TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Area dependence of femtosecond laser-induced periodic surface structures for varying band gap materials after double pulse excitation N2 - The formation of laser-induced periodic surface structures upon irradiation of titanium, silicon, and fused silica with multiple irradiation sequences consisting of parallel polarized Ti:sapphire femtosecond laser pulse pairs (pulse duration 50–150 fs, central wavelength ~800 nm) is studied experimentally. The temporal delay between the individual near-equal energy fs-laser pulses was varied between 0 and 5 ps with a temporal resolution of better than 0.2 ps. The surface morphology of the irradiated surface areas is characterized by means of scanning electron microscopy (SEM). In all materials a decrease of the rippled surface area is observed for increasing delays. The characteristic delay decay scale is quantified and related to material dependent excitation and energy relaxation processes. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Ultrafast optical techniques KW - Mach-Zehnder interferometer PY - 2013 U6 - https://doi.org/10.1016/j.apsusc.2012.10.188 SN - 0169-4332 SN - 1873-5584 VL - 278 SP - 7 EP - 12 PB - North-Holland CY - Amsterdam AN - OPUS4-28601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosenfeld, A. A1 - Rohloff, M. A1 - Höhm, S. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Formation of laser-induced periodic surface structures on fused silica upon multiple parallel polarized double-femtosecond-laser-pulse irradiation sequences N2 - The formation of laser-induced periodic surface structures (LIPSS) upon irradiation of fused silica with multiple irradiation sequences of parallel polarized Ti:sapphire femtosecond laser pulse pairs (160 fs pulse duration, 800 nm central wavelength) was studied experimentally. For that purpose, a Michelson interferometer was used to generate near-equal-energy double-pulse sequences allowing the temporal pulse delay between the parallel-polarized individual fs-laser pulses to be varied between 0 and 40 ps with ~0.2 ps temporal resolution. The surface morphologies of the irradiated surface areas were characterized by means of scanning electron and scanning force microscopy. In the sub-ps delay range a strong decrease of the LIPSS periods and the ablation crater depths with the double-pulse delay was observed indicating the importance of the laser-induced free-electron plasma in the conduction band of the solids for the formation of LIPSS. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Fused silica KW - Michelson interferometer PY - 2012 U6 - https://doi.org/10.1016/j.apsusc.2011.09.076 SN - 0169-4332 SN - 1873-5584 VL - 258 IS - 23 SP - 9233 EP - 9236 PB - North-Holland CY - Amsterdam AN - OPUS4-26226 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 - Laser-induced periodic surface structures on fused silica upon cross-polarized two-color double-fs-pulse irradiation 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 U6 - 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 - Höhm, S. A1 - Herzlieb, M. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Dynamics of the formation of laser-induced periodic surface structures (LIPSS) upon femtosecond two-color double-pulse irradiation of metals, semiconductors, and dielectrics N2 - In order to address the dynamics and physical mechanisms of LIPSS formation for three different classes of materials (metals, semiconductors, and dielectrics), two-color double-fs-pulse experiments were performed on Titanium, Silicon and Fused Silica. For that purpose a Mach–Zehnder interferometer generated polarization controlled (parallel or cross-polarized) double-pulse sequences at 400 nm and 800 nm wavelength, with inter-pulse delays up to a few picoseconds. Multiple of these two-color double-pulse sequences were collinearly focused by a spherical mirror to the sample surfaces. The fluence of each individual pulse (400 nm and 800 nm) was always kept below its respective ablation threshold and only the joint action of both pulses lead to the formation of LIPSS. Their resulting characteristics (periods, areas) were analyzed by scanning electron microscopy. The periods along with the LIPSS orientation allow a clear identification of the pulse which dominates the energy coupling to the material. For strong absorbing materials (Silicon, Titanium), a wavelength-dependent plasmonic mechanism can explain the delay-dependence of the LIPSS. In contrast, for dielectrics (Fused Silica) the first pulse always dominates the energy deposition and LIPSS orientation, supporting a non-plasmonic formation scenario. For all materials, these two-color experiments confirm the importance of the ultrafast energy deposition stage for LIPSS formation. KW - Femtosecond laser ablation KW - Double-pulse experiments KW - Laser-induced periodic surface structures (LIPSS) KW - Mach-Zehnder interferometer KW - Ultrafast optical techniques PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0169433215031347 U6 - https://doi.org/10.1016/j.apsusc.2015.12.129 SN - 0169-4332 SN - 1873-5584 VL - 374 SP - 331 EP - 338 PB - Elsevier CY - Amsterdam, Netherlands AN - OPUS4-35938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -