Nonlinear optical response of a strongly-driven quantum dot exciton-biexciton system

We examine the effective linear and the third-order nonlinear optical susceptibilities of an InAs/ GaAs semiconductor quantum dot with a cascade exciton-biexciton configuration that is strongly driven by a nearly resonant pump electromagnetic field, while, at the same time, it interacts with a weak electromagnetic field. We assume that the applied fields are linearly polarized, which permits us to simplify the relative energy level diagram by using a three-level ladder-type scheme. We derive the equations of motion, in the dipole approximation, in a rotating frame, and follow an expansion approach to calculate the components of the density matrix which are associated to the effective linear and the self-Kerr third-order nonlinear optical susceptibilities. We present the spectra of the first-order susceptibility and the self-Kerr susceptibility and investigate the dependence of their profiles on the Rabi frequency and the detuning of the pump field, in the one-photon and the two-photon resonance regimes. The role of the biexciton energy shift on the susceptibilities is also studied. In addition, we present a dressed state analysis which appears to be crucial for obtaining a better understanding of several spectral properties of the susceptibilities.

Automated summary

We investigate the optical susceptibilities of a semiconductor quantum dot with an exciton-biexciton configuration driven by a resonant pump field and interacting with a weak field. The linear polarized applied fields simplify the energy level diagram. By using a dipole approximation and a rotating frame, we derive the equations of motion and calculate the density matrix components related to the linear and nonlinear susceptibilities. We analyze the spectral properties of the first-order susceptibility and the self-Kerr susceptibility, considering the Rabi frequency and the detuning of the pump field, as well as the biexciton energy shift.