Generation of correlated photons in hydrogenated amorphous-silicon waveguides

We report the first (to our knowledge) observation of correlated photon emission in hydrogenated amorphous-silicon waveguides. We compare this to photon generation in crystalline silicon waveguides with the same geometry. In particular, we show that amorphous silicon has a higher nonlinearity and competes with crystalline silicon in spite of higher loss. (C) 2010 Optical Society of America