Used in the production of specialty optical fibers and laser materials due to its ability to enhance infrared transmission and improve thermal stability. Incorporated into solid-state lasers for medical and dental applications, particularly in procedures requiring precision cutting and ablation. Serves as a dopant in fluoride glass systems to modify refractive index and improve performance in fiber-optic communication systems. Applied in research settings for developing new luminescent materials and upconversion phosphors used in displays and bioimaging. Also utilized in nuclear reactors as a neutron absorber because of its high neutron capture cross-section.