33.8 W Mid-infrared 2.8 μm Er-doped fiber laser with high optical efficiency
Junxiang Zhang, Shijie Fu, Quan Sheng, Lu Zhang, Wenxin Xia, Wei Shi, Jianquan Yao
Abstract
We demonstrate an efficient, high-power single-end-pumped Er-doped ZBLAN (Er:ZBLAN) fiber laser operating at 2.8 μm. A maximum laser power of 33.8 W at a wavelength of 2.87 μm was achieved with an optical efficiency of 26.4 %. A maximum slope efficiency of 32.8 % was obtained, which approaches the Stokes efficiency of the intrinsic Er3+ energy transfer up-conversion process. We examine both experimentally and theoretically, the change in optical efficiency in relation to output coupling ratios, laser wavelength, and pump power. Simulations demonstrate that the Er:ZBLAN fiber laser system exhibits high gain at 2.8 μm, and red-shifting of the laser wavelength results in reduced laser field reabsorption and increased laser efficiency. To the best of our knowledge, this work demonstrates the highest output power generated from a single-end-pumped Er-doped fluoride fiber laser.