High-Power Femtosecond Pulse Generation From an All-Fiber Er-Doped Chirped Pulse Amplification System

We demonstrate a compact all-fiber Er-doped chirped pulse amplification (CPA) system that can produce ~344 fs pulses with an average power of up to 1.02 W and a repetition rate of 40.6 MHz at 1.56 μm (corresponding to an energy of 25.1 nJ). The pulse compressor in the CPA system is based on a hollow core photonic crystal fiber which is directly butt-coupled to the silica fiber. A mismatched negative third-order dispersion is used to compensate the accumulated nonlinear phase shift in the amplification process for the first time, resulting in the generation of sub-400 fs pulses from an all-fiber Watt-level Er-doped CPA system. Our system architecture offers a possibility for ultrashort pulse generation from all-fiber Er-doped CPA lasers.