Er:YSGG (Erbium doped Yttrium Scandium Gallium Garnet) is a crystal that is used as a lasing medium in solid-state lasers. It is doped with erbium ions, which provide laser transitions at 1.54 μm. This makes it useful for a variety of laser applications, including medical treatments such as dermal resurfacing, skin rejuvenation, and dental procedures. Er:YSGG is a high-performance laser crystal, known for its high efficiency, low thermal loading, and good stability, which makes it well suited for industrial laser applications as well.