Theory turns to reality for nonlinear optical metamaterials (w/video)

A research team has realized one of the long-standing theoretical predictions in nonlinear optical metamaterials: creation of a nonlinear material that has opposite refractive indices at the fundamental and harmonic frequencies of light. Such a material, which doesn't exist naturally, had been predicted for nearly a decade.

Observation of 'backward phase matching' -- a phenomenon also known as the 'nonlinear mirror' -- provided proof that this new type of metamaterial had been created. Demonstration of the phenomenon was reported by researchers at the Georgia Institute of Technology in a paper published June 15 in the journal Nature Materials ("Backward phase-matching for nonlinear optical generation in negative-index materials").