Abstract
Narrow-linewidth high-power fiber amplifiers are demanded in the spectral beam combining technique for power scaling. This article has experimentally studied the seed power spectral density (PSD) effect on the spectral broadening in all-fiber high-power narrow-linewidth fiber amplifier based on fiber Bragg grating (FBG) structure. It was found that the spectral bandwidth of the amplifier output reduces by increasing the PSD of the seed source. During the experiments, a ytterbium-doped fiber (YDF) amplifier was injected by three seed sources with the PSDs of 1.27 W/pm, 1.5 W/pm and 1.8 W/pm to scale up the seed power. After amplification, the resultant 3-dB spectral bandwidth of the amplifier was measured to be 88 pm, 61 pm, and 41 pm, respectively, at kW-level power. Meanwhile, we developed a 990 W fiber amplifier with a 3-dB spectral bandwidth of 41 pm; the narrowest spectrum achieved using a simple FBG-based master oscillator power amplifier configuration at this power level.
Reference32 articles.
1. 302 W triple-frequency, single-mode, linearly polarized Yb-doped all-fiber amplifier
2. High brightness, high SNR radio-frequency signal generated by an all-fibered linear-polarization single-mode dual-frequency fiber laser
3. High average power quasi-cw single-mode green and uv fiber lasers;Avdokhin,2015
4. Industrial grade 100 kw power cw fiber laser;Shcherbakov,2013
5. Sm green fiber laser operating in cw and qcw regimes and producing over 550w of average output power;Gapontsev,2014