Comparaison of the Optical Anisotropy of Corrugated and NonCorrugated (311) Superlattices

We report the electronic and optical properties of corrugated and non-corrugated (311) (GaAs)/(AlAs) superlattices using the tight-binding method. These systems grown by molecular beam epitaxy on (311) GaAs oriented substrates. We present the valence and conduction band dispersion relations (band structures) for the corrugated (311) (GaAs)16/(AlAs)16 superlattice. We have studied the probability densities of the lowest conduction band and highest valence band interband transition probabilities of the non-corrugated (311) (GaAs)8/(AlAs)8 superlattice and the corrugated (311) (GaAs)16/(AlAs)16 superlattice. We have also computed the interband transition probabilities for these systems. We found that the anisotropy rate of the interband transitions for the corrugated superlattice is larger than for the non-corrugated superlattice one. We concluded that whatever the type of superlattice studied here, the optical anisotropy is reduced when the light polarization pass from the [-2,3,3] direction to [0,-1,1] direction for the transitions from the heavy-hole-like states. The opposite situation occurs for the transition from the light-hole and split-off-like states.