A delay-time tunable mode-locked erbium-doped fiber ring laser system

Summary form only given. Active harmonically mode-locking has been considered as one of the promising techniques to construct the ultrafast lasers with high-repetitive optical pulse-train and ultrashort pulsewidth. Based on this technique, the mode-locked erbium-doped fiber (EDF) ring laser which provides stable, nearly transform-limited, picosecond optical pulses with low timing jitter has been developed. In this work, we propose a phase (as well as delay-time) tunable picosecond laser source by integrating the EDF ring laser with a voltage-controlled phase shifter modified from a frequency-translated digital phase-locked loop (referred as PLL-PS). The performances of the novel delay-time tunable, mode-locked EDF laser such as tuning range, responsivity, and linearity are discussed.