Linear and nonlinear optical absorptions of an exciton in a quantum ring

Optical absorptions of excitons have been studied in a quantum ring with parabolic confinement potential. Binding energies of the ground (L=0) and the first excited (L=1) states has been investigated as a function of the ring radius. Based on the computed energies and wave functions, the oscillator strengths have been examined, as well as the linear, third-order nonlinear and total optical absorption coefficients. The results are presented as a function of the incident photon energy. It is found that the electron–hole interaction and the ring radius have a great effect on the optical properties of excitons in a quantum ring.