High-power master-oscillator power amplifiers based on rare-earth-doped fibres

Abstract

In recent years there have been dramatic advances in fibre lasers. Currently, conventional single-strand cladding-pumped fibre lasers can generate output powers beyond 1 kW with high beam quality. Indeed, this fibre circuitry combined with pump-diode technology provides a unique high-gain environment for robust designs, which is also all-solid state, compact, stable, reliable, and reproducible. Here we review the recent progress in high-power MOPAs based on rare-earth-doped fibres and discuss fundamental aspects and prospects. We present our up-to-date experimental results with particular attention to a multitude of cladding-pumped, refined power amplifier regimes, including continuous-wave and pulsed fibre MOPA sources based on ytterbium-doped fibres operating at 1.1 µm and erbium:ytterbium co-doped fibres at 1.5 µm