Control of optical polarization anisotropy in edge emitting luminescence of InAs/GaAs self-assembled quantum dots

We have studied the polarization properties of cleaved-edge photoluminescence (PL) from InAs/GaAs self-assembled quantum dots. Transverse-electric (TE) and transverse-magnetic (TM) mode PL intensities have been analyzed for the dots having 8 nm ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{As}$ capping layer with indium (In) composition of $\text{x=0}$ and 0.13. Polarization results show a dramatic change with the capping layer In compositions; TE-mode dominant PL is observed for dots with $\text{x=0,}$ on the other hand, TM-mode dominant PL for dots with $\text{x=0.13.}$ This polarization change has been attributed to the dot shape change using transmission electron microscopy images. These results suggest that the optical polarization anisotropy of the quantum dots can be controlled by manipulating the capping layer In composition.