Nonlinear optical tuning of a two-dimensional silicon photonic crystal

We use the real (Kerr) and imaginary (two photon absorption) parts of a third order optical nonlinearity to tune the long (1.60.3em0exμm) and short wavelength (1.30.3em0exμm) band edges of a stop gap in a two-dimensional silicon photonic crystal. From pump-probe reflectivity experiments using 1300.3em0exfs pulses, we observe that a 20.3em0exμm pulse induces optical tuning of the 1.30.3em0exμm edge via the Kerr effect whereas a 1.760.3em0exμm pulse induces tuning of the 1.60.3em0exμm band edge via both Kerr and Drude effects with the latter related to two-photon induced generation of free carriers with a lifetime of ~9000.3em0exps.