Encyclopedia … combined with a great Buyer's Guide!

Sponsoring this encyclopedia:     and others

Stability Zones of Laser Resonators

Posted on 2006-10-01 as a part of the Photonics Spotlight (available as e-mail newsletter!)

Permanent link: https://www.rp-photonics.com/spotlight_2006_10_01.html

Author: , RP Photonics Consulting GmbH

Abstract: A detailed understanding of the stability zones of laser resonators turns out to be essential for laser design. In particular, the alignment sensitivity of a laser can be strongly reduced by moving to the optimum stability zone. The article discusses some issues and quotes a helpful reference.

Dr. Rüdiger Paschotta

Ref.: V. Magni, “Multielement stable resonators containing a variable lens”, J. Opt. Soc. Am. A 4 (10), 1962 (1987); encyclopedia articles on stability zones, resonator design, laser design, alignment sensitivity of optical resonators, and others

It is well known that laser resonators exhibit stability zones, i.e. well-defined regions for parameters like a cavity arm length or the focusing power of an intracavity element, in which stable cavity modes exist. A linear optical resonator normally exhibits two such stability zones, even though one may observe only a single one under certain circumstances. While both stability regions have the same width e.g. in terms of focusing power of the thermal lens in the gain medium, they otherwise have very different properties. In particular, they can be very different concerning the alignment sensitivity of a laser. I have myself encountered an extreme case where a laser was very hard to align due to strong thermal effects in the gain medium. When I completely redesigned the laser resonator to operate in the other stability zone, it generated more than twice the output power and was much less critical to align. Note that the mode size was nearly unchanged compared to the original design, so the mode size is clearly not all what matters.

The mentioned fundamental resonator properties have been analyzed in detail in the paper cited above. As many people are not familiar with these details, they get one of the stability zones of their resonators just at random, and may therefore easily end up with a non-ideal design. With refined software, it is possible to systematically design laser resonators operating at the stationary point of the wanted stability zone while simultaneously meeting several other requirements.

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.

Note that you can also receive the articles in the form of a newsletter or with an RSS feed.


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

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

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: