Heat accumulation effects in femtosecond laser-induced subwavelength periodic surface structures on silicon  

作　　者：付强 钱静 王关德 赵全忠 Qiang Fu;Jing Qian;Guande Wang;Quanzhong Zhao(State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Optics Letters》2023年第5期47-51,共5页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.52175377 and 12174411)。

摘　　要：High-repetition rate femtosecond lasers are shown to drive heat accumulation processes that are attractive for femtosecond laser-induced subwavelength periodic surface structures on silicon.Femtosecond laser micromachining is no longer a nonthermal process,as long as the repetition rate reaches up to 100 kHz due to heat accumulation.Moreover,a higher repetition rate generates much better defined ripple structures on the silicon surface,based on the fact that accumulated heat raises lattice temperature to the melting point of silicon(1687 K),with more intense surface plasmons excited simultaneously.Comparison of the surface morphology on repetition rate and on the overlapping rate confirms that repetition rate and pulse overlapping rate are two competing factors that are responsible for the period of ripple structures.Ripple period drifts longer because of a higher repetition rate due to increasing electron density;however,the period of laser structured surface is significantly reduced with the pulse overlapping rate.The Maxwell–Garnett effect is confirmed to account for the ripple period-decreasing trend with the pulse overlapping rate.

关 键 词：laser materials processing femtosecond laser subwavelength periodic surface structures 

分 类 号：TN248[电子电信—物理电子学]