SBS suppressed 2.82 kW, 10.34 GHz fiber amplifier using real-time p-tunable phase modulation via parallel LFSR structures

Power scaling of high-power narrow-linewidth continuous-wave fiber lasers is limited by stimulated Brillouin scattering (SBS). While inversion probability-tunable (p-tunable) sequence modulation offers dynamic spectral control for enhanced SBS suppression, its practical implementation has been hindered by reliance on complex, expensive arbitrary waveform generators (AWG) or significant hardware complexity (particularly demanding logic resource requirements) of conventional field-programmable gate array (FPGA)-based implementations. This work introduces what we believe to be a novel, hardware-efficient approach to overcome these limitations. We present a hardware-efficient parallel linear feedback shift register (LFSR) architecture with comparator probability adjustment, enabling real-time, precise p-value control at 10 GHz clock rates, significantly reducing cost and complexity. Concurrently, we establish a quantitative acoustic-photonic dynamics model based on a time-dependent three-wave coupled equation, solving the nonlinear interactions among signal laser photons, phonons, and Stokes waves under p-tunable modulation. This model enables systematic optimization, theoretically predicting and experimentally confirming maximal SBS threshold enhancement at p = 0.58. Leveraging this optimized parameter, our system achieves 2.82 kW output power with a 10.34 GHz FWHM linewidth. Compared to systems using pseudo-random binary sequence (PRBS) modulation (achieving 2.46 kW at ∼10 GHz FWHM linewidth), this represents a 13% increase in output power. This integrated hardware-theory solution provides a practical and effective approach for SBS suppression in high-power narrow-linewidth fiber lasers, enabling higher power scaling and stable operation.