标题： 时空非可分螺旋脉冲的观测 显示英文标题

标题： Observation of space-time nonseparable helical pulses

摘要： 在超快时空耦合领域操控光学涡旋仍然是光子学中的一个重大挑战。 特别是，携带稳定涡旋拓扑电荷的单周期或少数周期短脉冲，称为螺旋脉冲，尚未被实验实现。 在这里，我们介绍了两种互补的方法，在光学和微波光谱范围内实验生成这种时空不可分离的螺旋脉冲（SNHPs）。 我们通过光学环面脉冲的偏振分解实现了少周期准线性偏振的 SNHPs。 我们还直接从微波超宽带螺旋发射器生成了精确的单周期非横向 SNHPs。 这些方法不仅实现了 SNHPs 的实验生成，还为进一步研究其性质和应用（如非平凡的光-物质相互作用和光通信）提供了平台，标志着结构光领域的重要进展。 显示英文摘要

摘要： Manipulating optical vortices at ultrafast spatiotemporal coupled domain is still a great challenge in photonics. Especially, the single- or few-cycle level short pulses carrying stable vortex topological charge, called helical pulses, have never been experimentally realized. Here, we introduce two complementary methods for experimentally generating such space-time nonseparable helical pulses (SNHPs) across optical and microwave spectral regimes. We achieve few-cycle quasi-linearly polarized SNHPs through the polarization decomposition of optical toroidal pulses. We also generated exactly single-cycle nontransverse SNHPs directly from a microwave ultrawideband spiral emitter. These approaches not only enable the experimental realization of SNHPs but also provide a platform for further investigation into their properties and applications, such as nontrivial light-matter interactions and optical communications, marking a significant step forward in the field of structured light.