Enhancement of nonlinear optical effect in one-dimensional photonic crystal structures

We observed the photonic band structure of one-dimensional photonic crystal s using a white-light Michelson interferometer. fn one-dimensional photonic crystals with a structural defect, there is a localized mode where the fie ld is localized around the position of the defect. If the defect is made of nonlinear optical material, the effective nonlinearity of the photonic cry stal is largely enhanced by the enhanced light intensity at the defect. In a one-dimensional photonic crystal with a defect, we observed a large enhan cement of degenerate four-wave mixing efficiency. Since the total thickness of the whole structure is only a few micrometers, it was successfully used to form an optical phase-conjugated image.