Ultrafast time-resolved spectroscopy of one-dimensional metal-dielectric photonic crystals

We study the all-optical switching behavior of one-dimensional metal-dielectric photonic crystals due to the nonlinearity induced by a hot electron gas. A polychromatic pump-probe setup is used to determine the wavelength and pump intensity dependence of the ultrafast transmission suppression as well as the dynamics of the process on a subpicosecond time scale. We find ultrafast (subpicosecond) as well as a slow (millisecond) behavior. We present a model of the ultrafast dynamics and nonlinear response, which can fit the measured data well and allows us to separate the thermal and the electronic response of the system.