Photons possess a number of quantum properties that can be used to encode information. You can think of photon polarization as like the rotation of a planet on its axis. In this view, the helical shape of the light wave—known as its orbital angular momentum (OAM)—is akin to the planet’s orbit around the Sun. These properties are independent of each other, and of the wavelength of light, so they can be manipulated separately. Whereas polarization occurs as a combination of two possible orientations, the OAM theoretically can have infinite values, though in practice far fewer states are available. Nevertheless, exploiting OAM greatly expands the potentially exploitable quantum states of photons we could put to use.

via Fabbing a chip that could encode data in a twisted vortex of light | Ars Technica.