments. In order to analyze the relevance of temporally distributed energy deposition in the early stage of LIPSS formation, a Mach-Zehnder interferometer was used for generating multiple double-pulse sequences at two different wavelengths (400 and 800 nm). The inter-pulse delay between the individual cross-polarized pulses of each sequence was systematically varied in the sub-ps range and the resulting LIPSS morphologies were characterized by scanning electron microscopy. It is found that the polarization of the first laser pulse arriving to the surface determines the orientation and the periodicity of the LIPSS. These two-color experiments further confirm the importance of the ultrafast energy deposition to the silica surface for LIPSS formation, particularly by the first laser pulse of each sequence. The second laser pulse subsequently reinforces the previously seeded spatial LIPSS characteristics (period, orientation). KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Ultrafast optical techniques KW - Mach-Zehnder interferometer PY - 2015 DO - https://doi.org/10.1016/j.apsusc.2014.09.101 SN - 0169-4332 SN - 1873-5584 VL - 336 SP - 39 EP - 42 PB - North-Holland CY - Amsterdam AN - OPUS4-32860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Koter, Robert A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Pentzien, Simone A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg T1 - Tribological performance of femtosecond laser-induced periodic surface structures on titanium and a high toughness bearing steel JF - Applied surface science N2 - Laser-induced periodic surface structures (LIPSS, ripples) were processed on steel (X30CrMoN15-1) and titanium (Ti) surfaces by irradiation in air with linear polarized femtosecond laser pulses with a pulse duration of 30 fs at 790 nm wavelength. For the processing of large LIPSS covered surface areas (5 mm × 5 mm), the laser fluence and the spatial spot overlap were optimized in a sample-scanning geometry. The laser-processed surfaces were characterized by optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM). Spatial LIPSS periods between 450 and 600 nm were determined. The nanostructured surface regions were tribologically tested under reciprocal sliding conditions against a 10-mm diameter ball of hardened 100Cr6 steel. Paraffin oil and engine oil were used as lubricants for 1000 sliding cycles at 1 Hz with a normal load of 1.0 N. The corresponding wear tracks were analyzed by OM and SEM. In particular cases, the laser-generated nanostructures endured the tribological treatment. Simultaneously, a significant reduction of the friction coefficient and the wear was observed in the laser-irradiated (LIPSS-covered) areas when compared to the non-irradiated surface. The experiments reveal the potential benefit of laser surface structuring for tribological applications. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser processing KW - Tribology KW - Metals PY - 2015 DO - https://doi.org/10.1016/j.apsusc.2014.08.111 SN - 0169-4332 SN - 1873-5584 VL - 336 SP - 21 EP - 27 PB - North-Holland CY - Amsterdam AN - OPUS4-32861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Laser-induced periodic surface structures on titanium upon single- and two-color femtosecond double-pulse irradiation JF - Optics express N2 - Single- and two-color double-fs-pulse experiments were performed on titanium to study the dynamics of the formation of laser-induced periodic surface structures (LIPSS). A Mach-Zehnder inter-ferometer generated polarization controlled (parallel or cross-polarized) double-pulse sequences in two configurations – either at 800 nm only, or at 400 and 800 nm wavelengths. The inter-pulse delays of the individual 50-fs pulses ranged up to some tens of picoseconds. Multiple of these single- or two-color double-fs-pulse sequences were collinearly focused by a spherical mirror to the sample surface. In both experimental configurations, the peak fluence of each individual pulse was kept below its respective ablation threshold and only the joint action of both pulses lead to the formation of LIPSS. Their resulting characteristics were analyzed by scanning electron microscopy and the periods were quantified by Fourier analyses. The LIPSS periods along with the orientation allow a clear identification of the pulse which dominates the energy coupling to the material. A plasmonic model successfully explains the delay-dependence of the LIPSS on titanium and confirms the importance of the ultrafast energy deposition stage for LIPSS formation. PY - 2015 DO - https://doi.org/10.1364/OE.23.025959 SN - 1094-4087 VL - 23 IS - 20 SP - 25959 EP - 25971 PB - Optical Society of America CY - Washington, DC AN - OPUS4-34354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Bonse, Jörn A1 - Höhm, S. A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Pentzien, Simone A1 - Koter, Robert A1 - Marschner, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg ED - König, K. ED - Ostendorf, A. T1 - Femtosecond laser-induced surface nanostructures for tribological applications T2 - Optically induced nanostructures: Biomedical and technical applications N2 - Laser-induced periodic surface structures (LIPSS) were generated on two types of steel (100Cr6, X30CrMoN15-1) and two types of titanium (Ti, Ti6A14V) surfaces upon irradiation with multiple linear polarized femtosecond laser pulses in air environment (pulse duration 30 fs, central wavelength 790 nm, pulse repetition rate 1 kHz, Gaussian beam shape). Teh conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning geometry for the processing of large surface areas covered homogeneously by two different types of LIPSS - either near wavelength or sub-100 nm structures. The tribological performance of the nanostructured surfaces was characterized under reciprocating sliding at 1 Hz against a ball of hardened steel using different lubricants and normal forces. After 1000 cycles the corresponding wear tracks were characterized by optical and scanning electron microscopy. For specific conditions, the wear was strongly reduced and laser-generated nanostructures endured the tribological treatment. Simultaneously, a significant reduction of the friction coefficient was observed in the laser-irradiated LIPSS-covered areas, indicating the benefit of laser surface structuring for tribological applications. The spatially Gaussian shaped beam used for the laser processing was transformed via beam shaping into a top hat distribution at the surface of the samples for optimization. The tribological performance of the laser-induced nanostructures is discussed on the basis of different physical and chemical mechanisms. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-332647 SN - 978-3-11-033718-1 SN - 978-3-11-035432-4 DO - https://doi.org/10.1515/9783110354324-011 SP - Chapter 7, 141 EP - 156 PB - De Gruyter AN - OPUS4-33264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Herzlieb, M. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Femtosecond laser-induced periodic surface structures on silicon upon polarization controlled two-color double-pulse irradiation JF - Optics express N2 - Two-color double-fs-pulse experiments were performed on silicon wafers to study the temporally distributed energy deposition in the formation of laser-induced periodic surface structures (LIPSS). A Mach-Zehnder interferometer generated parallel or cross-polarized double-pulse sequences at 400 and 800 nm wavelength, with inter-pulse delays up to a few picoseconds between the sub-ablation 50-fs-pulses. Multiple two-color double-pulse sequences were collinearly focused by a spherical mirror to the sample. The resulting LIPSS characteristics (periods, areas) were analyzed by scanning electron microscopy. A wavelength-dependent plasmonic mechanism is proposed to explain the delay-dependence of the LIPSS. These two-color experiments extend previous single-color studies and prove the importance of the ultrafast energy deposition for LIPSS formation. PY - 2015 DO - https://doi.org/10.1364/OE.23.000061 SN - 1094-4087 VL - 23 IS - 1 SP - 61 EP - 71 PB - Optical Society of America CY - Washington, DC AN - OPUS4-32405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Höhm, S. A1 - Rohloff, M. A1 - Krüger, Jörg A1 - Bonse, Jörn A1 - Rosenfeld, A. ED - Sakabe, S. ED - Lienau, C. ED - Grunwald, R. T1 - Formation of laser-induced periodic surface structures (LIPSS) on dielectrics and semiconductors upon double-femtosecond laser pulse irradiation sequences T2 - Progress in nonlinear nano-optics N2 - The formation of laser-induced periodic surface structures (LIPSS) on different materials (silicon, fused silica, quartz) with linearly polarized fs-laser irradiation is studied experimentally. In dielectrics, the importance of transient excitation stages in the LIPSS formation is demonstrated by using (multiple) cross-polarized double-fs-laser-pulse irradiation sequences. A characteristic decrease of the spatial LIPSS periods is observed for double-pulse delays of less than 2 ps along with a characteristic 90°-rotation of the LIPSS orientation. PY - 2015 SN - 978-3-319-12216-8 SN - 978-3-319-12217-5 DO - https://doi.org/10.1007/978-3-319-12217-5_5 SN - 2192-1970 N1 - Serientitel: Nano-Optics and Nanophotonics – Series title: Nano-Optics and Nanophotonics SP - Chapter 5, 85 EP - 99 PB - Springer AN - OPUS4-32541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -