Linearly-polarized narrow-linewidth random fiber laser seeded fiber MOPA

Abstract

We propose and experimentally investigate a linearly-polarized narrow linewidth random fiber laser (RFL) operating at 1080 nm and boost the output power to kilowatt-level with near-diffraction-limited beam quality by a master-oscillation-power-amplifier (MOPA) configuration. The RFL based on half-opened cavity generates 0.71 W seed laser with 88 pm full width at half-maximum (FWHM) linewidth and 22.5 dB polarization extinction ratio (PER) for power scaling. Two stage fiber amplifier enhances the seed laser to maximal 1.01 kW with a PER value of 17 dB and a beam quality of Mx ² =1.15 and My ² =1.13. The FWHM linewidth of amplified random laser broadens linearly as a function of output power with a coefficient of about 0.1237 pm/ W. To the best of our knowledge, this is the first demonstration of linearly-polarized narrow linewidth RFL with even kilowatt-level near-diffraction-limited output.