Femtosecond laser filamentation with a microlens array in air
Femtosecond laser filamentation with a microlens array in air
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DOI：
10.1364/josab.32.000163
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发表时间：
2015
影响因子：
1.9
通讯作者：
T. Xi;Zhi-Chao Zhao;Z. Hao
中科院分区：
文献类型：
--
作者：
T. Xi;Zhi-Chao Zhao;Z. Hao
通过数值研究，我们表明，在空气中使用微透镜阵列（MLA）传播飞秒激光脉冲时，较早开始的多重丝状化（MF）的整体非线性长度几乎可以延长到单透镜情况下产生的非线性长度的两倍。伸长主要是由于规则细丝的相互作用造成的，规则细丝的位置与小透镜的位置相对应。还观察到超连续谱 (SC) 的增强随波长的变化而变化。通过增加小透镜的数值孔径可以更有效地增强光谱的蓝色一侧，但代价是缩短激光脉冲的整体非线性传播。该过程受到激光脉冲时空动力学的强烈影响。 MLA 为飞秒激光器的长距离应用提供了一种控制丝状化和 SC 发射的新方法。
By performing numerical studies, we show that during the propagation of femtosecond laser pulses with a microlens array (MLA) in air, the overall nonlinear length of multiple filamentation (MF) with an earlier onset can be prolonged almost twice as much as that generated in the case of a single lens. The elongation mainly results from the interaction of the regular filaments whose positions correspond to those of the lenslets. An enhancement of supercontinuum (SC) is also observed with different ratios as a function of wavelength. More efficient enhancement on the blue side of the spectrum can be obtained by increasing the numerical aperture of the lenslets, but at the cost of shortening the overall nonlinear propagation of the laser pulse. This process is strongly influenced by the spatiotemporal dynamics of the laser pulse. The MLA offers a new way to control the filamentation and SC emission for long-distance applications of femtosecond lasers.