Improving axial resolution is paramount importance for three-dimensional optical imaging systems. Here, we investigate the ultimate precision in axial localization using vortex beams. For Laguerre–Gauss (LG) beams, this limit can be achieved with just an intensity scan. The same is not true for superpositions of LG beams, in particular for those with intensity profiles that rotate on defocusing. Microscopy methods based on rotating vortex beams may thus benefit from replacing traditional intensity sensors with advanced mode-sorting techniques.

中文翻译：

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使用涡旋光束进行轴向超定位

提高轴向分辨率对于三维光学成像系统至关重要。在这里，我们使用涡旋光束研究轴向定位的最终精度。对于拉盖尔-高斯 (LG) 光束，只需进行强度扫描即可达到此限制。对于 LG 光束的叠加，情况并非如此，特别是对于那些强度分布在散焦时旋转的光束。因此，基于旋转涡旋光束的显微镜方法可以受益于用先进的模式分类技术取代传统的强度传感器。