5-GHz pulsed fiber Fabry-Perot laser mode-locked using carbon nanotubes

We demonstrate passive mode-locking of a short-cavity (similar to 2 cm) fiber Fabry-Wrot laser by incorporating a carbon-nanotube-based saturable absorber. Stable pulses are generated with a pulsewidth as short as 0.68 ps at a repetition rate as high as 5.18 GHz. This is the smallest femtosecond fiber pulsed laser ever demonstrated to date.