Nonlinear Optical Response of 1-D Photonic Crystals Fabricated by Using a Sol-Gel Method

Abstract

The picosecond nonlinear optical response in .ve-bilayered SiO2/TiO2 structures of one- dimensional photonic crystals fabricated by using a sol-gel method is reported. We observe nonlin- ear optical changes in the transmission at both bandgap edges, an 8 % decrease at the high-energy edge, and a 4:5 % increase at the low-energy edge. These changes correspond to a blue shift of the bandgap. The observed reponse originates from the optical nonlinearity of the TiO2 layer.