73 nJ 109 fs Yb doped fiber laser at 19 MHz repetition rate in amplifier similar

We report femtosecond pulse generation in an amplifier similariton oscillator and a prechirped fiber amplifier system. The final output power is 1.4 W, and the fundamental repetition rate is 19.1 MHz after a single state fiber amplifier. The pulsewidth is 109 fs.