Generation of 8–20 μm Mid-Infrared Ultrashort Femtosecond Laser Pulses via Difference Frequency Generation

Mid-infrared (MIR) ultrashort laser pulses have a wide range of applications in the fields environmental monitoring, medicine, food quality control, strong-field physics, attosecond science, and some other aspects. Recent years seen great developments MIR technologies. Traditional solid-state fiber lasers focus on research short-wavelength region. However, due to limitation gain medium, they still cannot cover long-wavelength region from 8 20 µm. This paper summarizes 8–20 μm ultrafast generation via difference frequency (DFG) reviews related theoretical models. Finally, feasibility power scaling by nonlinear-amplification DFG methods for measuring DFG-based are analyzed author’s perspective.