Polarization-maintaining, narrow-linewidth, Yb-doped fiber amplifier through PRBS phase modulation

Abstract

We present polarization-maintaining (PM), narrow-linewidth, Yb-doped fiber amplifiers (YDFA) including the result of CW ~400W, >85% slope efficiency and single-mode output, which is based on 6.6GHz pseudo-random binary sequence (PRBS) phase modulation frequency. And the 3-staged master oscillator power amplifier (MOPA) configuration greatly simplifies the high power all-fiber laser setup. By mitigating stimulated Brillouin scattering (SBS) and mode instability (MI), the way to power scaling toward kW-level of PRBS-based, PM, narrow linewidth fiber amplifier is also discussed.