Proton acceleration driven by relativistic femtosecond Laguerre–Gaussian lasers

With the advancement of ultra-intense and ultra-short laser technology, lasers have achieved new parameters in femtosecond (10^–15 s) and petawatt (10¹⁵ W) ranges. Ion acceleration driven by these lasers has become a prominent research area. However, most research still relies on traditional Gaussian lasers, posing challenges in enhancing the low divergence angle, high flux, and high collimation of ion beams. This paper reviews a novel laser mode—the Laguerre–Gaussian (LG) laser in the relativistic domain. LG lasers feature a hollow intensity distribution and angular momentum, offering centripetal force and phase modulation at the axis center, reducing particle beam divergence and enabling focused acceleration. High-quality proton beams driven by ultra-intense, ultra-short LG lasers have promising applications in proton therapy, fast ignition in inertial confinement fusion, proton imaging, particle injection in accelerators, and astrophysics.