One- and two-photon absorption spectra of the quantum-confined transitions of CdS quantum dots are reported. The results show significant deviations from calculations based on the parabolic-valence-band approximation. The near-degenerate one- and two-photon transitions observed experimentally, and confirmed theoretically using Luttinger theory and numerical matrix diagonalization, clearly demonstrate the effects of valence-band mixing and Coulomb interaction.
