With the development of ultra-intense laser technology, MeV ions can be obtained from laser–foil interactions in the laboratory. These energetic ion beams can be applied in fast ignition for inertial confinement fusion, medical therapy, and proton imaging. However, these ions are mainly accelerated in the laser propagation direction. Ion acceleration in an azimuthal orientation was scarcely studied.

Researchers at Shanghai Institute of Optics and Fines Mechanics (SIOM/China) used a doughnut Laguerre–Gaussian (LG) laser for the first time to examine laser–plasma interaction in the relativistic intensity regime in three-dimensional particle-in-cell simulations[ Scientific Reports.5:8274(2015)].

Studies had shown that a novel rotation of the plasma was produced from the hollow screw-like drill of an LG10 mode laser.The angular momentum of particles in the longitudinal direction produced by the LG laser was enhanced compared with that produced by the usual laser pulses, such as linearly and circularly polarized Gaussian pulses. Moreover, the particles (including electrons and ions) could be trapped and uniformly compressed in the dark central minimum of the doughnut LG pulse. The hollow-structured LG laser had potential applications in the generation of x-rays with orbital angular momentum, plasma accelerators, fast ignition for inertial confinement fusion, and pulsars in the astrophysical environment.