Author Affiliations
Abstract
1 School of Science, Changchun University of Science and Technology, Changchun 130022, China
2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
3 Shandong Provincial Engineering and Technical Center of Light Manipulations & Shandong Provincial Key Laboratory of Optics and Photonic Device, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
We show the intensity control of filamentation in fused silica by temporally shaping the femtosecond laser pulse. The arbitrary control of filamentation intensity has been obtained by the feedback control based on the genetic algorithm, and the peak intensity of filament has changed from about 670 to around 2100 (charge-coupled device counts). This modulation is in qualitative agreement with the simulation results. It is shown that the control of the intensity is realized by modulating the peak power of the shaped pulse.
320.2250 Femtosecond phenomena 320.5540 Pulse shaping Chinese Optics Letters
2019, 17(12): 123201
1 长春理工大学理学院, 吉林 长春 130022
2 中国科学院大学物理科学学院, 北京 101407
利用基于液晶空间光调制器的飞秒激光脉冲整形技术,对飞秒激光在熔融石英中形成等离子体丝的过程进行优化控制研究。实验结果表明:通过脉冲整形可以在固体介质中的指定位置产生等离子体丝。实现了整形脉冲在熔融石英中成丝起点的长距离可控移动,最大移动量达到5.4 mm。通过求解(3+1)维非线性薛定谔方程,对整形脉冲在熔融石英中的成丝过程进行理论模拟研究,得到了与实验一致的结果。研究结果表明:等离子体丝起始位置是由整形飞秒脉冲的中心峰值强度和包络分布决定的。
超快光学 脉冲整形 等离子体丝 遗传算法 成丝起点
Author Affiliations
Abstract
1 State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871, China
2 Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3 Department of Physics, Graduate University of Chinese Academy of Sciences, Beijing 100049, China
4 Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China
The propagation of picosecond deep ultraviolet laser pulse at wavelength of 193 nm in air is numerically investigated. Long plasma channel can be formed due to the competition between Kerr self-focusing and ionization induced defocusing. The plasma channel with electron density of above 10<sup>13</sup>/cm<sup>3</sup> can be formed over 70 m by 50-ps, 20-mJ laser pulses. The fluctuation of laser intensity and electron density inside ultraviolet (UV) plasma channel is significantly lower than that of infrared pulse. The linear absorption of UV laser by air is considered in the simulation and it is shown that the linear absorption is important for the limit of the length of plasma channel.
等离子体通道 自聚焦 深紫外激光 320.5550 Pulses 320.7110 Ultrafast nonlinear optics 320.7090 Ultrafast lasers Chinese Optics Letters
2009, 7(9): 865
1 中国科学院物理研究所，光物理重点实验室，北京 100080
2 中国科学院西安光学精密机械研究所，瞬态光学技术国家重点实验室，陕西 西安 710068
3 Laboratoire de Spectrométrie Ionique et Moléculaire，UMR CNRS 5579，Université Claude Bernard－Lyon 1，43，Bd．du 11 Novembre 1918，F－69622 Villeurbanne Cedex，France
4 中国科学院国家天文台，北京 100012
对超强飞秒激光在空气中传输形成等离子体通道进行了系统研究。空气中长等离子体通道的形成主要是由于光学克尔自聚焦效应，等离子体散焦作用和光束衍射之间达到了动态平衡，使超强飞秒激光脉冲在空气中形成数百米长甚至千米量级长度的等离子体通道。我们发展了通道的四种主要诊断方法：声学诊断、荧光探测、电阻率测量和横截面成像方法，这几种方法各有优势，可以互为补充．研究了通道同时伴随的三次谐波辐射，三次谐波具有与基频激光相似的变化规律。从应用角度出发，我们对通道内细丝进行了优化控制，对通道寿命的延长进行了研究，使通道寿命达到了微秒量级。改变激光脉冲的初始啁啾，得到了更远距离处的稳定成丝分布，和最优化的超连续光谱产生，此外，还介绍了激光诱导高压放电的应用研究。
激光技术 等离子体通道 能量背景 通道寿命 三次谐波 高压放电 laser techniques ionized plasma channel energy reservoir plasma channel lifetime third harmonic emission electrical discharges
