OPTICAL ANISOTROPY IN ARROW-SHAPED INAS QUANTUM DOTS

We have observed a direct correlation between nonspherical shape and p olarization anisotropy of optical transitions in quantum dots. The dot s, grown by self-assembling during epitaxial deposition of InAs on GaA s(311)A, exhibit a nonconventional, faceted, arrowheadlike shape align ed in the [(2) over bar 33] direction. The dot photoluminescence emiss ion is partially (approximate to 13%) polarized along the same [(2) ov er bar 33] direction. The presence and the sign of the emission polari zation is in agreement with the predictions of a theoretical model. Fu ll morphological and optical characterization is reported.