Twisted light gets a splash of colour

A technique that blends micro- and nanometre-scale printed elements has been used to sculpture white light into a spatial array of coloured twisted beams, demonstrating sophisticated photonic control even with common incoherent sources of light.

Light-carrying orbital angular momentum (OAM) has seen an explosion in research activity over the past 30 years^1,2, realising high-dimensional encoding schemes for classical and quantum communication, novel rotational metrology tools, edge enhancement in imaging, and magnified chiral response in light-matter interactions, to name but a few. OAM light is easily produced in the laboratory by tailoring the wavefront to be helical, but this, unfortunately, requires highly coherent laser sources, a severe limitation that has hindered the deployment of OAM for widespread practical applications, such as illumination technology and displays, considering that we typically use incoherent white light sources in everyday life.