高度局域线偏振时空光涡旋的生成方法

Method for generating highly confined linearly polarized spatiotemporal optical vortices

携带横向轨道角动量的时空光涡旋是一种新型光脉冲波包,受到越来越多的关注。本文报道一种经过高数值孔径透镜聚焦,在透镜焦平面上产生偏振态可控的线偏振时空光涡旋的方法。为克服聚焦透镜对入射时空涡旋产生的时空像散效应,需对入射时空波包作预劈裂处理。基于Richards Wolf矢量衍射公式仿真了不同偏振态下的高度局域时空涡旋的三维时空场分布,并对其强度和相位特性进行了分析。生成的水平偏振、垂直偏振以及45°偏振高度局域时空涡旋证明了本文所提方法的有效性。

Spatiotemporal optical vortices(STOVs) carrying transverse orbital angular momentum are a new type of optical pulse wave packet, and attract more and more attention from researchers around the world. In this paper, we present a method of generating linearly polarized STOVs with controllable polarization states on the focal plane of a high numerical aperture lens. The incident wave packet is pre-split to overcome the spatiotemporal astigmatism caused by the focusing lens to the STOV. The three dimensional spatiotemporal distributions of the highly confined STOVs with different polarization states are simulated based on Richards Wolf vectorial diffraction theory to analyze their intensity and phase characteristics. The obtained horizontally polarized, vertically polarized and 45° polarized highly confined STOVs manifest the feasibility of the presented method.