Manipulating the orbital angular momentum of light at the micron scale with nematic disclinations in a liquid crystal film.

We report on the experimental manipulation of the orbital angular momentum of light by exploiting a kind of topological defects that spontaneously appear in nematics-disclinations-as microscopic optical spin-orbit interfaces whose operating wavelength can be controlled electrically. Using six different kinds of disclinations, we demonstrate the efficient generation of both scalar and vectorial singular light beams with a broad topological diversity from a fundamental Gaussian beam.