In this paper, nonlinear Thomson scattering in an intense () tightly focused () Gaussian laser pulse is theoretically and numerically investigated to demonstrate varying spatial characteristics in the few-cycle and multi-cycle domains. We find that within ultrashort incident laser pulses, electrons have the potential to radiate a single attosecond pulse with a large signal-to-noise ratio, which turns into a train of attosecond pulses with a multi-cycle laser. Furthermore, a novel asymmetry phenomenon is discovered for the first time in the few-cycle domain whereby spatial radiation lasts for only one circle with apparent peaks and valleys, in contrast to the helical radiation pattern apparent in the multi-cycle domain, which gradually turns into a common fourfold-symmetry pattern. This means that the difference between tightly and non-tightly focused laser pulses can be bridged utilizing an appropriate incident pulse duration under specific conditions. The above difference is demonstrated again in the polar plane, where electrons change from a light-spot to a light-band radiation feature when the incident pulse duration increases.

在本文中，在强（）紧聚焦（对高斯激光脉冲进行了理论和数值研究，以证明在几个周期和多个周期域中变化的空间特征。我们发现，在超短入射激光脉冲中，电子有可能辐射出具有大信噪比的单个阿秒脉冲，而在多周期激光的作用下，电子会变成一系列的阿秒脉冲。此外，在多周期域中首次发现一种新颖的不对称现象，从而空间辐射仅持续一个带有明显峰谷的圆，这与在多周期域中逐渐旋转的螺旋辐射图相反。变成常见的四重对称模式。这意味着在特定条件下，可以使用适当的入射脉冲持续时间来弥合紧密聚焦激光脉冲和非紧密聚焦激光脉冲之间的差异。在极平面中再次证明了上述差异，在极平面中，当入射脉冲持续时间增加时，电子从光斑变为光带辐射特征。