All-fiber fundamentally mode-locked 12 GHz laser oscillator based on an Er/Yb-doped phosphate glass fiber.

We have developed a compact and stable all-fiber fundamentally mode-locked 12 GHz laser system. The passively mode-locked laser centered at 1535 nm has temporal pulse width of ∼2  ps and average power of 5 mW. The timing jitter, which is cumulative from pulse-to-pulse, has been measured using an optical cross-correlation method and found to be 44  fs/pulse. The self-starting, mode-locked laser consists of a semiconductor-based saturable absorber with high modulation depth and a high gain per unit length, polarization-maintaining 0.8 cm long Er/Yb phosphate fiber as a gain medium.