角向偏振无衍射光束的传输特性及其偏振态研究∗

摘要

从理论和实验两个方面研究角向偏振无衍射光束在自由空间和障碍物空间中的传输特性。理论上模拟了角向偏振无衍射光束在自由空间以及障碍物空间传播过程中的光强分布与偏振态变化情况。实验中利用高斯光束先通过偏振转换仪，再入射到轴棱锥上产生角向偏振无衍射光束。进而研究其在空间中的传输情况，并通过分析其经过扇形障碍物后光强分布变化情况讨论障碍物对偏振态的影响和光束的自重建特性。结果表明：障碍物遮挡区域光强沿z轴方向逐渐恢复，且阴影区域沿障碍物所在位置的相反方向移动；光束的偏振态局部发生变化，该变化与障碍物所在位置有关。理论仿真和实验结果一致。%In this paper, the characteristics of the azimuthally polarized non-diffracting beam (APB) propagating in the free space and obstruction space are investigated theoretically and experimentally. The variations in intensity distribution and polarization characteristics of the APB in propagation process are simulated. In the experiment, the APB is generated by using the polarization converter and axicon. And then, we investigate its transmission and analyze the intensity distribution of APB which is behind a sector-shaped opaque obstacle. We also discuss the influences of obstacles on the polarization and self-healing features of the APB. The results show that the light intensity in obstacle block area gradually restores along the z axis and the shadow area moves toward the direction opposite to the location of obstacle. The polarization of the light beam changes partly and the change relates to the obstacle location. Theoretical simulations accord well with experimental results.