Woodbury D, Goffin A, Schwartz R M, Isaacs J, Milchberg H M
Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA.
Plasma Physics Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA.
Phys Rev Lett. 2020 Sep 25;125(13):133201. doi: 10.1103/PhysRevLett.125.133201.
Nonlinear self-guided propagation of intense long-wave infrared (LWIR) laser pulses is of significant recent interest, as it promises high power transmission without beam breakup and multifilamentation. Central to self-guiding is the mechanism for the arrest of self-focusing collapse. Here, we show that discrete avalanche sites centered on submicron aerosols can arrest self-focusing, providing a new mechanism for self-guided propagation of moderate intensity LWIR pulses in outdoor environments. Our conclusions are supported by simulations of LWIR pulse propagation using an effective index approach that incorporates the time-resolved plasma dynamics of discrete avalanche breakdown sites.
高强度长波红外（LWIR）激光脉冲的非线性自引导传播是近期备受关注的领域，因为它有望实现高功率传输且无光束分裂和多丝化现象。自引导的核心是阻止自聚焦坍缩的机制。在此，我们表明以亚微米气溶胶为中心的离散雪崩位点能够阻止自聚焦，为中等强度LWIR脉冲在户外环境中的自引导传播提供了一种新机制。我们的结论得到了LWIR脉冲传播模拟的支持，该模拟采用了一种有效折射率方法，该方法纳入了离散雪崩击穿位点的时间分辨等离子体动力学。
