Communications in Theoretical Physics
Mechanisms and modulation of third-order nonlinear optical responses in spherical quantum dots confined by a Mie-type potential
Yue Wu, Xuechao Li
Abstract
Abstract This paper systematically explores the third-order nonlinear optical properties and modulation mechanisms of a spherical quantum dot system confined by a Mie-type potential. We analytically solve the Schrödinger equation with Nikiforov–Uvarov method based on effective mass approximation to obtain the eigenenergies and wave function of the system. Subsequently, key third-order nonlinear optical parameters, including the third-harmonic generation (THG) coefficient, total optical absorption coefficients, and refractive index changes, are derived via the density matrix formalism. The results indicate that the nonlinear optical responses strongly depend on the geometric dimensions and the microscopic confinement parameters. By adjusting these parameters, effective control over the THG coefficient can be achieved. Furthermore, this study reveals the significant modulation effects of environmental factors. The synergistic influence of quantum dot size, confinement potential, and environmental interactions is systematically analyzed, providing a theoretical basis for designing high-performance nonlinear optical devices based on quantum dots.