Used in specialized optical materials and laser technologies due to its luminescent properties in the near-infrared range. Employed in doping of solid-state lasers and amplifiers, particularly in fiber optics for telecommunications. Also investigated for use in upconversion processes where low-energy photons are converted to higher-energy emissions, useful in bioimaging and display technologies. Serves as a precursor in the synthesis of other erbium-containing compounds and thin films for advanced electronic and photonic applications.