This article presents the development and validation of a numerical simulator for optical communication systems that enables comprehensive modeling of signal transmission, propagation, and reception in fiber-optic channels. The proposed approach combines physical accuracy with computational efficiency, allowing for both scientific analysis and practical system design. The simulator implements the nonlinear Schrödinger equation using the split-step Fourier method to account for chromatic dispersion, nonlinearity, attenuation, and amplifier noise. Simulation results demonstrate a strong correlation with experimental data, showing a deviation within 5–7%, thus confirming the reliability of the model.