Anisotropic Optical Transitions in [110]-Oriented Semiconductor Quantum Well Studied by Photoreflectance Spectroscopy

We have experimentally investigated optical anisotropy in [110]-oriented multiple quantum well, which is considered to be an important structure for novel quantum devices. By employing polarized photoreflectance spectroscopy, the anisotropies of in-plane optical transition matrix element were clearly observed for higher-order interband transitions as well as the band-edge transition. The degree of polarization depends on the quantum-well width and the order of quantum level related to the transition. The experimental results qualitatively agree with those of a numerical calculation based on the Luttinger–Kohn Hamiltonian.