The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Y. Hernandez - One of the best experts on this subject based on the ideXlab platform.
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Pulsed supercontinuum source of variable Pulse Duration
2013Co-Authors: Philippe Leproux, Vincent Couderc, Y. Hernandez, Anne Bertrand, Marco Andreana, S. Hilaire, Philippe RoyAbstract:A supercontinuum source capable of emitting waves between the infrared range and the ultraviolet range, includes a Pulsed laser source (12) capable of generating a laser beam and a non-linear microstructured optical fibre (14) capable of receiving the laser beam, in such a way that the supercontinuum source is capable of generating a beam (F′) over a Pulse Duration (T′), characterized in that the supercontinuum source includes elements for varying the Pulse Duration.
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Control of near-infrared supercontinuum bandwidth by adjusting pump Pulse Duration
Optics Express, 2012Co-Authors: Marco Andreana, Philippe Leproux, Vincent Couderc, Anne Bertrand, Alexis Labruyère, Alessandro Tonello, S. Wabnitz, C. Duterte, Andras Cserteg, Y. HernandezAbstract:We experimentally and numerically investigated the impact of input pump Pulse Duration on the near-infrared bandwidth of supercontinuum generation in a photonic crystal fiber. We continuously stretched the temporal Duration of the input pump laser (centered at 1030 nm) Pulses from 500 fs up to 10 ps, while keeping fixed the pump peak power. We observed that the long-wavelength edge of the supercontinuum spectrum is increased by 200 nm as the pump Pulse Duration grows from 500 fs to 10 ps. We provide a quantitative fit of the experimental results by means of numerical simulations. Moreover, we have explained the observed spectral broadening enhancement induced by pump Pulse energy by developing an approximate yet fully analytical model for soliton energy exchange through a series of collisions in the presence of stimulated Raman scattering.
A Semerok - One of the best experts on this subject based on the ideXlab platform.
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laser fluence repetition rate and Pulse Duration effects on paint ablation
Applied Surface Science, 2006Co-Authors: F Brygo, A Semerok, Ch Dutouquet, Le F Guern, R Oltra, J M WeulersseAbstract:Abstract The efficiency (mm3/(J Pulse)) of laser ablation of paint was investigated with nanosecond Pulsed Nd:YAG lasers (λ = 532 nm) as a function of the following laser beam parameters: Pulse repetition rate (1–10,000 Hz), laser fluence (0.1–5 J/cm2) and Pulse Duration (5 ns and 100 ns). In our study, the best ablation efficiency (η ≅ 0.3 mm3/J) was obtained with the highest repetition rate (10 kHz) at the fluence F = 1.5 J/cm2. This ablation efficiency can be associated with heat accumulation at high repetition rate, which leads to the ablation threshold decrease. Despite the low thermal diffusivity and the low optical absorption of the paint (thermal confinement regime), the ablation threshold fluence was found to depend on the Pulse Duration. At high laser fluence, the ablation efficiency was lower for 5 ns Pulse Duration than for the one of 100 ns. This difference in efficiency is probably due to a high absorption of the laser beam by the ejected matter or the plasma at high laser intensity. Accumulation of particles at high repetition rate laser ablation and surface shielding was studied by high speed imaging.
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ablation threshold dependence on Pulse Duration for copper
Applied Surface Science, 2002Co-Authors: Masaki Hashida, A Semerok, Guillaume Petite, Y Izawa, O. Gobert, J. F. WagnerAbstract:Abstract Laser ablation of Cu by short Pulse laser (800 nm wavelength, 70 fs Pulse Duration, 0.01–28 J/cm2 fluence range) in air was studied. Three different ablation thresholds were distinguished in all metals. The ablation thresholds for Cu were found to be 0.018, 0.18, and 0.25 J/cm2. The lowest ablation threshold was of one order of magnitude lower than the one observed previously. In the fluence range of 0.018–0.18 J/cm2 the ablation rate was ≈0.01 nm per Pulse. A dependence of the threshold on the Pulse Duration was demonstrated in the range of 70 fs–5 ps. As the laser Pulse Duration increased, the ablation threshold had the tendency to be higher.
J M Weulersse - One of the best experts on this subject based on the ideXlab platform.
