Generation of 110-W sub-100-fs Pulses at 100 MHz by Nonlinear Amplification Based on Multicore Photonic Crystal Fiber

We report a multicore photonic crystal fiber (PCF) amplification system delivering about 110-W laser pulses with a duration of sub-100 fs. This amplifier is seeded by a large mode area (LMA) PCF mode-locked oscillator with a repetition rate of 100 MHz. By a one-stage nonlinear amplification, the pulse energy is scaled up to 1.1 $\mu\text{J}$ . In addition, the amplified pulses can be compressed to as short as 83 fs, corresponding to a peak power of 13 MW. For the multicore fiber used in this letter, the 110-W output average power has already made the mode distribution unstable. The results show that the potential output power of a multicore LMA fiber is mainly limited by the mode instability compared with the accumulated nonlinearity.