Polarization Independent Ground State Optical Transitions in Closely Stacked InAs/GaAs Columnar Quantum Dots

This work presents an analysis of the electronic and optical properties of InAs/GaAs columnar quantum dots (QDs) by performing multi-million-atom tight-binding simulations. The plots of the polarisation-dependent ground state optical transition strengths predict that a nearly zero degree of polarisation can be achieved at 1550 nm emission/absorption wavelength by engineering the number of QD layers in a columnar QD. These results are promising for the design of optical devices requiring polarisation insensitive optical response such as semiconductor optical amplifiers.