Transparency power calculation in Yb3+-doped fiber due to temperature variations

The critical power level provides an objective tool for the determination of the maximum power available in a fiber laser based on physical parameters as: core diameter, temperature, and absorption and emission cross section for both the pump and laser wavelengths. This work presents a theoretical study of critical power levels when Ytterbium-doped fibers are exposed to changes of temperature. We found that critical power curves extend their wavelength dependence, ranging from 1 mu m to 1.2 mu m when fibers were heated up 300 degrees K. Also we found that critical power values are large than those obtained in conditions of room temperature. While low critical powers were obtained at lower temperatures (around 77 degrees K) with a reduced interval of wavelengths from 1 mu m to 1.1 mu m.