Analyses of Self-Focusing Phenomenon and Temperature Rise in Fused Silica by Ultrashort Pulse Laser Irradiation
Analyses of Self-Focusing Phenomenon and Temperature Rise in Fused Silica by Ultrashort Pulse Laser Irradiation
复制标题
超短脉冲激光辐照熔融石英自聚焦现象及温升分析
DOI：
10.1016/j.procir.2013.01.002
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Etsuji Ohmura
中科院分区：
文献类型：
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作者：
Kenji Fukuzawa;Qingqing Liu;Takumi Tarukado;Yosuke Kajihara;Ryota Watanabe;Shintaro Itoh;Hedong Zhang;T. Seki;Etsuji Ohmura
当超短脉冲激光照射到可渗透介质的内部时，折射率的变化依赖于电场强度。结果，发生自聚焦现象，并且自聚焦可导致衍射。在光吸收介质中，吸收的光能在超短脉冲激光照射后转变为热能。然后在介质中聚焦区域附近发生熔化或部分烧蚀现象。因此，可以实现内部改性、透气材料的搭接焊接等。利用快速傅里叶变换对含光吸收项的傍轴波动方程进行数值计算，求解了超短脉冲激光照射克尔介质的情况。以吸收能量分布为初始条件，对材料内部进行了传热分析。研究了非线性折射率、强度系数和吸收系数对材料中温度分布的影响。
When an ultrashort pulse laser is irradiated into the inside of a permeable medium, the refractive index changes dependently on the electric field strength. As a result, a self-focusing phenomenon occurs and self-focusing can lead to a filamentation. In the light absorption medium, the absorbed light energy changes to the thermal energy after ultrashort pulse laser irradiation. Then melting or partial ablation phenomena occur near the focusing area in the medium. Therefore, internal modification, lap welding of permeable materials and so on can be achieved. In this study, a paraxial wave equation including light absorption term was solved by numerical calculation using the fast Fourier transform for irradiation of a Kerr medium by an ultrashort pulse laser. Using the absorbed energy distribution as the initial condition, heat transfer analysis in the material was conducted. The influences of the nonlinear index intensity coefficient and the absorption coefficient on the temperature distribution in the material were investigated.