Erbium's primary applications are acting as doping materials for glass coloring, fiber optics and laser technology.
Because of its very narrow absorption band, it makes its salts pink. This effect make it ideal for making glasses used for eyeware and decorative glassware. Erbium can neutralize discoloring impurities such as ferric ions producing a neutral gray shade. It is commonly used as a photographic filter.
Er:YAG based laser is ideal for use in surgical applications due to its ability to deliver energy without thermally damaging in tissue.
In metallurgy, Er lowers the hardness and improves the workability of metals, therefore, it is a popular additive.