文章基本信息

标题：Vortex energy flow in the tight focus of a non-vortex field with circular polarization
本地全文：下载
作者：Victor Kotlyar ; Sergey Stafeev ; Anton Nalimov 等
期刊名称：Computer Optics / Компьютерная оптика
印刷版ISSN：0134-2452
电子版ISSN：2412-6179
出版年度：2020
卷号：44
期号：1
页码：5-11
DOI：10.18287/2412-6179-CO-582
语种：English
出版社：Samarskii Natsional'nyi Issledovatel'skii Universitet imeni Akademika S.P. Koroleva,Samara National Research University
摘要：Using Richards-Wolf formulas, we show that an axisymmetric circularly polarized vortex-free field can be focused into a sharp subwavelength focal spot, around which there is a region where the light energy flow propagates along a spiral. This effect can be explained by the conversion of the spin angular momentum of the circularly polarized field into the orbital angular momentum near the focus, although the on-axis orbital angular momentum remains zero. It is also shown that a linearly polarized optical vortex with topological charge 2 forms near the focal plane an on-axis reverse energy flow (defined by the negative longitudinal component of the Poynting vector) whose amplitude is comparable with the direct energy flow.