Power amplifier for 1083 nm using ytterbium doped fibre

We have demonstrated a power amplifier for a single-frequency signal at 1083 nm as required in spectroscopic applications. It is based on a ytterbium doped silica fibre which was pumped by a MOPA semiconductor laser at 978 nm. In a preliminary experiment we achieved 14 dB gain and 60 mW of amplified signal. We discuss the design considerations, the possibility of significant improvements of output power and gain, and the relevance of the amplifier for high resolution spectroscopy.