In this study, we investigate the linear, third-order nonlinear, and total optical absorption coefficients (ACs) in GaAs/GaAlAs multilayer spherical quantum dots (MSQDs) within the effective mass approximation framework. Solving the Schrödinger equation via the finite element method, we analyze the effects of electric field (EF) strength and impurity position on optical absorption and oscillator strength (OS). Our results reveal that the presence and location of a donor impurity significantly influence the resonance peak positions and intensities of ACs, inducing shifts between blue and red wavelengths depending on the impurity’s position and barrier widths. Additionally, the EF modifies the ACs and OS nonlinearly, with effects contingent on system parameters such as barrier width. These findings provide valuable theoretical insights that could guide future experimental research and the design of optoelectronic devices based on multilayer quantum dots.