Twisted light on a chip

Compact devices provide new ways to generate and detect optical vortex beams A large-scale vortex is an extraordinary phenomenon to behold, be it a hurricane in the North Atlantic Ocean or the Great Red Spot on Jupiter. A vortex on a small scale is equally fascinating, especially when its quantum nature starts to emerge. Alexei Abrikosov won a Nobel Prize by introducing vortices in a phenomenological model to describe a new type of superconductor in 1950s ( 1 ), which turned out to be a feature of paired electrons in supercurrent. A very different type of vortex can be created for light ( 2 ). On pages 760 and 763 of this issue, Zhang et al. ( 3 ) and Ji et al. ( 4 ) demonstrate new ways to generate and detect such optical vortex beams on a tiny semiconductor chip.