<p>This study provides a comprehensive theoretical investigation of the nonlinear structural, electronic, and optical properties of oligomeric systems made of C₂₀ and C₆₀ fullerenes, which serve as model systems for fullerene-based carbon nanowires. DFT calculations were employed to perform full-scale geometric optimizations and evaluate key electronic properties. The computational results showed that dimers, trimers, and tetramers formed from C₂₀ and C₆₀ fullerenes are well stable. It was also shown that the extension of the fullerene-containing chains leads to a significant reduction in the HOMO-LUMO energy gap, which is accompanied by an increase in the density of electronic states near the Fermi level - indicating an increase in charge transport capabilities. Nonlinear optical analyses reveal significant improvements in first-order and superpolarizabilities for the extended and hybridized configurations, highlighting their potential application in future nano-optoelectronic and photonic applications. These results provide insights for the rational design of nanostructured materials with tailored physicochemical properties.</p>