Analysis of pulse width on the spatial properties of electron motion and radiation driven by linearly polarized tightly focused chirped laser pulses

This study investigates the relationship between electron trajectories, spatial radiation characteristics, and laser parameters (pulse width and chirp) under linearly polarized tightly focused chirped laser pulses through numerical simulations and theoretical analysis. Our findings demonstrate that the chirp parameter significantly influences electron kinematics—negative chirp produces more compact electron trajectories. Furthermore, increasing pulse width expands the spatial range of electron motion while reducing radiation collimation. The research also reveals that chirp modulation broadens the radiation spectrum and enhances peak power, with negative chirp exhibiting superior performance in generating high-frequency harmonics. These results provide important theoretical insights for optimizing ultrashort-pulse X-ray radiation sources in applications such as medical imaging and ultrafast dynamics research.