3  kW power-level all-fiberized superfluorescent fiber source with linear polarization and near-diffraction-limited...

In this paper, we demonstrate a high-power linearly polarized all-fiberized superfluorescent fiber source (SFS) with near-diffraction-limited beam quality. The laser system is based on a master oscillator power amplifier configuration, which mainly consists of a polarization-maintained (PM) broadband SFS and multistage PM fiber amplifiers. A linearly polarized fiber laser over 3 kW is obtained at a pump power of about 4.3 kW with the corresponding slope efficiency of 71.9%. The polarization extinction ratio and the beam quality (M² factor) of the output laser are about 12.7 dB and 1.18, respectively, at the maximum output power. To the best of our knowledge, this is the highest output power of a linearly polarized broadband SFS with near-diffraction-limited beam quality.