Low repetition rate Yb-doped all-fiber Mamyshev oscillator

We have developed a fiber Mamyshev oscillator with a sub-MHz fundamental repetition rate that generates 20 nJ femtosecond pulses at 1030 nm. To achieve such a low repetition rate, a 100-m linear cavity in combination with two chirped fiber Bragg gratings for dispersion compensation were required. Lower repetition rates should be achievable by adjusting the parameters of the laser cavity. Such a laser used as a seed could replace pre-amplification and pulse-picking stages in chirped-pulse amplification systems.