Kerr and free-carrier ultrafast all-optical switching of GaAs/AlAs   nanostructures near the three-photon edge of GaAs
  We performed non-degenerate pump-probe experiments on a GaAs/AlAs photonic structure. We switched the photonic properties using the optical Kerr effect and free carriers excited by three photon absorption. From these measurements we extracted the non-degenerate Kerr coefficients over a broad wavelength range and we extracted the three photon absorption coefficient for GaAs at three wavelengths in the near infrared. We show that the optical Kerr effect is large enough to switch a cavity resonance with a high \emph{Q} ($Q>1000$) photonic cavity. 
Alex Hartsuiker, Philip J. Harding, Yoanna-Reine Nowicki-Bringuier,   Jean-Michel G\'erard, Willem L. Vos