Development of multi-kW Coherently Combined Fibre Master Oscillator Power Amplifiers

提出了Yb光纤主振荡器功率放大器（MOPA）的发展，使功率从几千瓦到大于20千瓦的相干组合激光束阵列。这符合列奥纳多的战略计划，为一系列国防应用提供新颖而强大的激光技术。要达到对目标的最高辐照度，将需要开发和演示千瓦级光纤MOPA，其波长为1米，具有最高的效率和对影响空间和时间相干性的激光参数的最严格控制。在广泛的环境条件下进行被动和主动相位控制的最先进技术将是工作的一个关键主题。为在最终的系统中组合大量的纤维MOPA（N > 10）奠定了基础，该系统对极端环境条件具有鲁棒性。此外，这项工作将包括通过应用神经网络开发先进的相位传感和自适应控制的范围。光纤MOPA的封装对于优化放大器性能也很重要，因此提出了先进的制造和组装技术，并得到高功率光纤激光器建模和仿真的支持。该项目将把最先进的光纤放大器提升到最高效率的数千瓦功率水平。通过应用列奥纳多和赫瑞瓦特大学现有的最新光纤组件、传感和计量技术，将新奇嵌入到项目中。放大器将利用最新的先进封装方法，一个例子是使用玻璃-金属结合的光纤准直光束传输组件，如埃里奥特瓦特大学开发的。该提案包括在最先进的相干组合激光系统中的神经网络的新应用。

Development of Yb fibre Master Oscillator Power Amplifiers (MOPAs) is proposed, to enable power scaling from multi-kW to greater than 20 kW in coherently combined laser beam arrays. This aligns with a Leonardo strategic plan to deliver novel and robust laser technology for a range of defense applications. Achieving the highest irradiance on target will be underpinned by the development and demonstration of kW-level fibre MOPAs, at 1m wavelength, with the highest efficiency and tightest control of laser parameters affecting spatial and temporal coherence.State of the art techniques for passive and active phase control under a wide range of environmental conditions will be a key theme of the work, laying the foundations for combining large numbers of fibre MOPAs (N > 10) in an eventual system which is robust against extreme environmental conditions. Further to this, the work will include scope for the development of advanced, phase sensing and adaptive control via the application of neural networks. Packaging of fibre MOPAs is also of importance for optimum amplifier performance and so advanced manufacturing and assembly techniques are proposed, supported by high-power fibre laser modelling and simulation.The project will advance state-of-the-art fibre amplifiers to multi-kW levels of power with the highest efficiency. Novelty is embedded within the project by the application of the latest fibre components, sensing and metrology techniques available within Leonardo and Heriot-Watt University. The amplifiers will exploit the latest advanced packaging methods and one example is the use of glass-to-metal bonding of fibre-collimated beam delivery assemblies, as developed at Heriot Watt University. The proposal includes a new application for neural networks within state-of-the-art coherently combined laser systems.