Nonlinear optical properties in square tangent quantum wells

The nonlinear optical properties in square tangent quantum wells are studied theoretically. We obtain eigenfunctions and energy eigenvalues by means of solving Schrödinger equation within the framework of effective mass approximation. Using the compact-density-matrix approach and iterative method, the analytic expressions of the third-harmonic generation (THG) coefficients, the optical absorption (OA) coefficients and the refractive index changes (RIC) are obtained. The results show that the THG coefficients are affected by d and U0, while the OA coefficients and the RIC are strongly affected not only by d and U0 but also by the incident optical intensity.