Emission spectra of Ho-doped fiber laser for two values of the output power Holmium fiber laser based on the heavily doped active fiber

Abstract: We have made and studied a set of the fiber lasers based on Ho-doped fiber with high concentration of the active ions. For the first time the spectral efficiency in a range of 2.02 -2.15 μm was determined. The highest output power of 4.2 W was detected at 2.1 μm with the efficiency slope of 34%. This value of the efficiency is highest for pure holmium-doped silica fibers