Polynkin Pavel, Kolesik Miroslav, Moloney Jerome V, Siviloglou Georgios A, Christodoulides Demetrios N
College of Optical Sciences, University of Arizona, Tucson, AZ 85721, USA.
Science. 2009 Apr 10;324(5924):229-32. doi: 10.1126/science.1169544.
Plasma channel generation (or filamentation) using ultraintense laser pulses in dielectric media has a wide spectrum of applications, ranging from remote sensing to terahertz generation to lightning control. So far, laser filamentation has been triggered with the use of ultrafast pulses with axially symmetric spatial beam profiles, thereby generating straight filaments. We report the experimental observation of curved plasma channels generated in air using femtosecond Airy beams. In this unusual propagation regime, the tightly confined main intensity feature of the axially nonsymmetric laser beam propagates along a bent trajectory, leaving a curved plasma channel behind. Secondary channels bifurcate from the primary bent channel at several locations along the beam path. The broadband radiation emanating from different longitudinal sections of the curved filament propagates along angularly resolved trajectories.
在介电介质中使用超强激光脉冲产生等离子体通道(或丝状化)具有广泛的应用,从遥感到太赫兹产生再到闪电控制。到目前为止,激光丝状化一直是通过使用具有轴对称空间光束轮廓的超快脉冲来触发的,从而产生直线状的细丝。我们报告了使用飞秒艾里光束在空气中产生弯曲等离子体通道的实验观察结果。在这种不寻常的传播状态下,轴向非对称激光束紧密受限的主要强度特征沿着弯曲轨迹传播,在后面留下弯曲的等离子体通道。次级通道在沿光束路径的几个位置从主弯曲通道分叉出来。从弯曲细丝的不同纵向部分发出的宽带辐射沿着角度分辨的轨迹传播。