High power mid-infrared lasers

There is increasing demand for high power laser sources emitting in the mid-infrared spectral region (3 micrometres - 5 micrometres) to serve the needs of a growing number of applications in areas such as laser processing of materials, medicine, sensing, defence and optical communications. Moreover, significant power scaling advantages can be gained by moving from traditional ytterbium-doped fibre lasers operating in the one-micron band to the two-micron band.

The standard method of accessing the mid-infrared wavelength region is via nonlinear frequency conversion of near-infrared solid-state lasers. Unfortunately, this approach has a number of shortcomings as power levels are increased, due to the effects of waste heat generated in the laser medium, and, as a consequence, power levels are limited. This project will combine the power-scaling advantages of cladding-pumped thulium and holmium fibre lasers operating in the two-micron band with a number of novel nonlinear frequency conversion schemes to generate mid-infrared output at very high power levels in continuous-wave and pulsed operating regimes. If successful, this project will pave the way for a new generation of mid-infrared sources with flexibility in operating wavelength boasting levels of performance well beyond the current state-of-the-art.