Nonlinear optical rectification in cubical quantum dots

The optical rectification (OR) coefficient for cubical quantum dots (CQDs), with an applied electric field is theoretically investigated in the framework of the compact-density-matrix approach and an iterative method. The confined wave functions and energies of electrons in the CQDs are calculated in the effective-mass approximation. Numerical calculations are presented for typical GaAs/AlAs CQDs. The results show that the calculation for OR coefficient in the CQDs system can reach a magnitude of 10-4m/V, two orders higher than that in the spherical quantum dots system. The OR coefficient strongly depends on the length of CQDs and the magnitude of electric field. And the peak shifts to the aspect of high energy when considering the electric field.