Towards High-Power Densely Step-Tunable Mid-Infrared Fiber Source From 4.27 to 4.43 µm in CO_2-Filled Anti-Resonant Hollow-Core Silica Fibers

Soft-glass fiber lasers have attracted lots of attentions as they are most likely to achieve compact, stable, and highly efficient mid-infrared emission, which has unique applications in many fields. However, due to the immature manufacturing technique of soft glass fibers and the limited types of doped rear-earth, laser power enhancing and wavelength expansion beyond 4 μm are greatly restricted. ...