An eye-safe, high-repetition rate single-mode femtosecond chirped pulse amplification system at 1560 nm

In this work we demonstrate a high-power, high-repetition rate chirped pulse amplification system operating at 1560?nm center wavelength. The system consists of a mode-locked Er-fiber oscillator, a grating-based pulse stretcher, a two-stage amplifier and a grating compressor. The system provides over 2.5?W of average output power with nearly transform limited, linearly polarized 390?fs pulses and 12.6?nJ pulse energy at 200?MHz repetition rate. The whole design is based on single-mode fibers, which allows excellent beam quality to be maintained.