3.53 kW average power all-fiber amplifier with 0.16nm narrow-linewidth single-mode beam quality

In this manuscript, a 3.53kW average output power all-fiber laser system at 1064nm with 3dB linewidth as narrow as 0.16nm and near single-mode beam quality (M 2 ≈1.7) is demonstrated. There is no obvious stimulated Brillouin scattering, stimulated Raman scattering or amplified spontaneous emission observed. To the best of our knowledge, this is the highest output power of all-fiber laser system with narrow-linewidth and near single-mode beam quality ever reported.