Photocurrent detection of the orbital angular momentum of light

Abstract

Optical vortices on demand Light has several degrees of freedom (wavelength, polarization, pulse length, and so on) that can be used to encode information. A light beam or pulse can also be structured to have the property of orbital angular momentum, becoming a vortex. Because the winding number of the vortex can be arbitrary, the channel capacity can be expanded considerably. Zhang et al. and Ji et al. developed nanophotonic-based methods for generating and electrically detecting light with arbitrary orbital angular momentum, a goal that has remained an outstanding challenge so far (see the Perspective by Ge). The nanophotonic platform provides a route for developing high-capacity optical chips. Science , this issue p. 760 , p. 763 ; see also p. 707