Low-noise 2-GHz figure-9 fiber laser based on passive harmonic mode-locking.

We have proposed and demonstrated the generation of a high-repetition-rate ultrashort pulse with long-term stability and low noise based on a harmonic mode-locked (HML) figure-9 fiber laser. Different HML orders from the 2nd to the 13th are generated by adjusting the pump power, net dispersion, and wave plate angles. A 2-GHz HML pulse is obtained with a 155-MHz fundamental repetition rate in a Yb-doped fiber laser, and the corresponding supermode suppression level is as high as 50 dB.

Generation of sub-100 fs pulses from a SESAM-NPE hybrid mode-locked Yb-doped fiber laser at a fundamental repetition rate of 1.15 GHz.

Supercontinuum generation via direct pumping of unamplified high-repetition-rate, sub-100 fs pulses with a pulse energy lower than 50 pJ is superior in noise performance and features a high acquisition speed. We demonstrate a novel, to the best of our knowledge, gigahertz-repetition-rate, mode-locked Yb-doped fiber laser, where the hybrid mode-locking approach is employed. The laser has a low initiating threshold of 300 mW and a broad mode-locking range of 600 mW (300-900 mW) in terms of pump power.