Picosecond pulse generation in a passively mode-locked Bi-doped fibre laser

CW passive mode locking is achieved in a bismuth-doped fibre laser using a semiconductor saturable absorber mirror optimised for operation in the range 1100 — 1200 nm. The pump source is a cw ytterbium fibre laser (1075 nm, maximum output power of 2.7 W), and the pulse parameters can be tuned by varying the intracavity group velocity dispersion using a diffraction grating pair. Stable laser pulses are obtained with a duration down to τ_p ≈ 1.1 ps.