Generation of annular beam by a novel class of Fresnel zone plate
Generation of annular beam by a novel class of Fresnel zone plate
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DOI：
10.1364/ao.53.005995
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发表时间：
2014-09-10
期刊：
影响因子：
1.9
通讯作者：
Meshginqalam, Bahar
中科院分区：
文献类型：
--
作者：
Sabatyan, Arash;Meshginqalam, Bahar
本文介绍了一种相位呈径向向外偏移的菲涅耳带板。该FZP可以方便、精确地将入射平面波在其焦平面上转换成环形光束。该方法产生环形梁的优点是效率高、灵活性好。通过直接计算和贝塞尔函数性质，证明了径向位移带板产生环空聚焦。此外，通过模拟修正相结构，除了证明环形焦点的形成外，我们还表明其半径仅取决于位移的大小。我们还表明，环的宽度是焦距的函数。仿真结果经过实验验证。最后，清楚地揭示了沿光束传播距离焦平面一定距离处，环形光束转变为贝塞尔光束，并形成焦线。(C) 2014年美国光学学会
We introduce a type of Fresnel zone plate (FZP) in which its phase is shifted radially outward. This FZP can easily and precisely turn an incident plane wave into an annular beam at its focal plane. High efficiency and flexibility are the advantages of generating doughnut beams by this method. By performing direct calculations and using Bessel function properties, it is shown that a radially shifted zone plate produces annulus focus. Furthermore, by simulating the modified phase structure, in addition to demonstrating the formation of a ring-shaped focus, we also showed that its radius merely depends on the amount of the shift. We also showed that the width of the annulus is a function of focal length. Simulation results were thoroughly examined by experiments. Finally, it is clearly revealed that at a certain distance from the focal plane along the beam propagation, an annular beam is transformed into a Bessel beam, and a focal line is formed. (C) 2014 Optical Society of America