二维艾里光束飞秒成丝特性研究

Study on femtosecond laser filamentation characteristics of two-dimensional Airy beams

艾里光束因具有无衍射、自愈和、横向自加速等奇异特性,自被发现以来便成为一个研究热点。对艾里光束的基本理论进行了简单的介绍。利用常用的分步傅里叶数值法对二维艾里光束在空气中的飞秒成丝特性进行了研究。重点计算了二维艾里光束在一定条件下初始光场随传播距离的演化过程。仿真结果表明:当入射的飞秒激光能量足够大时,二维艾里光束在传播很短的距离后便表现出强烈的成丝特性。光丝能量在一定传播距离内会维持较高水平,之后急剧衰减直至光丝消失。所做工作对后续开展相关实验研究具有一定指导意义。

The study of Airy beams has attracted plenty of interests as the beams have the fantastic characteristics of non-diffraction,self-healing and transverse acceleration. The basic theory of Airy beams is briefly introduced. The common split-step Fourier method is utilized to study the femtosecond laser filamentation characteristics of two-dimensional Airy beams in the air. The evolution process of two-dimensional Airy beams＇ initial light field under certain condition is calculated and analyzed in detail. The simulation results indicate that the two-dimensional Airy beams would show strong filamentation characteristics after propagating short distance when the incident energy of femtosecond laser is enough high. The energy of light filaments would keep relatively high during certain propagation distance. But after that,the energy would decrease rapidly and the light filaments would disappear at last. The work will have some guidance significance to the following experimental study.