Specifications: Erbium Erbium is a chemical element with the symbol Er and atomic number 68. A rare, silvery, white metallic lanthanide; Erbium is a solid in its normal state. It is a rare earth element, erbium is associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden. A trivalent element, pure erbium metal is malleable (or easily shaped), soft yet stable in air, and does not oxidize as quickly as some other rare-earth metals. Its salts are rose-colored, and the element has characteristic sharp absorption spectra bands in visible light, ultraviolet, and near infrared. Otherwise it looks much like the other rare earths. Its sesquioxide is called erbia. Erbium's properties are to a degree dictated by the kind and amount of impurities present. Erbium does not play any known biological role, but is thought by some to be able to stimulate metabolism[citation needed]. Erbium-doped glasses or crystals can be used as optical amplification media, where erbium ions are optically pumped at around 980nm or 1480nm and then radiate light at 1550nm. This process can be used to create lasers and optical amplifiers. The 1550nm wavelength is especially important for optical communications because standard single mode optical fibers have minimal loss at this particular wavelength. A large variety of medical applications can be found (i.e. dermatology, dentistry) by utilizing the 2940nm emission (see Er:YAG_laser) which is highly absorped in water (about 12000 1/cm).
