RP Photonics logo
RP Photonics
Technical consulting services on lasers, nonlinear optics, fiber optics etc.
Profit from the knowledge and experience of a top expert!
Powerful simulation and design software.
Make computer models in order to get a comprehensive understanding of your devices!
Success comes from understanding – be it in science or in industrial development.
The famous Encyclopedia of Laser Physics and Technology – available online for free!
The ideal place for finding suppliers for many photonics products.
Advertisers: Make sure to have your products displayed here!
… combined with a great Buyer's Guide!
VLib part of the


<<<  |  >>>

Definition: optical phenomena involving a nonlinear response to a driving light field

German: Nichtlinearitäten

Categories: fiber optics and waveguides, nonlinear optics

How to cite the article; suggest additional literature

Lasers can be used for the generation of light with very high optical intensities. These can give rise to a number of nonlinear optical effects (→ nonlinear optics), the most important of which are:

There are also various other effects which are not directly based on optical nonlinearities, but are nevertheless affecting optical phenomena:

In optical fiber technology, optical nonlinearities are of high interest. In fibers there is a particularly long interaction length combined with the high intensity resulting from a small mode area. Therefore, nonlinearities can have strong effects in fibers. Particularly the effects related to the χ(3) nonlinearity – Kerr effect, Raman scattering, Brillouin scattering – are often important, despite the relatively weak intrinsic nonlinear coefficient of silica: either they act as essential nonlinearities for achieving certain functions (e.g. pulse compression), or they constitute limiting effects in high-power fiber lasers and amplifiers.

Usually, the strength of nonlinear effects is determined by the peak power. However, there are cases where stronger effects occur for lower peak powers, as explained in a Spotlight article.

Strong nonlinearities also occur at intensities which are high enough to cause ionization in the medium. This can lead to optical breakdown, possibly even associated with laser-induced damage of the material. In gases, extremely high optical intensities can be applied, which can lead e.g. to high harmonic generation.


[1]G. P. Agrawal, Nonlinear Fiber Optics, 4th edn., Academic Press, New York (2007)
[2]R. Paschotta, tutorial on "Passive Fiber Optics", Part 11: Nonlinearities of Fibers

(Suggest additional literature!)

See also: nonlinear optics, effective nonlinear coefficient, laser-induced breakdown, nonlinear crystal materials, nonlinear frequency conversion, nonlinear polarization, nonlinear index, saturable absorbers, fibers, Spotlight article 2007-09-01
and other articles in the categories fiber optics and waveguides, nonlinear optics

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