Wavelength tunable actively mode-locked Tm3+ doped fiber laser with GHz repetition rate

Abstract

Using a phase modulator to synchronize the longitudinal modes in an all-fiber cavity, we demonstrate a wavelength tunable (1955–2045 nm) diode pumped actively mode-locked Thulium doped fiber laser with tunable repetition rate up to 10 GHz with the shortest measured pulse width of 42 ps and average output power of 5 mW. We have performed a detailed analysis of the stable mode-locking regimes, including the self mode-locking condition that challenges the harmonic mode-locked operation. We demonstrate a supermode suppression ratio of > 50 dB across the entire wavelength band of operation while maintaining a pulse width and timing jitter of < 50 ps and < 1 ps, respectively.