Optical switching in hybrid semiconductor nonlinear photonic crystal slabs with Kerr materials

Nonlinear photonic crystals, whose refractive index distribution can be tuned optically, have been used to demonstrate all-optical switching due to a change of the refractive index and subsequent shift of the bandgap edge or the defect state resonant frequency. Semiconductor-based all-optical switching is still limited by the weak nonlinearity and the slow response time owing to the slow dynamics of two-photon-generated free carriers. Here we introduce a concept of hybrid nonlinear photonic crystals that are made from infiltrating the air-hole array or coating the surface of the usual semiconductor photonic crystal slabs with organic polystyrene materials. The hybrid configuration can help to realize very fast response speeds and strong nonlinearity in the semiconductor-based device. We study the influence of the thickness of the polystyrene film on the gap shift scale, and also analyze its physical mechanism. The switching effect on this structure was discussed, and shows that the nonlinear hybrid structure can achieve relatively larger transmission contrast. Our result may be helpful in designing integrated optical circuits.