Material and light-pulse parameter dependence of the nonlinear optical susceptibilities in the coherent χ⁽³⁾ regime in semiconductor quantum wells

A detailed numerical study of the third-order nonlinear optical susceptibilities (χ⁽³⁾) of semiconductor quantum wells is presented. The dependence of χ⁽³⁾ on material parameters (electron-hole mass ratio and exciton linewidths), on the light polarization configuration (co- and countercircularly polarized) and on the spectral configuration is discussed. The goal of this study is to map out the nonlinear phase shift per quantum well and a related figure of merit caused by quasi-resonant excitonic and biexcitonic nonlinearities induced by picosecond light pulses. The study is based on the dynamics-controlled truncation formalism and evaluated under the assumption that only 1s-heavy-hole excitons contribute to the nonlinearities. It includes all correlation effects (exciton-exciton scattering in the singlet and triplet channels and coherent biexciton formation in the singlet channel) that contribute within the coherent excitonic χ⁽³⁾ regime.