Using Nano-Optics to Control the Phase of Light

Sometimes, an odd thing happens when you shine light at an array of pinholes smaller than the wavelength of the light. Although you’d expect that very little light would propagate through the holes, at some wavelengths a lot more light is transmitted than can be explained geometrically. This effect is due to interactions between the resonance of the incident light and surface excitations. Now researchers at the University of Florida and elsewhere have discovered a way to manipulate the phase of light using arrays of sub-wavelength slits, while still transmitting more light than expected (Opt. Lett. 33, 1410).