We report high-power pedestal-free ultrashort pulses in a cascade compression system. In the self-compression stage, the 2 mu m ultrashort pulses with 123 fs duration and up to 21.7 W output power were obtained in a 0.3 m 50 mu m core diameter fiber. It is the highest self-compressing power ever obtained in a silica fiber with an all-fiber 2 mu m laser amplifier as the pump source. To obtain purer pedestal- eliminated pulses, we further increase the fiber length to 1 m to trigger the soliton self-frequency shifting (SSFS) effect. By employing an enhanced SSFS technique based on third- order dispersion (TOD) and filtering out the unshifted signal light, we finally achieved sub-150 fs, 10W-class, 1.2-MW peak-power, pedestal-free 2.07 mu m ultrashort pulses. This is also the highest, to the best of our knowledge, power and energy of Raman soliton obtained by SSFS in an ordinary silica fiber. (c) 2024 Optica Publishing Group
