The dynamic Stark effect under a not-too-strong femtosecond excitation regime in quantum well structures

Abstract

Using straightforward time-dependent perturbation treatment, transient coherent radiation-semiconductor interaction mechanisms are investigated analytically in a quantum well structure (QWS) duly irradiated by a moderate power femtosecond laser with photon energy slightly less than the crystal bandgap energy. The transition energy is calculated by recognizing the finite potential well depth of the QWS. The effects of higher excitonic states on the Stark shift and self-energy correction are examined in GaAs/AlGaAs QWS. The study shows a red shift with increasing excitation intensity and the shift is also found to be less when all the discrete excitonic states below the band edge are considered together. An increased self-energy correction accompanies this red shift.