Ground-state orbital angular momentum lasing from liquid crystal torons embedded in a microcavity

Orbital angular momentum laser beams have many important practical applications, such as optical tweezers or ultrafast communications. Creating such beams represents an important challenge in photonics. Here, we demonstrate that torons, which are topological defects in liquid crystal textures, when embedded in a microcavity, generate a real-space non-Abelian gauge field responsible for the topological inversion of ground and excited states. The resulting ground state produces robust lasing with nonzero orbital angular momentum in each of the circular polarization components.