Stimulated Brillouin scattering mitigation using optimized phase modulation waveforms in high power narrow linewidth...

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Stimulated Brillouin scattering (SBS) is a major limitation in high-power narrow linewidth fiber amplifiers.
• Mitigating SBS is crucial for advancing laser technology and applications.

Purpose of the Study:

• To demonstrate SBS mitigation in Yb-doped double-clad fiber amplifiers.
• To investigate the use of optimized external phase modulation for SBS suppression.

Main Methods:

• Utilizing optimized periodic waveforms generated by an arbitrary waveform generator.
• Employing multi-objective Pareto optimization based on a comprehensive SBS model.
• Experimentally testing the approach as a function of optical linewidth.

Main Results:

• Achieved significant SBS mitigation through optimized phase modulation.
• Measured an enhancement in the SBS threshold of approximately 10 GHz^-1 with respect to optical linewidth.
• Demonstrated that long-period waveforms are effective for both long and short fibers.

Conclusions:

• External phase modulation with optimized waveforms is a viable method for SBS suppression in fiber amplifiers.
• The developed optimization strategy effectively enhances the SBS threshold.
• Further investigation into modulation waveform parameters shows potential for broader applicability.