RP Photonics

Encyclopedia … combined with a great Buyer's Guide!

VLib
Virtual
Library

Sisyphus Cooling

Definition: a mechanism for laser cooling of atoms or ions

German: Sisyphos-Kühlung

Categories: methods, quantum optics

How to cite the article; suggest additional literature

Sisyphus cooling (or Sisyphos cooling) is a mechanism for laser cooling of atoms or ions using light forces. It was understood in 1985, after the observation that laser cooling experiments with cesium atoms can lead to temperatures well below the Doppler limit, that the simple mechanism of Doppler cooling is not a sufficient explanation. The mechanism of Sisyphus cooling is somewhat sophisticated. It involves a polarization gradient, as generated e.g. by two counterpropagating linearly polarized laser beams with perpendicular polarization directions (lin ⊥ lin configuration), and is therefore sometimes called polarization gradient cooling. The full explanation is based on the picture of dressed states [1]. An essential ingredient is that when atoms in a certain dressed state “climb uphill”, i.e. reach a position where their potential energy is relatively large, it becomes likely that they are optically pumped into another state for which the potential energy at that position is close to a minimum. In such a way, the polarization gradient introduces non-conservative light forces, which can reduce the average kinetic energy of atoms.

Sisyphus cooling has become important for optical frequency standards, because it makes it possible to cool atoms to very low temperatures (“sub-Doppler temperatures”), so that the linewidth of certain forbidden transitions becomes very small.

Bibliography

[1]J. Dalibard and C. Cohen-Tannoudji, “Dressed-atom approach to atomic motion in laser light: the dipole force revisited”, J. Opt. Soc. Am. B 2 (11), 1707 (1985)

(Suggest additional literature!)

See also: laser cooling, Doppler cooling, Doppler limit, recoil limit, optical frequency standards, frequency metrology
and other articles in the categories methods, quantum optics

How do you rate this article?

Click here to send us your feedback!

Your general impression: don't know poor satisfactory good excellent
Technical quality: don't know poor satisfactory good excellent
Usefulness: don't know poor satisfactory good excellent
Readability: don't know poor satisfactory good excellent
Comments:

Found any errors? Suggestions for improvements? Do you know a better web page on this topic?

Spam protection: (enter the value of 5 + 8 in this field!)

If you want a response, you may leave your e-mail address in the comments field, or directly send an e-mail.

If you enter any personal data, this implies that you agree with storing it; we will use it only for the purpose of improving our website and possibly giving you a response; see also our declaration of data privacy.

If you like our website, you may also want to get our newsletters!

If you like this article, share it with your friends and colleagues, e.g. via social media:

arrow