Wavefront-corrected high-intensity vortex beams exceeding 10²⁰W/cm²

The use of vortex laser beams has increased in various areas of optics and photonics, necessitating enhanced beam quality for wide usage. In the field of high-power lasers, a range of methods to implement vortex laser beams has been proposed. Nonetheless, enhancing beam quality becomes more challenging as the laser power increases. This study presents the successful implementation of a high-quality, high-intensity vortex laser beam exceeding 1020 W=cm2-an essential advancement for enhancing the performance and applicability of high-power lasers.We achieved this by integrating a spiral phase mirror (SPM) with an orbital angular momentum of l =1, specially designed for the vortex beam, along with an adaptive optical system, into a 150-TWfemtosecond Ti:sapphire laser. Importantly, SPM, featuring a modulation structure to correct for a 45° incidence angle, was utilized to produce the vortex beam. The adaptive optical system, comprising a Shack-Hartmann wavefront sensor and a deformable mirror, employed a feedback loop to correct wavefront aberrations distorting the vortex beam. Notably, the negligible difference between the Hartmanngrams of the Gaussian and vortex beams (l =1) allowed theGaussian beam'sHartmanngram to serve effectively as the input reference for wavefront correction, resulting in a successfully corrected vortex beam wavefront. Experimental results, both preand post-wavefront correction, were compared with simulation results obtained via field-tracing. The peak intensity of the focused high-quality vortex laser beam ultimately reached 1.8×1020 W/cm2, exceeding previously reported experimental results. The results of this study could significantly contribute to the exploration of high-intensity angular momentum transfer in relativistic laser-plasma interactions.