Tunable mid-infrared source from an ultrafast two-color Yb:fiber chirped-pulse amplifier

We present a tunable, ultrafast, mid-infrared source based on difference frequency between 16 μm and 20 μm from an ultrafast, two-color Yb:fiber chirped-pulse amplifier. We have recorded an average power of 1.5 mW at ∼18  μm. We have improved the output power after the pre-amplifier by one order of magnitude. We present the simulation and experimental results to the pre-amplifier.