Femtosecond Mamyshev oscillator with 10-MW-level peak power

Ultrafast fiber lasers exhibit high broadband gain per pass, superior thermo-optical properties, and excellent beam quality, making them very suitable for practical use. For simplicity and efficiency, advanced mode-locked oscillator designs which can compete with the amplifier systems are always favorable. Here, we demonstrate a high-peak-power Mamyshev oscillator based on single-polarization, large-mode-area photonic crystal fibers. Using properly arranged filters, the fiber oscillator directly emits pulses with 9 W average power at 8 MHz repetition rate, corresponding to a single-pulse energy exceeding 1 μJ. The pulses are dechirped to 41 fs outside the cavity, leading to a record oscillator peak power as high as 13 MW. With such unprecedented performance, the proposed single-stage oscillator should be very attractive for various applications.