10-W Level Picosecond Yb³⁺-Doped All-Fiber Laser Source at 976 nm

In this paper, we present the demonstration of a 10-W level picosecond Yb3+-doped master oscillator and power amplifier at 976 nm in all-fiber configuration. A linear-cavity Yb3+-doped fiber laser mode-locked by a semiconductor-saturable-absorber-mirror was developed as the seed laser with a pulse width of 10.9 ps operating at a repetition rate of 34.1 MHz. The average power of the picosecond mode-locked laser was amplified to 8.1 W by two core-pumped pre-amplifiers and two cladding-pumped power amplifiers. The pulse width of the output mode-locked laser was measured to be 15.6 ps and its pulse energy is 237.5 nJ, corresponding to a peak power of 15.2 kW. The polarization extinction ratio and beam quality (M2) of this 10-watt-level mode-locked laser were measured to be 13 dB and 1.2, respectively.