Improvement in intersubband optical absorption and the effects of device parameter variations in quantum wells with an applied electric field

The intersubband optical absorption in symmetric and asymmetric, single and coupled, double GaAs/Ga1-xAlxAs quantum wells is calculated. The results h ave been obtained in the presence of a uniform electric field as a function of the potential symmetry, size of the quantum well, and coupling paramete r of the wells. In coupled double quantum wells we obtain a large Stark eff ect that can be used to fabricate tuneable photodetectors. We show that the effect of an applied electric field on the intersubband optical absorption is similar to changes in the dimensions of the structure. This behaviour i n the intersubband optical absorption for different wells and barrier geome tries can be used to study these systems in regions of interest, without th e need for the growth of many different samples. (C) 1999 Academic Press.