Generation of electromagnetic solitons with angular momentum.

The optical vortex has been widely studied owing to its specific characteristics such as the orbital angular momentum, hollow intensity distribution, and topological charge. We report the generation of electromagnetic solitons with angular momentum and the conversion of angular momentum via a circularly polarized (CP) laser and underdense plasma interactions on the basis of three-dimensional particle-in-cell simulations. We find that when a CP laser is incident into the underdense plasma, a longitudinal current will be induced off the laser axis, which is critical for the angular momentum conversion. This novel, to the best of our knowledge, regime will allow potential applications such as optical control and electron manipulation.