Lifting the Confusion Concerning Doping Concentrations
Posted on 2006-07-01 (revised on 2006-07-02) as a part of the Photonics Spotlight (available as e-mail newsletter!)
Permanent link: https://www.rp-photonics.com/spotlight_2006_07_01c.html
Abstract: Unclear specifications of doping concentrations in laser crystals and glass fibers cause a lot of confusion. RP Photonics clarifies some issues.
Ref.: encyclopedia article on doping concentration
There are quite a few different ways to specify doping concentrations in laser crystals and glass fibers. Unfortunately, it is very often not made clear which definition is actually used. As a consequence, doping concentrations are quite commonly seen as a kind of house numbers: the crystal with the higher percentage of doping is expected to absorb the pump radiation better (hoping that both specifications were based on the same definition).
Knowing what these numbers really mean allows one to do useful calculations. For example, one may predict the pump absorption efficiency before one builds up a laser. Quite obviously, this can be more efficient than a “trial and error” approach of ordering different crystals and taking those which work best.
To clarify the situation, RP Photonics has recently published a new encyclopedia article on the issue of doping concentrations.
This article is a posting of the Photonics Spotlight, authored by Dr. Rüdiger Paschotta. You may link to this page and cite it, because its location is permanent. See also the RP Photonics Encyclopedia.
Questions and Comments from Users
Here you can submit questions and comments. As far as they get accepted by the author, they will appear above this paragraph together with the author’s answer. The author will decide on acceptance based on certain criteria. Essentially, the issue must be of sufficiently broad interest.
Please do not enter personal data here; we would otherwise delete it soon. (See also our privacy declaration.) If you wish to receive personal feedback or consultancy from the author, please contact him e.g. via e-mail.
By submitting the information, you give your consent to the potential publication of your inputs on our website according to our rules. (If you later retract your consent, we will delete those inputs.) As your inputs are first reviewed by the author, they may be published with some delay.