飞秒涡旋激光经倾斜透镜在熔融石英中的成丝特性  

Characteristics of Filamentation of Femtosecond Vortex Laser in Fused Silica with a Tilted Lens

作　　者：刘发倩 李东伟 张中正 张兰芝 郝作强 Liu Faqian;Li Dongwei;Zhang Zhongzheng;Zhang Lanzhi;Hao Zuoqiang(School of Physics and Electronics,Shandong Normal University,Jinan 250358,Shandong,China)

机构地区：[1]山东师范大学物理与电子科学学院,山东济南250358

出　　处：《光学学报》2025年第2期307-313,共7页Acta Optica Sinica

基　　金：国家自然科学基金(12074228,12474310,12204282)。

摘　　要：本文对飞秒涡旋光束经倾斜的聚焦透镜在熔融石英中的成丝分布及其控制进行了研究,通过调节透镜倾斜角度和光束的拓扑荷等参量,获得了规则分布的等离子体细丝阵列。研究表明,通过增加透镜的倾斜角度,光丝分布由环形逐渐过渡到条状分布,并最终呈现阵列分布。此外,改变光束的拓扑荷,还可实现对激光阵列分布的调控。本研究揭示了飞秒涡旋光束在倾斜聚集条件下的成丝分布演化规律,在激光微纳加工等技术领域具有重要参考价值。Objective The uncertainty in the number and position of laser filaments,caused by random noise and competition between filamentation and surrounding energy,severely limits their practical applications.Generating filaments with a regular distribution and a controllable number is therefore crucial for both fundamental research and technological advancements.Recent studies on femtosecond vortex beams have focused primarily on filamentation using conventional focusing lenses.However,tilting the lens can significantly influence filamentation behavior.Previous research has shown that adjusting the lens’s tilt angle allows precise control over the number,distribution,and spatial stability of femtosecond Gaussian laser filaments,effectively managing and suppressing multiple filaments.Moreover,tilted lenses are commonly used to determine a vortex beam’s topological charge,as the beam evolves into a stripe-shaped pattern characterized by alternating bright and dark fringes,with the topological charge calculated as the number of bright spots minus one.In this paper,we explore the filamentation and control of femtosecond vortex beams in fused silica using a tilted lens.Methods Initially,vortex beams with varying topological charges are focused on fused silica using a stationary lens to generate filaments.An imaging lens is used to capture the filament distribution at different propagation distances in fused silica,recorded by a digital camera.The vortex waveplate is replaced to incrementally increase the topological charge of the incident laser beam from 4 to 6 and 8,with corresponding increases in laser power due to higher self-focusing critical power.Linear propagation in air is then studied by removing the fused silica and varying the tilt angles of the focusing lens to examine the intensity distributions at different propagation distances.Subsequently,filamentation is analyzed for vortex beams in fused silica under tilted lens conditions.Finally,vortex beams with different topological charges are focused into fused s

关 键 词：飞秒激光成丝 倾斜透镜 涡旋光束 拓扑荷 

分 类 号：O437.5[机械工程—光学工程]