Thermal effects on tapered holmium-doped fiber amplifiers

The temperature response of a tapered holmium-doped fiber amplifier and its impact in the performance of fiber lasers and temperature fiber sensors has numerically been analyzed. Different pump schemes and different longitudinal shapes of the tapered-doped fiber were investigated, and it was found that a parabolic shape of the tapered fiber amplifier in a co-propagating pump scheme shows the highest sensitivity to temperature changes. In particular, the temperature sensitivity of the amplified signal was 2.5 x 10(-4)degrees C for 1 W of pump power and 1 m of doped fiber length. In addition, this sensitivity can be increased up to 10 times for fiber lengths shorter than 1 m and pump powers lower than 300 mW. Our results can be used to describe the temperature response of tapered fiber amplifiers in the mid-infrared spectral region and contribute with new information for the development of fiber lasers and fiber temperature sensors. (C) 2020 Society of Photo-Optical Instrumentation Engineers (SPIE)