The basic physics of nonlinear optics in semiconductors is reviewed. O
ptical bistability due to increasing absorption and in a Kerr cavity i
s discussed, as are spatial solitons in a Kerr medium. These introduce
recent research on spontaneous pattern formation and soliton-like str
uctures in semiconductor cavity models. Applications to optical inform
ation processing are discussed, and simulations of a soliton array mem
ory presented.