All-fibered high-quality low duty-cycle picosecond high repetition rate pulse sources

In this work, we demonstrate all-fibered 20-GHz and 40-GHz picosecond pulse sources with duty cycles as low as 1/14. The pulse train is achieved viathe high-quality compression of an initial sinusoidal beating through four segments of optical fibers. We investigate the limits of the scalability to higher repetition rates.