Elongation of filamentation and enhancement of supercontinuum generation by a preformed air density hole

作者：Junwei Chang, Dongwei Li, Litong Xu, Lanzhi Zhang, Tingting Xi, Zuoqiang Hao · 发表于：Optics Express · 年份：2022 · DOI：10.1364/oe.458128 · 被引用次数：18 · 研究领域：Laser-Matter Interactions and Applications、Advanced Fiber Laser Technologies、Laser-Plasma Interactions and Diagnostics

The filamentation of the femtosecond laser pulse in air with a preformed density hole is studied numerically. The result shows that density-hole-induced defocusing effect can relieve the self-focusing of the pulse, and by changing the length of the density hole and relative delay time, the filamentation length, intensity, spectral energy density and broaden region can be effectively controlled. When a short density hole with millisecond delay time is introduced, a significant elongation of the filamentation and enhancement of supercontinuum intensity can be obtained. This study provides a new method to control filamentation by pulse sequence.