SHORT-WAVELENGTH INTERSUBBAND TRANSITIONS IN INGAAS ALGAAS QUANTUM-WELLS GROWN ON GAAS/

We have demonstrated intersubband transition energies as high as 580 m eV (2.1 mu m 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/AlA s QWs have been determined. Good agreement of the intersubband transit ion energies to a single band effective mass model with band nonparabo licity included is found. Experimental studies of buffer and QW growth parameters for optimized intersubband absorption have also been perfo rmed.