Experimental study of the SBS effect in multitone-driven narrow-linewidth high-power all-fiber amplifiers

Theoretical research on stimulated Brillouin scattering (SBS) suppression shows that the SBS threshold in multitone-driven narrow-linewidth high-power amplifiers can be enhanced. In this paper, a two-stage amplification all-fiber amplifier system is set up to investigate SBS effect in multitone-driven high-power amplifiers. In one case the system is seeded with a 1064 nm single frequency laser with output power of 43 mW. In another case the system is seeded with a narrow-linewidth laser with center walvelength around 1064 nm and output power of 45 mW. In the last case the system is seeded with both the aforementioned lasers. Experimental results are in excellent agreement with the theoretical predictions. The SBS threshold in the last case is highest in those three cases.