Theory of optical bistability in a non-linear quasi-waveguide

Optical bistable behavior in a quasi-waveguide containing non-linear film has been experimentally investigated in several publications in the past years; however, the physical mechanism for optical bistability has not been theoretically explained. In the present letter, we propose a theoretical model and successfully explain the observed optical bistability of both the reflected light and the scattered light (m-lines) in a non-linear quasi-waveguide. The optical bistability in the non-linear quasi-waveguide is due to the scattering-type wavevector mismatch mechanism.