Strain-induced optical anisotropy in self-organized quantum structures at the E-1 transition

In-plane optical anisotropies of (001)-oriented InAs/InP self-assembled qua ntum wires and dots structures are studied by means of photoreflectance in the spectral region of the E-1 transition of bulk InAs. The energy position of the transition observed in the quantum wires depends on the light polar ization; quantum dots do not exhibit, in contrast, such an optical anisotro py. This anisotropy is attributed to the splitting of the four-fold degener ate E-1 transition produced by the strong triaxial behavior of the strain t hat appears in wires and not in dots. (C) 2000 American Institute of Physic s. [S0003-6951(00)00616-1].