We recently demonstrated a seed modulation format that is effective in suppressing SBS in kW-class fiber amplifiers. By applying synchronous amplitude and frequency modulation, a broad low power seed spectrum can be spectrally narrowed via self-phase modulation as it is amplified, thus reducing the SBS gain and enabling narrower linewidths. Since the approach leverages the fiber Kerr nonlinearity, SBS suppression becomes more effective as fiber powers and lengths increase. We will present updated results extending this approach toward higher modulation depths, higher powers, and narrower linewidths.
|