文档介绍：
飞秒激光经微透镜阵列在石英中成丝的
控制研究#
刘旭,CAMINO Acner,郝作强,林景全**
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(长春理工大学理学院,长春 130022)
摘要:使用周期性微透镜阵列对飞秒激光聚焦后在熔融石英中形成的细丝进行了研究。研究
表明,通过改变微透镜阵列和石英介质的相对距离, 可以实现细丝的数量及其排布的控制,
实验结果和使用射线追踪程序模拟的结果符合得很好。此外,研究还发现,飞秒激光细丝的
排布强烈依赖于入射激光波长,初始激光能量和偏振态。
关键词:微透镜阵列;等离子体细丝;飞秒激光脉冲
中图分类号:O437
Control of laser filamentation in fused silica by a periodic
microlens array
LIU Xu, CAMINO Acner, HAO Zuoqiang, LIN Jingquan
(School of Science, Changchun University of Science and Technology, ChangChun 130022)
Abstract: Deterministic wavelength-dependent multifilamentation is controlled in fused silica by
adjusting the diffraction pattern generated by a loosely focusing 2D periodic lens array. By simply
translating the sample along the propagation axis the number and distribution of filaments can be
controlled and are in agreement with the results of linear diffraction simulations. The loose
focusing geometry allows for long filaments whose distribution is conserved along their
propagation inside the sample. The effect of incident energy and polarization on filament number
is also studied.
Keywords: microlens array; plasma filament; femtosecond laser pulse
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1 引言
超短强激光脉冲在非线性介质中传输时,由于介质的非线性效应产生的克尔自聚焦会使
激光光束聚焦,当激光功率高于介质的电离阈值时,造成介质的离化而形成等离子体。当等
离子体的散焦作用和克尔自聚焦效应,以及激光光束自身的衍射之间达到动态平衡时,介质
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中就会形成长度远大于激光光束瑞利距离的等离子体细丝[1]。等离子体细丝本身及其表现出
来的各种非线性特性具有重要的应用价值,迄今为止,已经在激光诱导闪电、激光诱导击穿