Chinese Journal of Quantum Electronics
Exciton effects on third-harmonic generation in quantum wells via fractional-dimensional space approach
YU Feng-mei
Abstract
Exciton effects on the third-harmonic generation in GaAs/AlGaAs infinite and finite square quantum wells are calculated within the framework of the fractional-dimensional space approach.The wave functions and bound energies are obtained as functions of spatial dimensionality and the dimension is a function of the well width.For an infinite confining potential the dimension(D) has a transition from the 3D limit to 2D limit when the well width decreases.However,in a finite well,when the well width decreases below a given value,the dimension increases.The analytical expression of the third-harmonic generation is described using the compact density method and the iterative procedure.The numerical results show that the third-harmonic generation coefficient with considering exciton effects is 40%greater than the one without considering exciton effects and it is very sensitively dependent on the exciton confinement.In addition,the smaller the relaxation constant is,the larger the third-harmonic generation will be.