Channeling light without complex waveguidesWhen a stone is dropped into water, circular waves spread outward from the point of impact. Light behaves similarly: when emitted from a localized source, it naturally propagates as spherical or circular wavefronts within a material. Similarly, photonic integrated circuits rely on nanoscale waveguides fabricated by complex lithographic processes, including resist coating, lithography, and etching. By placing a nanoscale gold antenna on the surface and illuminating it with infrared laser light, they generated highly confined optical waves that propagated exclusively along a single direction. Instead, its intrinsic crystal properties determine the direction of light propagation.