Optical Properties of Excitons in Low Dimensional Systems

Abstract

We show how to compute the linear and nonlinear optical spectra of Low Dimensional Systems (LDS) in the excitonic energy region using the dynamical density matrix approach. The advantage with respect to the usual quantum mechanical calculation, which makes use of the transition probability, is that we can obtain directly the optical functions and all coherence effects are automatically included. The method is applied to GaAs/Ga1—xAlxAs superlattices (SL), Quantum Wires (QWW) and Quantum Dots (QD), and the optical functions are computed, with inclusion of nonlinear effects in the case of the superlattice. In the case of QDs we present new results which give the properties of scattered optical waves.