Optical anisotropy in arrow-shaped InAs quantum dots

We have observed a direct correlation between nonspherical shape and polarization anisotropy of optical transitions in quantum dots. The dots, grown by self-assembling during epitaxial deposition of InAs on $\mathrm{GaAs}\mathrm{}\left(311\right)A,$ exhibit a nonconventional, faceted, arrowheadlike shape aligned in the [2¯33] direction. The dot photoluminescence emission is partially $(\approx 13\%)$ polarized along the same [2¯33] direction. The presence and the sign of the emission polarization is in agreement with the predictions of a theoretical model. Full morphological and optical characterization is reported.