YAG (Y₃Al₅O₁₂) is an optically transparent, chemically robust crystalline oxide that serves as a host matrix for numerous rare-earth dopants. In nanoparticle form, it can be more readily dispersed or sintered into transparent ceramics and can exhibit improved luminescent or laser performance due to size control. YAG nanoparticles are widely used in phosphors for high-brightness LEDs, optical coatings, and high-power solid-state laser systems.