Theoretical study on third nonlinear optical susceptibility in In_xGa_1−xN/GaN cylindrical quantum dots

In this paper, the third-order nonlinear optical susceptibilities were carried out in In_xGa_1−xN/GaN cylindrical core–shell quantum dots by solving the three-dimensional Schrödinger equation in cylindrical coordinates. Using the effective mass envelope-function approximation, the electronic wave functions were evaluated. We have investigated the effect of the core and shell radii thicknesses on the energies as well as on the third-order nonlinear susceptibilities. Our results reveal that the susceptibility peak is redshifted for increasing the core or the shell radii. In addition, an enhancement of the optical nonlinearity is exhibited for increasing Ga concentration x. Our numerical results can be useful for electro-optical modulators, laser diodes and photodetectors by giving a new degree of freedom in optoelectronic device applications. (paper)