Low divergence and high energetic proton acceleration with vortex lasers*

Exotic laser beams, carrying angular momentum, can give rise to novel physics in high-intensity laser-plasma interactions [1,2]. The angular momentum leads to a new degree of freedom, yielding from angular momentum transfer and complex non-linear optical processes. Various applications ranging from laser-driven particle accelerators to high-energy-density physics and medical applications can benefit from using exotic laser beams [3,4]. 

We have demonstrated ultra-low divergence (≲ 0.04) proton beams with enhanced proton energies (multi-10-MeV) through the interaction of a laser with orbital angular momentum (OAM) with a double-layer target, relying on three-dimensional particle-in-cell simulations in OSIRIS. We have investigated the reduced relativistic self-focusing [1] of a laser with OAM in near-critical plasmas and determined its crucial role in generating high-quality proton beams.

Lastly, we studied the angular momentum transfer of exotic lasers in underdense plasmas for intense magnetic field generation through the inverse Faraday effect [2]. 

[1] L. Sa and J. Vieira, Phys. Rev. A 100, 013836 (2019).

[2] S. Ali et al., Phys. Rev. Lett. 105, 035001 (2010).

[3] J. Vieira et al., Phys. Rev. Lett. 117, 265001 (2016). 

[4] C. Willim et al., Phys. Rev. Research 5, 023083 (2023).