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laser fluence repetition rate and Pulse Duration effects on paint ablation
Applied Surface Science, 2006Co-Authors: F Brygo, A Semerok, Ch Dutouquet, Le F Guern, R Oltra, J M WeulersseAbstract:Abstract The efficiency (mm3/(J Pulse)) of laser ablation of paint was investigated with nanosecond Pulsed Nd:YAG lasers (λ = 532 nm) as a function of the following laser beam parameters: Pulse repetition rate (1–10,000 Hz), laser fluence (0.1–5 J/cm2) and Pulse Duration (5 ns and 100 ns). In our study, the best ablation efficiency (η ≅ 0.3 mm3/J) was obtained with the highest repetition rate (10 kHz) at the fluence F = 1.5 J/cm2. This ablation efficiency can be associated with heat accumulation at high repetition rate, which leads to the ablation threshold decrease. Despite the low thermal diffusivity and the low optical absorption of the paint (thermal confinement regime), the ablation threshold fluence was found to depend on the Pulse Duration. At high laser fluence, the ablation efficiency was lower for 5 ns Pulse Duration than for the one of 100 ns. This difference in efficiency is probably due to a high absorption of the laser beam by the ejected matter or the plasma at high laser intensity. Accumulation of particles at high repetition rate laser ablation and surface shielding was studied by high speed imaging.
Costas Fotakis - One of the best experts on this subject based on the ideXlab platform.
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ultraviolet laser microstructuring of silicon and the effect of laser Pulse Duration on the surface morphology
Applied Surface Science, 2006Co-Authors: E Skantzakis, Costas Fotakis, Dimitris G. Papazoglou, Vassilia Zorba, Ioanna ZergiotiAbstract:Abstract The study of the laser Pulse Duration effect on the silicon micro-spikes morphology is presented. The microcones were produced by ultraviolet (248 nm) laser irradiation of doped Si wafers in SF 6 environment. The laser Pulse Duration was adjusted at 450 fs, 5 ps and 15 ns. We have analyzed the statistical nature of the spikes’ morphological characteristics, such as periodicity and apex angle by exploiting image processing techniques, on SEM images of the irradiated samples. The correlation of the quantitative morphological characteristics with the laser parameters (Pulse Duration, laser fluence and number of Pulses) provides new insight on the physical mechanisms, which are involved on the formation of Si microcones.
Marco Andreana - One of the best experts on this subject based on the ideXlab platform.
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Pulsed supercontinuum source of variable Pulse Duration
2013Co-Authors: Philippe Leproux, Vincent Couderc, Y. Hernandez, Anne Bertrand, Marco Andreana, S. Hilaire, Philippe RoyAbstract:A supercontinuum source capable of emitting waves between the infrared range and the ultraviolet range, includes a Pulsed laser source (12) capable of generating a laser beam and a non-linear microstructured optical fibre (14) capable of receiving the laser beam, in such a way that the supercontinuum source is capable of generating a beam (F′) over a Pulse Duration (T′), characterized in that the supercontinuum source includes elements for varying the Pulse Duration.
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Control of near-infrared supercontinuum bandwidth by adjusting pump Pulse Duration
Optics Express, 2012Co-Authors: Marco Andreana, Philippe Leproux, Vincent Couderc, Anne Bertrand, Alexis Labruyère, Alessandro Tonello, S. Wabnitz, C. Duterte, Andras Cserteg, Y. HernandezAbstract:We experimentally and numerically investigated the impact of input pump Pulse Duration on the near-infrared bandwidth of supercontinuum generation in a photonic crystal fiber. We continuously stretched the temporal Duration of the input pump laser (centered at 1030 nm) Pulses from 500 fs up to 10 ps, while keeping fixed the pump peak power. We observed that the long-wavelength edge of the supercontinuum spectrum is increased by 200 nm as the pump Pulse Duration grows from 500 fs to 10 ps. We provide a quantitative fit of the experimental results by means of numerical simulations. Moreover, we have explained the observed spectral broadening enhancement induced by pump Pulse energy by developing an approximate yet fully analytical model for soliton energy exchange through a series of collisions in the presence of stimulated Raman scattering.
