Electro-optical nonlinearities in strongly coupled GaAs/AlAs superlattices.

The electric field dependent absorption properties of p-i-n diodes containing GaAs/AlAs superlattices with extremely thin (gleich oder großer als 1nm) AlAs barriers are reported. At low fields, pronounced structures are observed which are due to Stark localization of miniband states. This effect is still present at room temperature and can be used to obtain multistable electro-optical behaviour. At high fields, resonant coupling between different Stark ladders gives rise to a splitting of spectroscopic lines which strongly influences the absorption properties of these superlattices.