Intersubband optical absorption in heavily dopedn-type GaAs/Al0.3Ga0.7As multiple quantum wells

Abstract
Intersubband optical absorption between the ground and first excited states and the first and second excited states is reported for n-type doped GaAs/Al1x GaxAs multiple quantum wells. This phenomenon is shown to be due to high doping, which causes more than one subband to be populated. Experimental results supported by theoretical calculations are presented.