Optical Bistability in ZnSe–ZnS Superlattices Optical Waveguide

Abstract

The excitonic optical nonlinearities and optical bistability are observed in ZnSe-ZnS superlattices optical waveguide at room temperature for the first time. The excitonic absorption band is broadened and tends to saturating absorption, and has a blue shift towards short wavelength side with increasing incident intensities. At higher incident intensity, the switching response time of the optical bistability is 500 ps. The results suggest that the optical nonlinearities are due to the phase space filling of excitonic states, excitonic saturating absorption and excitonic band broadening, while the major contribution to the optical bistability is due to increasing absorption effect caused by phase space filling of excitonic states and excitonic band broadening.