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Definition: a measure of the strength of optical amplification

German: Verstärkung, Verstärkungsfaktor

Categories: lasers, optical amplifiers

Formula symbol: g, G

Units: %, dB or dimensionless number

How to cite the article; suggest additional literature


In photonics, the term gain is usually used to quantify the amplification of optical amplifiers. Different meanings occur in the literature:

Apart from its magnitude, important properties of gain are its spectral bandwidth and its saturation characteristics.

The gain achieved e.g. in a fiber amplifier or the gain medium of a laser depends on the population densities in different electronic levels, which themselves depend on the optical intensities. Rate equation modeling may be used for calculating the gain and investigating its dependence on various influences.


[1]R. Paschotta, tutorial on "Fiber Amplifiers", part 2 on gain and pump absorption

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See also: gain media, gain bandwidth, gain clamping, optical amplifiers, fiber amplifiers, gain saturation, gain narrowing, gain switching, gain efficiency, homogeneous saturation, inhomogeneous saturation
and other articles in the categories lasers, optical amplifiers


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