In this paper the electronic spectra and optical properties of one-electron spherical quantum dot (QD) are presented. QD is composed of CdSe core surrounded by ZnS shell (barrier) CdSe shell and finally by medium of very high potential barrier (SiO2) compared to CdSe. The energy eigenvalues of s, p and d states and corresponding wave functions were calculated using effective mass approximation. We have calculated oscillator strengths and the linear and third-order nonlinear intersubband optical absorption coefficients as function of the QD dimension, incident photon energy and incident optical intensity for the 1s-1p, 1p-1d and 1p-2s transitions.
