Multistable spatial solitons in semiconductor resonators

Direct semiconductors, as e.g. AlGaAs, exhibit huge nonlinearities for phot on energies slightly below the fundamental band edge. We show that in this domain persistent bright solitary waves can emerge in a planar resonator. T heir existence could pave the way towards an highly parallel all-optical in formation processing and storage scheme. The formation of solitary waves is primarily due to saturation of a defocusing nonlinearity, diffusion and in duced absorption. Saturation is evoked by prominent many-particle effects l ike screening and band filling whereas the induced absorption stems from th e gap renormalization. It turns out that solitary waves of different topolo gy may exist for the same detuning, thus representing a kind of multistabil ity. (C) 1999 Elsevier Science Ltd. All rights reserved.