Browsing by Author "Chen, J. K."

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Ablation of Copper by a Single Ultrashort Laser Pulse
(2014-06-01)
Wang, S. Y.
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Ren, Y. P.
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Chang, K. P.
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Cheng, C. W.
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Chen, J. K.
Thermal ablation of copper films by a single Ti:Sapphire femtosecond laser pulse of wavelength 800 nm and duration 100 fs was investigated experimentally and theoretically. The laser experiments were performed; the ablation depth and crater profiles were measured for laser fluences up to 1037 J/cm(2). A comprehensive axisymmetric model, including a two-temperature model, phase change models for rapid melting and evaporation, and a phase explosion model for ejecting metastable liquid and vapor, was developed to simulate the laser material ablation process. The simulated ablation depths and crater profiles agree well with the experimental measurements.
Femtosecond laser ablation of copper at high laser fluence: Modeling and experimental comparison
(2016-01-15)
Cheng, C. W.
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Wang, S. Y.
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Chang, K. P.
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Chen, J. K.
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機械工程學系
Thermal ablation of a copper foil surface by a single femtosecond laser pulse of duration 120 fs and wavelength 800 nm was investigated herein both theoretically and experimentally. A 1D two-temperature model with temperature-dependent material properties was considered, including the extended Drude model for dynamic optical properties. The rapid phase change and phase explosion models were incorporated to simulate the material ablation process. The simulated ablation depths agree well with the experimental measurements for the high laser fluence regime ranging from 6.1 to 63.4 j/cm(2). (C) 2015 Elsevier B.V. All rights reserved.
Femtosecond laser sintering of copper nanoparticles
(2016-04)
Cheng, C. W.
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Chen, J. K.
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機械工程學系
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Department of Mechanical Engineering
The ultrafast melting of copper nanoparticles (NPs) induced by a femtosecond laser pulse with duration of 100 fs and wavelength of 800 nm is investigated theoretically and experimentally. The Cu pattern fabricated from sintering of a Cu NP-dispersed film by the femtosecond laser at a repetition rate of 80 MHz is experimentally studied. A one-dimensional two-temperature model with temperature-dependent material properties, including the extended Drude model for dynamic optical properties and the thermophysical properties, is employed to simulate the particles ultrafast melting and re-solidification process.