Ultrafast intersubband transitions in InGaAs/AlAs coupled double quantum well structures for near-infrared all-optical switching

We propose in this paper a coupled double quantum well (C-DQW) structure which enables intersubband transition (ISBT) responses useful for near-infrared ultrafast all-optical switching and ultrashort optical pulse emission. We show the capability of all-optical absorption and gain-switching between two ISBT wavelengths which can be tuned down to 1.5 /spl mu/m in InGaAs-AlAs DQW on GaAs substrates.