A tunable ultrafast intensity-rotating optical field is generated by overlapping a pair of 20 Hz, 800 nm chirped pulses with a Michelson interferometer (MI). Its rotating rate can be up to 10 trillion radians per second ( $\text{Trad}/\text{s}$ ), which can be flexibly tuned with a mirror in the MI. Besides, its fold rotational symmetry structure is also changeable by controlling the difference from the topological charges of the pulse pair. Experimentally, we have successfully developed a two-petal lattice with a tunable rotating speed from $3.9~\text{Trad}/\text{s}$ up to $11.9~\text{Trad}/\text{s}$ , which is confirmed by our single-shot ultrafast frame imager based on noncollinear optical-parametric amplification with its highest frame rate of 15 trillion frames per second (Tfps). This work is carried out at a low repetition rate. Therefore, it can be applied at relativistic, even ultrarelativistic, intensities, which usually operate in low repetition rate ultrashort and ultraintense laser systems. We believe that it may have application in laser-plasma-based accelerators, strong terahertz radiations and celestial phenomena.

中文翻译：

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周期低至飞秒区域的可调谐超快强度旋转光场的生成和成像

通过将一对 20 Hz、800 nm 啁啾脉冲与迈克尔逊干涉仪 (MI) 重叠，可生成可调谐的超快强度旋转光场。它的旋转速度可以达到每秒10万亿弧度（ $\text{繁体}/\text{s}$ )，可以通过 MI 中的镜像灵活调整。此外，它的折叠旋转对称结构也可以通过控制与脉冲对拓扑电荷的差异来改变。通过实验，我们成功地开发了一种具有可调转速的双花瓣晶格，从 $3.9~\text{繁体}/\text{s}$ 取决于 $11.9~\text{繁体}/\text{s}$ ，我们基于非共线光学参数放大的单次超快帧成像仪证实了这一点，其最高帧速率为每秒 15 万亿帧 (Tfps)。这项工作以低重复率进行。因此，它可以应用于相对论甚至超相对论的强度，这些强度通常在低重复率的超短和超强激光系统中运行。我们相信它可能在基于激光等离子体的加速器、强太赫兹辐射和天体现象中得到应用。