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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 waveguidesfiber optics and waveguides, nonlinear opticsnonlinear optics


Cite the article using its DOI: https://doi.org/10.61835/08e

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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 <$\chi^{(3)}$> 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 <$\chi^{(2)}$> 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.


tutorial passive fiber optics

Passive Fiber Optics
Part 11: Nonlinearities

We discuss origins and effects of nonlinearities in passive optical fibers.

case study Raman scattering in fiber amplifier

Case Studies

Case Study: Raman Scattering in a Fiber Amplifier

We investigate the effects of stimulated Raman scattering in an ytterbium-doped fiber amplifier for ultrashort pulses, considering three very different input pulse duration regimes. Surprisingly, the effect of Raman scattering always gets substantial only on the last meter, although the input peak powers vary by two orders of magnitude.

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Case studies:

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[1]D. Castelló-Lurbe et al., “Nonlinearity measurement undergoing dispersion and loss”, Opt. Lett. 48 (2), 493 (2023); https://doi.org/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!)

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