Improving the output performance from mid-infrared fibre lasers

Recent progress in the field of mid-infrared fibre lasers is reviewed with a special emphasis on the various methods that have been directed towards the augmenting of both the efficiency and output power that is produced from fibre lasers that emit in the 2-3 μm region of the spectrum. Diode lasers, Yb³⁺-doped silica fibre lasers, Tm³⁺-doped silica fibre lasers and Raman fibre lasers are shown to be useful pump sources for mid-infrared fibre lasers. The various dopants in both single and co-doped combinations that are useful for the generation of mid-infrared output are also reviewed. Possible areas of future research that are aimed at extending the wavelength range of high power mid-infrared fibre lasers are discussed.