State Key Laboratory of Precise Spectroscopy, Department of Physics, East China Normal University, Shanghai, China.
Opt Lett. 2011 Feb 15;36(4):457-9. doi: 10.1364/OL.36.000457.
We propose a handy scheme to generate a vectorial elliptic hollow beam by using a short dual-mode elliptic hollow fiber, study its propagation characteristics in free space, and calculate its total angular momentum at different propagating distances. Our study shows that the resulting elliptic hollow beam has a self-focusing effect in near field, an arbitrary polarization, and a position-dependent fractional angular momentum and that the directions of the major and minor axes of the elliptical intensity profile will be interchanged after the self-focusing plane.
我们提出了一种简便的方案,通过使用短的双模椭圆空芯光纤来产生矢量椭圆空芯光束,研究其在自由空间中的传播特性,并计算其在不同传播距离处的总角动量。我们的研究表明,所得的椭圆空芯光束在近场中具有自聚焦效应、任意偏振以及与位置相关的分数角动量,并且在自聚焦平面之后,椭圆强度分布的长轴和短轴的方向将发生交换。