Review on recent progress on mid-infrared fiber lasers

We present review on recent progress on mid-infrared fiber lasers. The relevant glass fiber host materials and different kinds of doped rare-earth ions are introduced. Lasers operating from 1.9 to 3 ??m in the rare-earth ions Tm³⁺, Ho³⁺, Er³⁺, and Dy³⁺ in the recent two years are discussed. Three interesting research issues, i.e., supercontinuum generation based on mid-infrared fiber laser, mid-infrared Raman fiber laser, and coherent beam combining in the mid-infrared wavelength band are classified and analyzed. Some discussions and prospective predictions are proposed at the end of this paper.