Third-order nonlinear optical properties of excitonic state in a semiconductor quantum dot

摘要

By considering usual matrix procedures we examine how the exciton affects the nonlinear optical properties of 3-D semiconductor GaAs quantum dot. We calculate the third-order optical susceptibility of the GaAs (well) AlxGaAs1-x (barrier), and consequently the refractive index and the absorption coefficient. By increasing the Al content (x) in barrier material, carrier relaxation time is enhanced and the susceptibility peaks and their positions showed a blue shift, which agrees with the existing experimental work. For an anisotropic QD, the third-order nonlinear absorption coefficient depends strongly on the quantum dot width.