(color online) Three-dimensional polar plots of transition dipole moments of different states of ground state exciton for different magnitudes of LH–HH mixing with in a QD. The sum represents the total oscillator strength of . In the case of , the state is always dark for any value of . The state becomes bright with the direction of polarization along the growth direction of the QD for a nonzero value of the LH character in the hole states. The intensity of this state increases with an increase in the LH character. The and states are equally bright with directions of polarization in the growth-plane of the QD. However, for the case of mixed HH-LH hole states the intensity of decreases, while that of increases with an increase in LH character. Eventually the becomes dark for about 75% LH character in the hole state. For further increase in LH character the becomes bright again. For pure LH the and are equally bright with the directions of polarization normal to each other in the growth-plane, while is strongly bright with the direction of polarization along the growth direction of the QD.