Nonlinear optical absorption coefficients and refractive index changes in a two-dimensional system

The nonlinear optical absorption coefficients and refractive index changes in a two-dimensional system are theoretically investigated. It is shown that the factors of the incident optical intensity, the relaxation time and the carrier density of the system have important influences on the optical absorption coefficients and refractive index changes. Moreover, the optical absorption coefficients are strongly bleached with the incident optical intensity and the relaxation time increasing.