Short wavelength intersubband transitions in InGaAs/AlGaAs quantum wells grown on GaAs

Abstract
We have demonstrated intersubband transition energies as high as 580 meV (2.1 μm wavelength) in InGaAs/AlGaAs quantum wells (QWs) grown on GaAs substrates. The well width dependence of intersubband transition energies in both In0.5Ga0.5As/Al0.45Ga0.55As QWs and In0.5Ga0.5As/AlAs QWs have been determined. Good agreement of the intersubband transition energies to a single band effective mass model with band nonparabolicity included is found. Experimental studies of buffer and QW growth parameters for optimized intersubband absorption have also been performed.