Ultra-intense high-order-mode vortex laser generation via axial line-focused pinhole plates

Relativistic vortex laser generation has recently emerged as a focal point in the field of laser-plasma interaction. However, most studies have primarily focused on generating vortex lasers with topological charge |<i>l</i>| ≤ 3, leaving a significant gap in the generation of high-order modes (|<i>l</i>| ≥ 4) relativistic vortex lasers with high mode purity. In this study, we propose a novel scheme employing axial line-focused pinhole plates (ALPP) to generate ultra-intense high-order-mode vortex lasers with high mode purity. Three-dimensional particle-in-cell simulation results demonstrate that the ALPP targets can effectively modulate the topological charge of the incident laser within a tunable focal volume to generate ultra-intense vortex lasers with topological charge |<i>l</i>| ≥ 4, intensity exceeding 10²¹ W/cm², and a dominant mode weight of over 60<i>%</i>. The output vortex laser can interact with a wire plasma target to generate energetic electron beams with a helical topological structure in space. This scheme provides a feasible way for generating high-quality high-order-mode relativistic vortex lasers, potentially expanding the scope of relativistic vortex laser-plasma interactions research and holding promise for applications in generating high-angular momentum particle beams and ultra-intense magnetic fields.