Power limitation induced by nonlinear effects in pulsed high-power fiber amplifiers

The combining of double-clad (DC) doped fibers and semiconductor pump laser diodes has allowed the development of high power optical sources in CW or pulsed regimes. Compared to bulk medium, the main limitations for achieving high peak powers inside optical fibers are due to small mode field size and large propagation length. Nonlinear effects such as the optical Kerr effect, Stimulated Raman Scattering (SRS) or Stimulated Brillouin Scattering (SBS) can be observed in high power amplifiers as short as a few meters of doped fiber length. A description of the different non-linear dynamics for optical pulse amplification in dependence with temporal pulse duration (ps, ns and μs regimes) will be presented. Theoretical modelling has also investigated to confirm the observed signal distortions in the case of a ∼6 μm core doped fiber amplifier. The power increase requires the design of new doped fibers with a large core to enhance simultaneously stored energy and nonlinear effects threshold. The peak power threshold in dependence with temporal pulse duration (ps, ns and μs regimes) will be given in relation with core diameters of double-clad fibers. To cite this article: Y. Jaouën et al., C. R. Physique 7 (2006).