A semiclassical model for noise propagation in depleted-pumpoptical amplifiers

摘要

Erbium-doped and parametric fiber-optic amplifiers can be modelednas a cascade of “amplifying” beamsplitters, eachnrepresenting a short fiber section in which the pump is approximatelynconstant. Each beamsplitter obeys simple noise combination relations andnits gain is calculated from the standard rate equations. The proposednmodel allows for the management of pump depletion in a very simple waynby numerical analysis, avoiding direct quantum mechanical calculations.nSample noise propagation diagrams are reported for technicallynsignificant values of the parameters. For the four-wave-mixingnamplifier, it has been found that the 3-dB noise limit can be reachedneven for a strong gain compression