High power mid-infrared lasers

对在中红外光谱区(3微米-5微米)发射的高功率激光光源的需求越来越大，以满足材料激光加工、医学、传感、国防和光通信等领域越来越多的应用的需要。此外，将工作在1微米波段的传统掺Yb光纤激光器转移到2微米波段可以获得显著的功率比例优势。访问中红外波长区域的标准方法是通过近红外固体激光器的非线性频率转换。不幸的是，由于激光介质中产生的废热的影响，随着功率水平的增加，该方法具有许多缺点，因此，功率水平受到限制。该项目将把工作在2微米波段的包层泵浦Tu和Ho光纤激光器的功率缩放优势与一些新的非线性频率转换方案结合起来，在连续波和脉冲工作状态下产生非常高功率水平的中红外输出。如果成功，该项目将为新一代中红外光源铺平道路，该光源具有操作波长的灵活性，其性能水平远远超过当前最先进的水平。

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.