The Generation of 1.2 μJ Pulses From a Mamyshev Oscillator Based on a High Concentration, Large-Mode-Area Yb-Doped Fiber

We demonstrate a high-energy and high-average power Mamyshev oscillator based on a high performance large-mode-area step-index germanosilicate-cladding Yb-doped fiber. The oscillation of higher-order modes is effectively suppressed by employing appropriate intracavity spatial mode filtering, allowing significant scaling of single pulse energy. The laser directly generates a nearly diffraction-limited beam with an average power of 17 W operating at the fundamental repetition rate of 14.01 MHz, corresponding to a pulse energy of 1.2 mu J. The pulses could be externally dechirped to similar to 58 fs, leading to a peak power of similar to 13 MW. To the best of our knowledge, this is the highest pulse energy with sub-100 fs duration ever obtained directly from a mode-locked fiber oscillator.