Electromagnetic waves possessing orbital angular momentum (OAM) are powerful tools for applications in optical communications, quantum technologies, and optical tweezers. Recently, they have attracted growing interest since they can be harnessed to detect peculiar helical dichroic effects in chiral molecular media and in magnetic nanostructures. In this work, we perform single-shot per position ptychography on a nanostructured object at a seeded free-electron laser, using extreme ultraviolet OAM beams of different topological charge orders \ell$\ell$ generated with spiral zone plates. By controlling \ell$\ell$, we demonstrate how the structural features of OAM beam profiles determine an improvement of about 30% in image resolution with respect to conventional Gaussian beam illumination. This result extends the capabilities of coherent diffraction imaging techniques, and paves the way for achieving time-resolved high-resolution (below 100 nm) microscopy on large area samples.

中文翻译：

---

使用 OAM 光束在种子自由电子激光源上进行高分辨率叠层成像

具有轨道角动量（OAM）的电磁波是光通信、量子技术和光镊应用的强大工具。最近，它们引起了越来越多的兴趣，因为它们可以用来检测手性分子介质和磁性纳米结构中特殊的螺旋二向色效应。在这项工作中，我们使用由螺旋波带片产生的不同拓扑电荷顺序的极紫外 OAM 光束，在种子自由电子激光器上对纳米结构物体进行单次每位置叠层成像$\ell$。通过控制\ell$\ell$，我们演示了 OAM 光束轮廓的结构特征如何决定图像分辨率相对于传统高斯光束照明提高约 30%。这一结果扩展了相干衍射成像技术的能力，并为在大面积样品上实现时间分辨高分辨率（100 nm 以下）显微镜铺平了道路。