Editing Erbium (section)

{{infobox erbium}}
'''Erbium''' is a [[chemical element]]; it has [[Symbol (chemistry)|symbol]] '''Er''' and [[atomic number]] 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a [[lanthanide]], a [[rare-earth element]], originally found in the [[gadolinite]] mine in [[Ytterby]], [[Sweden]], which is the source of the element's name.

Erbium's principal uses involve its pink-colored Er<sup>3+</sup> ions, which have optical fluorescent properties particularly useful in certain laser applications. Erbium-doped glasses or crystals can be used as optical amplification media, where Er<sup>3+</sup> ions are optically pumped at around 980 or {{val|1480|u=nm}} and then radiate light at {{val|1530|u=nm}} in stimulated emission. This process results in an unusually mechanically simple [[laser]] [[optical amplifier]] for signals transmitted by fiber optics. The {{val|1550|u=nm}} wavelength is especially important for [[optical communications]] because standard single mode [[optical fibers]] have minimal loss at this particular wavelength.

In addition to optical fiber amplifier-lasers, a large variety of medical applications (e.g. dermatology, dentistry) rely on the erbium ion's {{val|2940|u=nm}} emission (see [[Er:YAG laser]]) when lit at another wavelength, which is highly absorbed in water in tissues, making its effect very superficial. Such shallow tissue deposition of laser energy is helpful in [[laser surgery]], and for the efficient production of steam which produces enamel ablation by common types of [[dental laser]].