Intersubband absorption modulation in coupled double quantum wells by external bias

The scope for using intersubband absorption for electroabsorption modulation has been investigated by a detailed self-consistent solution of the coupled Schrodinger-Poisson equations. Rapid changes in intersubband absorption coefficient with electric field are predicted for modulation-doped In0.53Ga0.47As/AlAs deep coupled quantum wells arising from a combination of Stark effect, field-induced changes in the optical matrix elements and quantum well occupancy. Extensive simulations reveal that controlling the density of electrons in the quantum wells is potentially the most robust process for prospective high-speed modulation by intersubband electroabsorption.