基于衍射光学方法,研究了不同阶数的贝塞尔高斯光束经过环形菲涅尔波带片后,在波带片的焦点附近所形成光强分布。入射光束为高阶贝塞尔高斯光束,聚焦区域获得了空心光强分布,入射光束的阶数越高,空心尺寸越大;菲涅尔波带片的数目越多,空心长度越短。入射光束为零阶贝塞尔高斯光束,在聚焦区域获得了针形光束和局域空心光束。这些具有特殊光强分布的光束在激光加工以及粒子囚禁等领域有着潜在应用价值。
Based on the diffraction optical theory, the intensity distribution in the vicinity of the focus of circular Fresnel zone plate formed by Bessel-Gauss beam was studied. Hollow beams were obtained near focus under the illumination of high order Bessel-Gauss beam, the width and the length of central hollow depended on the order of the beam and the number of plate zones. In general, the size of the dark hollow increased with increasing beam order, the length of the dark hollow decreased with increasing number of FZP. Needle beam and bottle beam can be produced under the illumination of zero order Bessel-Gauss beam. These beams with special intensity distribution may have potential applications in laser processing and trapping particles.