TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Femtosecond laser-induced periodic surface structures on silica N2 - The formation of laser-induced periodic surface structures (LIPSS) on two different silica polymorphs (single-crystalline synthetic quartz and commercial fused silica glass) upon irradiation in air with multiple linearly polarized single- and double-fs-laser pulse sequences (τ = 150 fs pulse duration, λ = 800nm center wavelength, temporal pulse separation Δt < 40 ps) is studied experimentally and theoretically. Two distinct types of fs-LIPSS [so-called low-spatial-frequency LIPSS (LSFL) and high-spatial-frequency LIPSS (HSFL)] with different spatial periods and orientations were identified. Their appearance was characterized with respect to the experimental parameters peak laser fluence and number of laser pulses per spot. Additionally, the 'dynamics' of the LIPSS formation was addressed in complementary double-fs-pulse experiments with varying delays, revealing a characteristic change of the LSFL periods. The experimental results are interpreted on the basis of a Sipe-Drude model considering the carrier dependence of the optical properties of fs-laser excited silica. This new approach provides an explanation of the LSFL orientation parallel to the laser beam polarisation in silica—as opposed to the behaviour of most other materials. KW - High-speed optical techniques KW - Laser beam effects KW - Refractive index KW - Silicon compounds KW - Surface structure PY - 2012 U6 - https://doi.org/10.1063/1.4730902 SN - 0021-8979 SN - 1089-7550 VL - 112 IS - 1 SP - 014901-1 - 014901-9 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-26201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seuthe, T. A1 - Höfner, M. A1 - Reinhardt, F. A1 - Tsai, W.J. A1 - Bonse, Jörn A1 - Eberstein, M. A1 - Eichler, H.J. A1 - Grehn, M. T1 - Femtosecond laser-induced modification of potassium-magnesium silicate glasses: An analysis of structural changes by near edge x-ray absorption spectroscopy N2 - The effects of femtosecond laser pulse irradiation on the glass structure of alkaline silicate glasses were investigated by x-ray absorption near edge structure spectroscopy using the beamline of the Physikalisch-Technische Bundesanstalt at the electron synchrotron BESSY II in Berlin (Germany) by analyzing the magnesium Κ-edge absorption peak for different laser fluences. The application of fluences above the material modification threshold (2.1 J/cm²) leads to a characteristic shift of ~1.0 eV in the Κ-edge revealing a reduced (~3%) mean magnesium bond length to the ligated oxygen ions (Mg-O) along with a reduced average coordination number of the Mg ions. KW - Glass KW - Glass structure KW - Laser beam effects KW - Magnesium compounds KW - Potassium compounds KW - XANES PY - 2012 U6 - https://doi.org/10.1063/1.4723718 SN - 0003-6951 SN - 1077-3118 VL - 100 IS - 22 SP - 224101-1 EP - 224101-3 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-25918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -