Electro-optical multistability in GaAs/AlAs superlattices at room temperature.

We have studied the optical absorption properties of a GaAs/AlAs short-period superlattice at room temperature in an electric field perpendicular to the layers. Several pronounced optical transitions related to Wannier-Stark localization are observed indicating a choherence length of at least five superlattice periods. These transitions produce multiple regions of negative differential photoconductivity which are used to realize a multistable self-electro-optic effect device.