3C fiber technology advances the performance frontier of practical, high-pulse-energy fiber lasers by providing very large core fibers with the handling and packaging benefits associated with single mode fibers. First-generation fibers demonstrate scaling to > 240 W average power coincident with 100-kW peak power in 1-mJ, 10-ns pulses while maintaining single-mode beam quality, polarized output, and efficiencies > 70%. Peak powers over 0.5 MW with negligible spectral distortion can be achieved with sub ns, near-transform-limited pulses. In-development second-generation 3C Yb-fiber based on core sizes around 55 μm1 have produced >8 mJ, 13 ns pulses with peak powers exceeding 600 kW.
3C (Chirally-Coupled Core) optical fiber establishes a technological platform for high brightness, power scalable lasers
with an engineerable fiber geometry that enables robustly single-mode performance of large core diameter fibers. Here
we report the demonstration of robust polarization preserving performance of 35 μm core 3C fiber for short pulse
systems. A polarization extinction ratio (PER) of ~ 20 dB is stably maintained with ambient temperatures varying over a
50°C range from a Yb-doped double clad 3C fiber amplifier. We also demonstrate that this high-PER polarization
output is insensitive to temperature gradients and mechanical perturbations in the 3C fiber amplifier. The ability to
deliver high peak power pulses at high average powers while maintaining exceptional beam quality and a stable
polarization state in an easily integrated format makes 3C fiber laser systems extremely attractive for harmonic
generation to visible and UV wavelengths.