2023/11/04 by Nanshun Huang, Huang, Nanshun, Haixiao Deng +1
Physics and Astronomy · #Accelerator Physics (physics.acc-ph) #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Laser-Matter Interactions and Applications #Mechanical and Optical Resonators #Optics (physics.optics)
paper · pdf · doi:10.48550/arxiv.2311.02474
openalex publication_date 2023/11/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
X-ray vortices carrying tunable Orbital Angular Momentum (OAM) are an emerging tool for X-ray characterization technology. However, in contrast to the generation of vortex beams in the visible wavelength region, the generation of X-ray vortices in a controlled manner has proved challenging. Here, we overcome this challenge using an X-ray free-electron laser oscillator (XFELO), which can produce intense coherent X-rays with switchable OAM. Using the pinhole mirror in an XFELO, this scheme adjusts only the kinetic energy of the electron beam to produce vortex beams that can be programmed to dynamically change between different OAM modes without the need for additional optical elements. With the nominal parameters of currently constructing 1 MHz repetition rate facility (i.e. SHINE), the active formation of the OAM modes of l = ±1 and l = ±2 and the rapid switching between them by detuning the electron beam energy of the XFELO are numerically illustrated. The real-time switching can be achieved within 200 μs, while the output pulse energy can reach the 100 μJ level.