A 2 kW, 8 GHz-Linewidth Yb-Doped Polarization-Maintained Fiber Laser with Quasi-Flat-Top Pseudo Random Binary Sequence Phase Modulation for SBS Suppression

• Published in: Nanomaterials (Basel, Switzerland) Vol. 13; no. 8; p. 1329
• Main Authors: Kim, Dong Joon, Koo, Joonhoi, Jun, Seung Won, Jeong, Hwanseong, Lee, Hwihyeong, Lee, Jung Hwan, Jo, Minsik
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.04.2023; MDPI
• Subjects: Amplifiers; Equipment and supplies; fiber laser; Fiber lasers; Fiber optics; Field programmable gate arrays; Gravitational waves; Lasers; Master oscillator/power amplifier; narrow linewidth; Phase modulation; Polarization; polarization-maintaining fiber; Power amplifiers; pseudo random binary sequence; Japan; polarization-maintaining fiber; pseudo random binary sequence; narrow linewidth; fiber laser
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano13081329

We demonstrated a narrow-linewidth high-power Yb-doped polarization-maintaining (PM) fiber laser with near-diffraction-limited beam. The laser system consisted of a phase-modulated single-frequency seed source and four-stage amplifiers in the master oscillator power amplifier configuration. A quasi-flat-top pseudo random binary sequence (PRBS) phase-modulated single-frequency laser with a linewidth of 8 GHz was injected into the amplifiers for suppressing stimulated Brillouin scattering. The quasi-flat-top PRBS signal was readily generated from the conventional PRBS signal. The maximum output power was 2.01 kW with polarization extinction ratio (PER) of ~15 dB. The beam quality (M2) was less than 1.3 over the power scaling range.