Optical bistability with 100 ps switching time has been observed in ZnS/ZnSe stratified grating filter at room temperature for the first time. We think that the optical bistability results from the band-filling effect caused by the nonlinear absorption of the material and reflection occurred among the multilayer films. When the light intensity is larger enough. The refractive index change will be larger and the transmitted light intensity increases remarkably owing to the third order nonlinear effect of ZnS/ZnSe, so ZnS/ZnSe stratified grating is of optical bistability.
We present results of transmittance measurements on periodic layers of ZrO<SUB>2</SUB>/SiO<SUB>2</SUB> at optical frequencies. These one- dimensional photonic band gap materials exhibit transparency bands and a huge stop band at optical frequencies. A unique feature of these dielectric/dielectric photonic band gap (MM- PBG) materials is that the overall reflectance in the stop band may increase as more periods are deposited. The center frequency and width of the stop bands are adjustable and generally depend on the thickness of the layers and the number of ZrO<SUB>2</SUB>/SiO<SUB>2</SUB> periods. These simple periodic structures have applications as microcavity reflector in microcavity lasers.