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

More specific term: parametric nonlinearities

German: Nichtlinearitäten

Categories: fiber optics and waveguides, nonlinear optics

How to cite the article; suggest additional literature


URL: https://www.rp-photonics.com/nonlinearities.html

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 the following:

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

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.

Nonlinear Effects in Fiber Optics

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.

Fibers usually not do not exhibit a χ(2) nonlinearity due to the symmetry properties of the used glass. Under certain circumstances, this can be changed, e.g. by poling the glass with a strong electric field.

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[1]D. Castelló-Lurbe et al., “Nonlinearity measurement undergoing dispersion and loss”, Opt. Lett. 48 (2), 493 (2023), doi:10.1364/OL.481445
[2]G. P. Agrawal, Nonlinear Fiber Optics, 4th edn., Academic Press, New York (2007)
[3]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, highly nonlinear fibers, The Photonics Spotlight 2007-09-01
and other articles in the categories fiber optics and waveguides, nonlinear optics


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