通过对由两个零级贝塞尔光束相干叠加形成的三维衍射光场的理论分析和计算机模拟,发现当双零级贝塞尔光束的有关参量满足一定条件时,会在光轴上形成一系列高质量的局域空心光束。在此基础上,进一步分析了这种阵列局域空心光束的大小、阵列周期及局域空心光束的质量与双零级贝塞尔光束和光路参量的定量关系。推导出双零级贝塞尔光束叠加时在中心暗斑位置达到完全干涉相消的条件是通过两个环缝的能量要相同,以及产生最佳局域空心光束的内外环缝光源半径的比值为0.465。该研究为进一步设计制备基于双零级贝塞尔光束干涉实现阵列局域空心光束的新型衍射光学元件提供了理论依据和设计参量。

Three-dimensional (3D) intensity distribution of double zero-order Bessel beams is theoretically analyzed and simulated in computer. It is found that a chain of three-dimensional localized hollow beams can be generated by interference of the double zero-order Bessel beams. Dependence of the size, the spatial period and the quality of these localized hollow beams on the parameters of the double zero-order Bessel beams are discussed quantitatively. The condition for zero intensity at the central points of the localized hollow beams is given. We also found that the optimal localized hollow beams can be generated only when the radial ratio of the inner to outer rings is taken as a special value. This research is significant for design of new diffractive optical elements to generate localized hollow beams based on interference of the double zero-order Bessel beams.