Broadly tunable mid-infrared femtosecond pulses directly generated by an optical parametric amplifier

We introduce an optical parametric amplifier, pumped by amplified femtosecond Yb:KGW laser, which directly generates broadly tunable mid-infrared (MIR) pulses, covering the whole vibrational spectrum from 3 to 10 µm. The avoidance of traditional difference-frequency generation stage access MIR range simplifies setup while enabling high conversion efficiencies. two-stage design employs in second either periodically poled lithium niobate, optimized for CH/OH stretching region (3-5 µm) or LiGaS 2 , allows extending tunability fingerprint (up µm). anticipate applications this versatile source ultrafast spectroscopy and infrared microscopy.