Credit: Image courtesy of Sandia National Laboratories
Artist’s rendering of an incident laser beam (top of the figure) illuminating an array of nanoscale gold resonators on the surface of a “quantum well” semiconductor (slab in figure). (A quantum well is a thin layer that can restrict the movement of electrons to that layer.) The incoming laser beam interacts with the array and the quantum wells and is converted into two new laser beams with different wavelengths. Changing the size, shape, and arrangement of the resonators can be used for beam focusing, beam steering, or control of the beam’s angular momentum.