发光学报2012，Vol.33Issue(10)：1143-1148,6.DOI:10.3788/fgxb20123310.1143
短脉冲激光加工双温方程的优化运算
Calculation of An Optimized Two Temperature Model for Ultra-short Laser Ablation
摘要
Abstract
Since the pulse duration of femtosecond and sub-picosecond laser are quite short, the electrons and lattice in material can't couple in time when the sample is irradiated by ultra-short pulse laser. According to critical-point phase separation ( CPPS) theory and actual laser ablation process, the thermal conductivity in the model can be restricted regionally. Based on aforementioned analysis, an optimized two temperature model ( TTM ) is formulated, which provides a new perspective into the energy transport process during ultrashort single pulse laser ablation. Using finite element analysis (FEA) software, a model which exhibits the cuprum film sample irradiated by ultra-short pulse laser is proposed. Taking account of symmetrical spatial shape of Gaussian distribution laser on the sample, part of the model is used to calculate simply. According to calculation, the electron-lattice coupling and thermal conduction transient parts in the optimized TTM are analyzed separately. The results indicate that, during ultra-short laser irradiating on cuprum film, the coupling item can be neglected, but the conduction item can't be neglected. The conduction item plays a major role during femtosecond and sub-picosecond laser irradiating on cuprum, while the electron-lattice coupling item plays a major part after laser's effect. With finite element method (FEM) , the optimized ID and 2D TTM model are calculated. For the purpose of ablating sample, suitable laser pulse fluence of 100 fs, 300 fs, 1 ps, 2 ps are applied. The electron and lattice transient temperature distribution evolutions along time in the centre of laser irradiated zone are obtained. For further analysis, according to the spatial lattice temperature distribution, phase separation zone, phase explosion zone and melting zone are calculated.关键词
短脉冲激光/双温方程/有限元/相分离(CPPS)Key words
ultra-short laser pulse/ two temperature model (TTM) / finite element method ( FEM)/ critical-point phase separation(CPPS)分类
信息技术与安全科学引用本文复制引用
金方圆,鄂书林,王海峰,陈波..短脉冲激光加工双温方程的优化运算[J].发光学报,2012,33(10):1143-1148,6.基金项目
国家自然科学基金(10878004/A03)资助项目 （10878004/A03）
