Arbitrary topological charge vortex beams from carbon dots random lasers

Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication, optical micromanipulation, and quantum information processing. Here, we demonstrate vortex beams with flexible control of the topological charge and modes in a carbon dots random laser for the first time. Vortex beams with different types, including the Laguerre–Gaussian (LG), Bessel–Gaussian (BG), LG-superposition, and polarized vortex beams with topological charges up to 50, have been successfully achieved. Moreover, vortex beams can be well realized in carbon dots random lasers with different emission wavelengths covering from 465 to 612 nm. This work would not only enrich the types of vortex laser, especially for solution-processable lasers, but also provide a new route to realizing multi-color and wavelength-tunable vortex lasers.