On-chip noninterference angular momentum multiplexing of broadband light

Abstract

A twist on optical multiplexing Information can be encoded using various properties of light. Optical multiplexing frequency, brightness, and polarization have played crucial roles in information technologies, high-capacity data storage, high-speed communications, and biological sensing. Angular momentum is another degree of freedom that could increase capacity further. Typically, however, the bulk optical elements used to determine the angular momentum of light limit possible on-chip processing. Ren et al. take a nanophotonics approach to measure and sort light co-propagating with different states of angular momentum (see the Perspective by Molina-Terriza). The approach is promising for on-chip multiplex processing of optical signals. Science , this issue p. 805 ; see also p. 774