High-Power MIR Lasers for Strong Field Experiments

While most strong-field experiments have traditionally been restricted to the near-infrared (NIR) regime (0.8–1 µm), theoretical models suggest that many physical processes scale more favorably at longer wavelengths [1]. Driven by this potential, high-power short-wave and mid-infrared (MIR) lasers have recently emerged as indispensable tools for investigating wavelength-scaling laws across strong-field atomic, molecular, and plasma physics. We have demonstrated a femtosecond chirped-pulse amplifier (CPA) leveraging Cr:ZnSe and Fe:ZnSe gain media [2]. To achieve few-cycle pulses, the CPA output was spectrally broadened in a gas-filled hollow-core fiber (HCF) and subsequently compressed using bulk materials for dispersion compensation [3]. Furthermore, we developed a compact, high-repetition-rate optical parametric chirped-pulse amplifier (OPCPA) based on ZGP crystals, pumped by a 2-µm CPA system [4]. Given current developmental trajectories, the peak power of MIR femtosecond lasers is projected to reach the terawatt (TW) level in the near future, opening new frontiers for relativistic plasma experiments.