Effect of temperature profiles on Yb3+-doped fiber amplifiers

We present a numerical analysis of the thermal effect of an Yb3+-doped fiber segment subjected to different temperature variation profiles, with the intention of determining the best energy conversion efficiency. The analysis is carried-out using different pump schemes and singular temperature profiles in Yb3+-doped fibers. The study indicates that a temperature distribution, with a concave parabolic profile along the fiber axis, shows higher stability in a fiber amplifier scheme, and it therefore becomes steadier at higher pump power level. Additionally, we find that for a constant temperature profile of 20 degrees C, the highest energy conversion efficiency occurs with a fiber segment of approximately 1.8 m, while for a constant temperature of 200 degrees C the maximum conversion occurs for a fiber span approximately 2.31 m. This makes it useful for using it as a sensor, at a temperature in a range of 20 degrees C to 200 degrees C. These results can be employed as a tool for optimization in the design of fiber lasers and amplifiers as sensors.