frequency all - fiber laser in master oscillator power amplification configuration

We present a high power, single-frequency fiber amplifier based on master oscillator power amplification (MOPA) chains in all-fiber configuration. A 1.5 meter long highly doped Yb fiber with absorption coefficient as high as 16 dB/m at the 975 nm wavelength is used for the main power amplifier, no special assistant stimulated Brillouin scattering (SBS) suppression approach is employed. The maximal output power of the single-frequency fiber amplifier is 310 watt and of good beam quality with a measured M factor about 1.3. The amplifier is tested more than 10 hours, no obvious power decrease is observed. To the best of our knowledge, this is the highest power of single-frequency fiber amplifier in all-fiber format. 10.00