Электронный каталог

Статья

Dyatlov, A.S.
Generation of High-OAM Ultraviolet Twisted Light for RF-Photoinjector Applications / A.S.Dyatlov, V.V.Kobets, M.A.Nozdrin, V.I.Shokin, K.E.Yunenko, [a.o.]. – Text : electronic // Optics Communications. – 2026. – Vol. 617. – P. 133388. – URL: https://doi.org/10.1016/j.optcom.2026.133388. – Bibliogr.: 54.

The generation of relativistic vortex electron beams via photoemission requires ultraviolet (UV) laser beams with well-controlled orbital angular momentum (OAM) compatible with radio-frequency (RF) photoinjector drive-laser systems. However, achieving high-OAM beam generation in the deep UV with sufficient efficiency, stability, and mode control remains technically challenging. Here, we experimentally demonstrate the generation of high-OAM (up to ℓ=64⁢ħ) UV vortex beams at 266 nm using three types of fabricated diffractive optical elements integrated into an operational photoinjector drive-laser system: a reflective fork grating, a high-topological-charge spiral phase plate, and binary axicons. The spiral phase plate produces a high-purity Laguerre–Gaussian mode with a conversion efficiency of 80%, while fork gratings provide flexible access to lower-order OAM states and enable robust modal diagnostics. In contrast, binary axicons generate low-divergence quasi-Bessel beams that can be interpreted as controlled superpositions of multiple OAM states with a finite OAM bandwidth. The generated beams are characterized using cylindrical-lens mode conversion and radial intensity analysis, demonstrating controlled generation of both near-pure OAM eigenstates and broadband OAM distributions in the UV regime. These results provide a comparative, application-driven framework for selecting UV-compatible OAM generation techniques and establish a practical route toward structured photocathode illumination in high-brightness RF photoinjectors.



Спец.(статьи,препринты) = С 345 о - Электронная и ионная оптика. Формирование и анализ пучков
ОИЯИ = ОИЯИ (JINR)2026