The effect of spatial symmetry on the nonlinear optical rectification of lens-shaped quantum dots

The one-band k·p model, the compact density matrix approach and the iterative method are used to calculate the nonlinear optical rectification coefficient (ORC) of an electron confined in an asymmetric lens-shaped quantum dot (ALQD). Numerical results are presented for the typical GaAs ALQD. The effects of the size of the ALQD, the incident photon energy and the symmetry of the QD on the ORC are investigated. It is found that there is a scaling rule that connects the ORC to the size of the ALQD. Using this scaling rule, it is shown that the ORC increases, and its peak shifts to lower energies, with increasing dot size. Also, the ORC decreases with increasing mirror symmetry of the QD.