MW-level 7ps high-power MOPA system with ytterbium-doped spun tapered double-clad fiber

This paper presents the development and experimental demonstration of all-fiber Master Oscillator Power Amplifier (MOPA) systems capable of delivering high-average-power and high-peak-power picosecond pulses. The systems incorporate two distinct all-glass gain modules utilizing active ytterbium-doped spun tapered double-clad fibers (sT-DCFs) with core diameters of 60μm and 92μm. Utilizing the 60μm core diameter sT-DCF amplifier, 7.3ps pulses at 26MHz repetition rate were amplified to achieve 200W average power and a peak power of 1MW. The 92μm core diameter sT-DCF amplifier demonstrated 7 ps pulses with 600 W average power at a high repetition rate of 182 MHz. Both systems delivered near-diffraction-limited beam quality (M2<1.4), indicating excellent spatial coherence and the capability to mitigate transverse mode instability (TMI) at high power levels. The alignment-free, all-glass design incorporates Ampliconyx APMX-TGM-xx/1040 1 kW gain modules highlight the potential of these MOPA systems for compact, efficient, and robust ultrafast fiber laser solutions. This design is particularly suited for a wide range of industrial applications requiring high average/peak power, superior beam quality, and reliable operation.