Extreme energy pulsed fiber lasers

In this paper, we experimentally explored high energy and high peak power pulse generation in very large core multimode fiber amplifiers, achieving the highest ever reported energies of up to 82-mJ for 500-ns pulses, of up to 27-mJ for 50-ns pulses, and of up to 2.4-MW peak power for 4-ns long pulses at 1064 nm⁵. Fiber core sizes used in these studies ranged from 50-mum up to 200-mum, just above the single-transverse mode operation achievable with low-NA fibers with core diameters of up to ~50mum. Highly multimode nature of these very large core fibers was mitigated by using coiling-induced mode-filtering effect