Optical switching in hybrid semiconductor nonlinear photonic crystal slabs with Kerrmaterials

Abstract

Nonlinear photonic crystals, whose refractive index distribution can be tunedoptically, have been used to demonstrate all-optical switching due to a change of therefractive index and subsequent shift of the bandgap edge or the defect stateresonant frequency. Semiconductor-based all-optical switching is still limited bythe weak nonlinearity and the slow response time owing to the slow dynamicsof two-photon-generated free carriers. Here we introduce a concept of hybridnonlinear photonic crystals that are made from infiltrating the air-hole arrayor coating the surface of the usual semiconductor photonic crystal slabs withorganic polystyrene materials. The hybrid configuration can help to realize very fastresponse speeds and strong nonlinearity in the semiconductor-based device. We studythe influence of the thickness of the polystyrene film on the gap shift scale, andalso analyze its physical mechanism. The switching effect on this structure wasdiscussed, and shows that the nonlinear hybrid structure can achieve relatively largertransmission contrast. Our result may be helpful in designing integrated opticalcircuits.