TY - CHAP A1 - Beke, S. A1 - Sugioka, K. A1 - Midorikawa, K. A1 - Bonse, Jörn ED - Hemsworth, E.J. T1 - Nanaosecond and femtosecond laser ablation of TeO2 crystals: surface characterization and plasma analysis N2 - Near-IR femtosecond (fs) (pulse duration = 150 fs, wavelength = 775 nm, repetition rate 1 kHz) and VUV nanosecond (ns) (pulse duration = 20 ns, wavelength = 157 nm, repetition rate 1 to 5 Hz) laser pulse ablation of single-crystalline TeO2 (c-TeO2 ) surfaces was performed in air using the direct focusing technique. A multi-method characterization using optical microscopy, atomic force microscopy and scanning electron microscopy revealed the surface morphology of the ablated craters. This allowed us at each irradiation site to characterize precisely the lateral and vertical dimensions of the laser-ablated craters for different laser pulse energies and number of laser pulses per spot. Based on the obtained information, we quantitatively determined the ablation threshold fluence for the fs laser irradiation when different pulse numbers were applied to the same spot using two independent extrapolation techniques. We found that in the case of NIR fs laser pulse irradiation, the ablation threshold significantly depends on the number of laser pulses applied to the same spot indicating that incubation effects play an important role in this material. In the case of VUV ns laser pulses, the ablation rate is significantly higher due to the high photon energy and the predominantly linear absorption in the material. These results are discussed on the basis of recent models of the interaction of laser pulses with dielectrics. In the second part of this chapter, we use time- of-flight mass spectrometry (TOFMS) to analyze the elemental composition of the ablation products generated upon laser irradiation of c-TeO2 with single fs- (pulse duration ~200 fs, wavelength 398 nm) and ns-pulses (pulse duration 4 ns, wavelength 355 nm). Due to the three order of magnitude different peak intensities of the ns- and fs laser pulses, significant differences were observed regarding the laser-induced species in the plasma plume. Positive singly, doubly and triply charged Te ions (Te+, Te2+, Te3+) in the form of many different isotopes were observed in case of both irradiations. In the case of the ns-laser ablation, the TeO+ formation was negligible compared to the fs case and there was no Te trimer (Te3+) formation observed. It was found that the amplitude of Te ion signals strongly depends on the applied laser pulse energy. Singly charged oxygen ions (O+) are always present as a byproduct in both kinds of laser ablation. KW - Tellurium dioxide crystals KW - Femtosecond laser ablation KW - VUV nanosecond laser ablation KW - Multiphoton absorption KW - Time-of-flight mass spectroscopy KW - Incubation KW - Optical properties KW - Scanning electron microscopy KW - Atomic force microscopy KW - Isotopes PY - 2011 SN - 978-1-61324-851-5 N1 - Serientitel: Physics Research and Technology – Series title: Physics Research and Technology IS - Chapter 4 SP - 77 EP - 96 PB - Nova Science Publishers, Inc. AN - OPUS4-25454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Beke, S. A1 - Sugioka, K. A1 - Midorikawa, K. A1 - Bonse, Jörn ED - Hemsworth, E.J. T1 - Nanosecond and femtosecond laser ablation of TeO2 crystals: surface characterization and plasma analysis N2 - Near-IR femtosecond (fs) (pulse duration = 150 fs, wavelength = 775 um, Repetition rate 1 kHz) and VUV nanosecond (ns) (pulse duration = 20 ns, wavelength = 157 nm, repetition rate 1 to 5 Hz) laser pulse ablation of single-crystalline TeO? (c-Te02) surfaces was performed in air using the direct focusing technique. A multi-method characterization using optical microscopy, atomic force microscopy and scanning electron microscopy revealed the surface morphology of the ablated craters. This allowed us at each irradiation site to characterize precisely the lateral and vertical dimensions of the laser-ablated craters for different laser pulse energies and number of laser pulses per spot. Based on the obtained information, we quantitatively determined the Ablation threshold fluence for the fs laser irradiation when different pulse numbers were applied to the same spot using two independent extrapolation techniques. We found that in the case of NIR fs laser pulse irradiation, the ablation threshold significantly depends on the number of laser pulses applied to the same spot indicating that incubation effects play an important role in this material. In the case of VUV ns laser pulses, the ablation rate is significantly higher due to the high photon energy and the predominantly linear absorption in the material. These results are discussed on the basis of recent models of the interaction of laser pulses with dielectrics. In the second part of this chapter, we use timeof-flight mass spectrometry (TOFMS) to analyze the elemental composltion of the ablation products generated upon laser irradiation of c-Te02 with single fs- (pulse duration ~ 200 fs, wavelength 398 nm) and ns-pulses (pulse duration 4 ns, wavelength 355 nm). Due to the three Order of magnitude different peak intensities of the ns- and fs laser pulses, significant differences were observed regarding the laser-induced species in the plasma plume. Positive singly, doubly and triply charged Te ions (Te+, Te2+, Te3+) in the form of many different isotopes were observed in case of both irradiations. In the case of the ns-laser ablation, the TeO+ formation was negligible compared to the fs case and there was no Te trimer (Te3+) formation observed. It was found that the amplitude of Te ion Signals strongly depends on the applied laser pulse energy. Singly charged Oxygen ions (0+) are always present as a byproduct in both kinds of laser ablation. KW - Femtosecond laser ablation KW - Nanosecond laser ablation KW - Damage threshold KW - TeO2 KW - Dielectrics KW - Time-of-flight mass spectrometry (TOF-MS) PY - 2011 SN - 978-1-61324-851-5 N1 - Serientitel: Physics Research and Technology – Series title: Physics Research and Technology IS - Chapter 4 SP - 77 EP - 96 PB - Nova Science Publishers, Inc. AN - OPUS4-25465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beke, S. A1 - Kobayashi, T. A1 - Sugioka, K. A1 - Midorikawa, K. A1 - Bonse, Jörn T1 - Time-of-flight mass spectroscopy of femtosecond and nanosecond laser ablated TeO2 crystals N2 - Single-pulse femtosecond (fs) (pulse duration ~200 fs, wavelength 398 nm) and nanosecond (ns) (pulse duration 4 ns, wavelength 355 nm) laser ablation have been applied in combination with time-of-flight mass spectrometer (TOFMS) to analyze the elemental composition of the plasma plume of single-crystalline telluria (c-TeO2, grown by the balance controlled Czochralski growth method). Due to the three-order difference of the peak intensities of the ns and fs-laser pulses, significant differences were observed regarding the laser-induced species in the plasma plume. Positive singly, doubly and triply charged Te ions (Te+, Te2+, Te3+) in the form of their isotopes were observed in case of both irradiations. In case of the ns-laser ablation the TeO+ formation was negligible compared to the fs case and there was no Te trimer (Te3+) formation observed. It was found that the amplitude of Te ion signals strongly depended on the applied laser pulse energy. Singly charged oxygen ions (O+) are always present as a byproduct in both kinds of laser ablation. KW - Time-of-flight mass spectroscopy KW - Tellurium dioxide crystals KW - second laser KW - Nanosecond laser KW - Ablation PY - 2011 U6 - https://doi.org/10.1016/j.ijms.2010.08.022 SN - 0168-1176 SN - 0020-7381 SN - 1387-3806 SN - 1873-2798 VL - 299 IS - 1 SP - 5 EP - 8 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-22490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -