Electromagnetic response of 3D arrays of quantum dots

A phenomenological theory of electromagnetic response properties of regular ensembles of quantum dots has been elaborated on the basis of the effective medium approach. We show that the QD composite comprising QDs with a given axis of symmetry is effectively a uniaxial dielectric continuum and the phenomenon of birefringence is inherent in it. It has been shown that arrays of resonantly amplifying QDs exhibit, threefold splitting of the gain band. This fine structure of the gain band originates from both the diffraction of the electromagnetic field by single anisotropically shaped QD and the electromagnetic interaction of QDs in array. The analytical results are compared with that obtained via direct numerical simulation by a minimal autonomic block (MAB) method for a tetragonal array of disk-like and pyramidal QDs. The numerics quantitatively confirm our prediction.