Laser pulse creates frequency doubling in amorphous dielectric material

Researchers have demonstrated a new all-optical technique for creating robust second-order nonlinear effects in materials that don't normally support them. Using a laser pulse fired at an array of gold triangles on a titanium dioxide (TiO2) slab, the researchers created excited electrons that briefly doubled the frequency of a beam from a second laser as it bounced off the amorphous TiO2 slab.