Linear and nonlinear optical absorptions of a two-electron quantum dot

The linear and nonlinear optical absorptions of a two-electron quantum dot are studied by using the matrix diagonalization method. The oscillator strength of the transition is calculated within the effective-mass approximation, along with the linear and the third-order nonlinear and the total optical absorption coefficients. The interaction and transition matrix elements of our methodology can be analytically obtained. It has been found that the linear and nonlinear optical absorptions strongly depend on the confinement strength, electron–electron interaction, the incident optical intensity, and the total spin of the system. It is shown that the influence of the confinement strength on the intersubband optical absorptions of the spin-singlet states is stronger than those of the spin-triplet states.