High purity twisted light from a metasurface solid state resonator

Twisted light carrying orbital angular momentum (OAM) has given rise to many developments ranging from optical manipulation to optical communications. Generating twisted light from solid-state lasers was initially achieved by amplitude and dynamic phase control, and more recently by manipulating the geometric phase of light. These lasers have been limited to generate superposition of OAM modes as well as scalar modes with OAM e = 10. Here we incorporate a metasurface device into a visible solid-state laser to control the angular momentum of light by arbitrary spin-to-orbit coupling. We demonstrate the generation of pure Laguerre Gaussian modes with OAM up to e = 100. Modal decomposition measurements of the output beams reveal the higher purity of the generated modes can reach up to 96% for e = 1 and 88% for e = 100. our approach offers a new route for high brightness OAM states at the source.