The effect of temperature on the population distribution within the manifold of an Er<sup>3+</sup>-ion pumped at 1480 nm pump wavelength is theoretically investigated. A modified rate equation model for determining the signal gain performance of EDFAs is established by including the temperature effect and the gain values versus launched pump powers at the temperature range of -20 to 60 °C are obtained under the signal power regime.
We present the schematic representations for teaching the procedure of optical amplification in erbium and praseodymium doped fiber amplifiers by using rate equations models. The behaviour of these types of amplifiers is the same as three (for erbium ion) and four (for praseodymium ion) levels atomic systems, respectively. Most of the important characteristics of these amplifiers can be obtained from these simple models and their underlying assumptions. Hence, we can make use of these approaches for teaching the purposes of procedures in fiber amplifiers. For this aim, the gain performances of Er<sup>3+</sup> and Pr<sup>3+</sup>-doped fiber amplifiers are investigated at the educational level, using the temperature-dependent rate equation model.