Third-harmonic generation in asymmetric coupled quantum wells

The third-harmonic generation (THG) in asymmetric coupled quantum wells (ACQWs) for different values of the well parameter ΔΔ and width of barrier (WB)(WB) are theoretically studied. The analytical expression of the third-harmonic generation is derived by using the compact density-matrix approach and the iterative method. Finally, the numerical calculations are presented for typical GaAs/AlxGa1−xAs asymmetric coupled quantum wells. Results obtained show that the third-harmonic generation in the asymmetric coupled quantum wells can be importantly modified by the parameter ΔΔ and WBWB. Moreover, third-harmonic generation also depends on the relaxation rate of the asymmetric coupled quantum wells.