Third-order nonlinear optical susceptibility and photoionization of an exciton in quantum dots

In this study, an investigation of an exciton in a disk-like quantum dot has been carried out by using the matrix diagonalization method and the compact density-matrix approach. The dependences of binding energies of excitons for the light and heavy hole masses on the size of the confining potential are analyzed explicitly. The third-order nonlinear optical susceptibility of third harmonic generation as well as the photoionization cross section has been calculated for the light-hole and heavy-hole excitons. The results are presented as a function of the incident photon energy. The results show that the third-order nonlinear optical susceptibility and the photoionization cross section of an exciton in a quantum dot are strongly affected by the dot size and the hole mass.

► The third-order susceptibility for light- and heavy-hole excitons in quantum dots is investigated. ► The binding energy is strongly affected by dot size and hole mass. ► It is possible to manage the resonance frequency and amplitude of third-order susceptibility by controlling dot size.