Direct Transfer of Light’s Orbital Angular Momentum onto a Nonresonantly Excited Polariton Superfluid

Recently, exciton-polaritons were found to condense into a coherent ground state much like a Bose-Einstein condensate and superfluid. They have become a good testbed for generating and manipulating quantum vortices in a dissipate-driven superfund by the optical control of light-matter coupling inside a semiconductor microcavity. Here, we generate exciton-polariton condensate with non-resonant Laguerre Gaussian (LG) optical beam and verify the direct transfer of light's orbital angular momentum to exciton-polariton quantum fluid. Quantized vortices are found in spite of large energy relaxation involved in non-resonant pumping. We identified phase singularity, density distribution and energy eigenstates for the vortex states. Our observations confirm that non-resonant optical LG beam can be used to manipulate chirality, topological charge and stability of non-equilibrium quantum fluid. It suggests that quantum information can be transferred between photon and exciton-polariton relatively easily, and they can be expanded to form the controllable network of multiple topological charges even in the presence of solid state spectral randomness.