Suppression of self-pulsing in Yb fibre lasers coupled with external Fabry-Perot cavity

A simple technique to suppress self-pulsing behaviour in a fibre laser employing a two-mirror Fabry-Pérot external feedback cavity is reported. Feedback provided by the external Fabry-Pérot cavity enforces the fibre laser to oscillate in the selected longitudinal modes, resulting in robust laser operation without self-pulsing. This technique has been successfully applied to a double-clad Yb fibre laser, yielding a stable continuous-wave output of up to 9.8 W at 1050 nm. The advantages of this technique and the prospects of further improvement are discussed.