Towards high-power MOPA architectures in single-mode fibers for mid-IR mode-locked operation

We report on a master oscillator power amplifier (MOPA) system at 2.8 µm to achieve an average power of 10.28 W with a pulse energy and peak power of 403 nJ and 5.76 kW, respectively. The seed, a semiconductor saturable mirror (SESAM) based mode-locked linear cavity source, delivers approximately 70 ps pulses at 28.16 MHz. Two amplifier stages are utilized in counter-pumping and dual-pumping configurations to enable high extraction efficiency and signal gain. To the best of our knowledge, this result is the highest average power and pulse energy obtained from a SESAM-based 2.8 µm mode-locked laser employing ZBLAN fiber MOPA architecture. It paves the way for achieving high average power in-fiber nonlinear amplification in single-mode fibers in the mid-infrared wavelength region.