Long seed, short pump: converting Yb-doped laser radiation to multi-μJ few-cycle pulses tunable through 2.5-15 μm

We present a setup for generating broadband (up to 1050 cm(-1)) and broadly tunable (2.5-15 mu m) mid-infrared pulses using an Yb-doped femtosecond laser as the pump source. Our scheme, comprising two parametric amplifiers and a mixing stage, exploits favorable group velocity matching conditions in GaSe pumped at 2 mu m to directly produce sub-70 fs pulses throughout the tuning range without any additional dispersion compensation, while 30-50 fs pulse durations are achieved with simple dispersion compensation by propagation through thin bulk media. The generated pulses have sub-1% short- and long-term energy noise, as well as stable spectral parameters, while delivering 0.5-2 W average mid-IR power. We expect the source to be useful for various spectroscopic applications in the mid-IR. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement