An analysis on two dimensional heat transfer during ultrashort laser heating of thin films

• Main Authors: Chung-Yu Chang, 張毓正
• Other Authors: 許隆結
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/84720339510323033663

碩士 === 中華大學 === 機械與航太工程研究所 === 93 === This study is intent to investigate the effect of two dimensional heat transport phenomena of a thin film subjected to femtosecond laser heating. The dual phase lag model (DPL) was applied to simulate the temperature distribution. The effects of radius of the pulse laser and ratio of delay times on the temperature distributions were discussed in detail.A nondiemensional parameter B was defined as the ratio of time delays of temperature gradient over twice of time delay of heat flux. The radial directional analyses showed that both temperature and energy distributions predicted by DPL model were totally different from those predicted by diffusion and CV wave model. The axial directional analyses also showed a significant two dimensional effect on the temperature distribution. When gold film subjected to pulse laser heating with 95 nm beam radius, results also indicated that one dimensional analyses cause the relative errors on temperature distribution to be about 29%. The error could increase to 70% as time increases to 10 times of the laser pulse duration.