High Repetition Rate, Wavelength-Tunable Mid-IR Source Driven by ps-Pulses from a Ho:YLF Amplifier at 2 μm

The generation of ultrashort pulses in the mid-infrared (mid-IR) spectral region is highly demanded for a multitude of applications such as spectroscopy, materials processing, or biomolecular and chemical sensing. For many of the aforementioned applications a high pulse repetition frequency (PRF) is desirable, since it reduces measurement time and improves spectroscopic signal-to-noise ratio. However, most of the ultrafast mid-IR sources are limited to a PRF below 10 kHz as they rely on regenerative amplifier-based pump sources for optical parametric chirped pulse amplification (OPCPA) [1–3]. The herein applied Pockels cell represents a bottleneck for PRF tuning usually below 10 kHz. Just recently, we presented a 2-μm, sub-10 ps pulse laser system with millijoule-level pulse energy, which is in principle not limited by the PRF [4]. This laser system benefits from its simplified, compact CPA-free architecture and high efficiency.