Short mid-infrared watt-level all-fiber nonlinear pulse compressor above 100-MHz pulse repetition rate.

We firstly report a 2-µm all-fiber nonlinear pulse compressor based on two pieces of normal dispersion fiber (NDF), which enables a high-power scaling ability of watt-level and a high pulse compression ratio of 13.7. With the NDF-based all-fiber nonlinear pulse compressor, the 450-fs laser pulses with a repetition rate of 101.4 MHz are compressed to 35.1 fs, corresponding to a 5.2 optical oscillation cycle at the 2-µm wavelength region. The output average power reaches 1.28 W, which is believed to be the highest value never achieved from the previous 2-µm all-fiber nonlinear pulse compressors with a high pulse repetition rate above 100 MHz. The dynamic evolution of the ultrafast pulse inside the all-fiber nonlinear pulse compressor is numerically analyzed, matching well with the experimental results. [ABSTRACT FROM AUTHOR]