<p>This study investigates the effects of rare earth ion doping (Eu³⁺-doping, Y³⁺-doping, and Eu³⁺–Y³⁺ codoping) on the structural and optical properties of Chalcogenides (Ge₂₂As₂₀Se₅₈) using the melt-quench approach. Structural and optical characterization studies, such as XRD and TEM study reveal that rare-earth doping enhances the amorphous character, with codoping leading to highest amorphosity. FTIR analysis suggests that codoping improves mid-infrared transmission transmission beyond 90%, attributed to reduced phonon energy and optimized local bonding. Further, Raman spectra investigation indicates dopant interaction with selenium atoms and modifications in vibrational modes in the glass samples. The UV–Vis DRS study confirms dual optical band gaps, with a transition from direct to indirect bandgap upon doping. While single doping reduces the bandgap due to increased disorder, codoping leads to a slight increase in bandgap compared to singly doped samples, suggesting reduced crystallinity and restricted resonant bonding. Moreover, these results provide information on tailoring the structural and optical characteristics of Eu³⁺–Y³⁺ codoped chalcogenide glasses, which can be explored further in photonic and optoelectronic applications.</p>