非衍射涡旋电磁波自由空间传播特性研究

Research on free⁃space propagation characteristics of non⁃diffracting vortex electromagnetic waves

传统拉盖尔⁃高斯模式涡旋电磁波在自由空间传播时,涡旋波束会随着传播距离的增加而发散,这不仅会导致涡旋波束能量密度的下降,同时也会影响接收端涡旋模态的求解,从而给涡旋电磁波的应用带来困难。文中研究非衍射涡旋电磁波自由空间传播特性,通过对贝塞尔⁃高斯和超几何⁃高斯两种典型非衍射型涡旋电磁波的理论分析,仿真计算这两种涡旋电磁波的空间幅度分布和空间相位分布,并与传统拉盖尔⁃高斯模式涡旋电磁波空间传播特性进行比较。结果表明,不同模态下非衍射涡旋电磁波在远距离自由空间传播的聚束性更好,其在涡旋电磁波空间环境传播工程应用中具有很好的前景。

When the traditional Laguerre-Gaussian mode vortex electromagnetic wave propagates in free space,the vortex beam will diverge with increase of the propagation distance,which not only causes decrease of the vortex beam energy density,but also affects the solving of receiving end vortex mode,so as to bring difficulties for the application of vortex electromagnetic waves.In this paper,the free-space propagation characteristics of non-diffracting vortex electromagnetic waves are studied.The theoretical analysis of two typical non-diffracting vortex electromagnetic waves of Bessel-Gaussian and hypergeometric-Gaussian is carried out to simulate and calculate the spatial amplitude distribution and special phase distribution of these two vortex electromagnetic waves,and compare their characteristics with the vortex electromagnetic wave propagation characteristics of the traditional Laguerre-Gaussian mode.The results show that the non-diffracting vortex electromagnetic waves in different modes have good convergence in long-distance free space propagation.Therefore,it has a good prospect in the application of vortex electromagnetic wave space environment propagation engineering.