Encyclopedia … combined with a great Buyer's Guide!

Sponsors:     and others

Doppler Broadening

Definition: broadening of the linewidth of atomic transitions, caused by random motion of the emitting atoms

German: Doppler-Verbreiterung

Category: physical foundations

How to cite the article; suggest additional literature


Doppler broadening is the inhomogeneous broadening of the linewidth of atomic transitions caused by the random movements of atoms. For example, if the atoms have a thermal velocity distribution with temperature T, the linewidth resulting from the Doppler effect is

Doppler broadening

where ν0 is the mean optical frequency and m is the mass of the atoms. The Doppler broadening, e.g. for atoms in a gas cell, is typically much larger than the natural linewidth.

Doppler broadening can place severe constraints on precise spectroscopic measurements. However, it can be eliminated in various ways, e.g. by reducing the temperature (e.g. with laser cooling) or by employing a measurement scheme which is intrinsically insensitive to Doppler broadening, such as Doppler-free saturation spectroscopy or the use of two-photon absorption with counterpropagating beams.

Doppler broadening is the dominant line broadening mechanism in gas lasers.

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.

Your question or comment:

Spam check:

  (Please enter the sum of thirteen and three in the form of digits!)

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.

See also: linewidth, inhomogeneous broadening, Doppler cooling, laser spectroscopy
and other articles in the category physical foundations


If you like this page, please share the link with your friends and colleagues, e.g. via social media:

These sharing buttons are implemented in a privacy-friendly way!