Single-frequency master-oscillator fiber power amplifier system emitting 20 W of power

Abstract

We report a master-oscillator fiber power-amplifier system consisting of a diode-pumped monolithic nonplanar ring laser as the master oscillator and a Yb-doped large-mode-area double-clad fiber as the power amplifier. The system emits up to 20.1 W of single-frequency radiation at a wavelength of 1064 nm with diffraction-limited beam quality (M(2)</=1.3) . The optical emission spectrum and amplitude-noise behavior are investigated. Furthermore, the power-scaling possibilities are discussed.