Fourier-limited 19 ps Yb-fiber seeder stabilized by spectral filtering and tunable between 1015 and 1085 nm

We report a passively mode-locked picosecond
ytterbium-doped fiber laser operating in the normal dispersion
regime, tunable over 70 nm around 1.05 μm. Mode-locking
operation is achieved through a free-space coupled semiconductor
saturable absorber. An external grating in Littrow configuration
is used for both tuning and mode-locked stabilization through
spectral filtering. Pulse duration of 19 ps with pulse repetition
rates below 20 MHz is obtained with a maximum average
output power of 1.5 mW.