In this study the third order nonlinear susceptibilities are theoretically
calculated for an electron confined in an isolated PbS/ CdSe/ CdS spherical core-shellshell
quantum dots. Our calculation is associated with intersubband transitions in the
conduction band. We used the effective mass approximation in this study which is a
simple and straightforward study of the third-order optical nonlinearity in nanometersized
parabolic quantum dots and solved a three-dimensional Schrӧdinger equation. The third
order nonlinear susceptibilities are analyzed as function of core, shell radii. Our study
show great dependence of third order nonlinear susceptibilities on size of core and shell.
Also In the case of Kerr-type nonlinearities, nonlinear refractive index n2 and the
nonlinear absorption coefficient β are investigated as function of the ratio k0/n0 (where n0
and k0 are the real and imaginary part of linear refractive index respectively) for different
value of imaginary and real parts of the third order susceptibility. Manuscript profile