Short-wavelength intersubband absorption in strain compensated InGaAs/AlAs quantum well structures grown on InP

We report a X-ray diffraction and Fourier transform infrared spectroscopy study of highly strain compensated InxGa1-xAs/AlAs/ InyAl1-yAs multiple quantum well structures grown pseudomorphically grown on InP substrate by gas-source molecular beam epitaxy. X-ray diffraction patterns show compositional grading of the interfaces that markedly influence the absorption spectra. The intersubband transitions at wavelengths shorter than 2.0 mm for QW structures with different InGaAs well thickness are presented.