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

Automated summary

This paper summarizes the developments in mid-infrared (MIR) ultrafast laser generation and discusses the methods and theoretical models for generating 8-20 μm MIR ultrafast laser pulses via difference frequency generation (DFG). Furthermore, the feasibility of MIR power scaling using nonlinear-amplification DFG and methods for measuring the power of DFG-based MIR are analyzed from the author's perspective.