Polarimetry-based analysis of dipolar transitions of single colloidal   CdSe/CdS dot-in-rods
  We prove experimentally, upon polarization analysis performed on a large statistic of single nanoemitters, that high quality core/shell CdSe/CdS dot-in-rods behave as linear dipoles. Moreover, the dipole in-plane and out-of-plane orientations could be assessed. We demonstrate in particular that, contrary to expectations, the emitting dipole is not aligned with the elongated axis of the dot-in-rod. Besides, the polarimetric measurements prove that the excitation transition cannot be approximated by a single linear dipole, contrary to the emission transition. Finally, we highlight that non-radiative channels of charge carrier recombination do not affect the dipolar nature of the radiative transitions. 
Clotilde Lethiec, Ferruccio Pisanello, Luigi Carbone, Alberto Bramati,   Laurent Coolen and Agn\`es Ma\^itre
physics.optics