Characterization and modeling of amplified spontaneous emission in unsaturated erbium-doped fiber amplifiers

The generation of amplified spontaneous emission (ASE) in erbium-doped fiber amplifiers (EDFAs) is characterized. A theoretical model, leading to closed-form analytical expressions for the backward and forward ASE power spectra, is developed for the unsaturated gain regime. This study shows that for the unsaturated gain regime, both power and spectral distributions of the ASE can be well described through the closed-form expressions, which require only measurable experimental parameters.<>