Room-temperature excitonic optical bistability in a GaAs-GaAlAs superlattice étalon

The quantum wells provided by a superlattice increase the binding energy of the free excitons in GaAs, permitting 300 K bistable operation of a superlattice etalon. The superlattice consists of 61 periods of 336 Å GaAs and 401 Å Ga0.73Al0.27As. The intensities required are about 1 mW/ ( μm)2 and the switching times are 20–40 ns, similar to the low-temperature pure GaAs values. Room-temperature operation of semiconductor etalons enhances the likelihood of all-optical logic and switching.