A model for diffraction-limited high-power multimode fiberamplifiers using seeded stimulated Brillouin scattering phaseconjugation

摘要

Diffraction-limited polarized stimulated Brillouin scatteringn(SBS) Stokes output from a multimode fiber is possible when the Stokesnbeam is the phase conjugate of diffraction-limited polarized pump lightnfrom a narrow-band master oscillator. Net amplification can be obtainednby interposing a gain medium, such as a fiber amplifier between thenmaster oscillator and the region of SBS generation. This paper proposesnand studies numerically a model which describes the space-time dynamicsnof SBS generation, including phase conjugation, attenuation, phononndecay, thermal noise, inhomogeneous broadening, and amplifier gain.nNoise reduction and phase locking are obtained by seeding the low-powernend of the fiber at the Stokes frequency. Simulations are described fornthe case of 1.064 Μm light amplification in a dual-clad Yb-dopednmultimode fiber amplifier