Used as a dopant in stainless steel to improve grain refinement and strength, enhancing mechanical properties and corrosion resistance. Employed in the production of special optical glasses and ceramics due to its stability and refractive properties. Serves as an active medium in solid-state lasers, particularly in high-power and ultrafast laser systems. Utilized in radiation-detecting devices because of its sensitivity to ionizing radiation. Also applied in research for quantum memory and photonic technologies owing to its favorable electron energy levels.