X(2) semiconductor photonic crystals

Playing a central role in microelectronics and optoelectronics, semiconductors almost stand apart from applications involving second-order nonlinear effects such as frequency converters, tunable sources, parametric amplifiers, and switches. The reasons are twofold: their strong chromatic dispersion, which prevents the interacting waves from propagating with the same phase velocity (phase mismatch), and the shortness of the semiconductor devices, which adds more difficulty to achieving reasonable nonlinear efficiencies. By exploiting the unique properties of photonic crystals, we demonstrate simultaneous phase matching and enhancement of the fields under nonlinear interaction. We demonstrate a second-harmonic efficiency growth faster than the fifth power of the structure length. (C) 2002 Optical Society of America.