Spatiotemporal evolution of high-aspect-ratio filamentary trace in sapphire of picosecond pulse burst-mode for laser lift-off  

皮秒脉冲序列模式在蓝宝石中高深径比成丝线迹的时空演化

作　　者：SUN Wei-gao YAN Tian-yang WANG Yu-heng JI Ling-fei 孙伟高;燕天阳;王玉恒;季凌飞(Institute of Laser Engineering,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Trans-scale Laser Manufacturing Technology,Ministry of Education,Beijing 100124,China;Research Center of Semiconductor Lighting and Information Engineering Technology(South China University of Technology),Guangzhou 510641,China)

机构地区：[1]Institute of Laser Engineering,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China [2]Key Laboratory of Trans-scale Laser Manufacturing Technology,Ministry of Education,Beijing 100124,China [3]Research Center of Semiconductor Lighting and Information Engineering Technology(South China University of Technology),Guangzhou 510641,China

出　　处：《Journal of Central South University》2022年第10期3304-3311,共8页中南大学学报（英文版）

基　　金：Project(51975017) supported by the National Natural Science Foundation of China;Project(KZ202110005012) supported by the Scientific Research Project of Beijing Educational Committee;China;Project(2018YFB1107500) supported by the National Key R&D Program of China。

摘　　要：The influence of the picosecond(ps) pulsed burst with a nanosecond scale of temporal separation(50 ns) on filamentary traces in sapphire substrate is investigated. The spatiotemporal evolution of the filamentary plasma string induced by sub-pulses of the burst-mode is revealed according to the analysis of the instantaneous photoluminescence images. Due to the presence of residual plasma, the energy loss of sub-pulse during the balancing of self-focusing effect is reduced, and thus refreshes the plasma via refocusing. The refreshed plasma peak generated by the subsequent subpulse appears at relatively low density positions in the formed filamentary plasma string, which results in more uniform densities and less spatial overlap among the plasma peaks. The continuity and uniformity of the filamentary trace in sapphire are enhanced by the burst-mode. Besides, the burst filamentary propagation can also remain effective when the sub-pulse energy is below the self-focusing threshold. Based on this uniform and precise energy propagation mode, the feasibility of its use for the laser lift-off(LLO) process is verified.研究了蓝宝石衬底中皮秒脉冲序列诱发等离子体串的时空演变。残余等离子体的存在,降低了子脉冲在自聚焦效应平衡过程的能量损失,使得后续子脉冲可以通过再聚焦刷新等离子体。刷新后的等离子体峰移动至丝状等离子体串密度相对较低的位置,有效地降低了等离子体峰之间的空间重叠并匀化了等离子体串的密度,最终使得丝状线迹的连续性和均匀性得到增强。基于这种均匀而精确的能量传播模式,验证了其用于激光剥离工艺的可行性。

关 键 词：picosecond laser filamentary plasma string BURST-MODE spatiotemporal evolution laser lift-off 

分 类 号：TN249[电子电信—物理电子学]