Ultra-short pulsed laser welding - an industrially-relevant manufacturing tool for bonding IR and visible optical materials

将光学材料（玻璃、晶体）与其他光学或结构材料（金属、陶瓷）粘合是许多光学设备的关键制造挑战，我们的工业合作伙伴对此有明确的阐述。我们的解决方案是使用超短脉冲激光焊接工艺，该工艺已显示出巨大的前景，但目前需要对每种新材料组合和几何形状进行数月甚至数年的详细实验。因此，目前的应用仅限于由硼硅酸盐玻璃或石英焊接到铝合金和不锈钢上制成的组件，典型尺寸为10 mm。在该项目中，我们的目标是将工艺扩展到材料（包括重要的IR材料）和形状的新组合。为了实现这一目标，该项目将采取多管齐下的方法：（i）创建快速工艺优化所必需的建模和传感工具;（ii）基于新兴的2微米波长技术设计新的优化激光源，开创红外光学材料的焊接工艺;（iii）研究设计界面和焊缝/接头几何形状的概念，以减少两种材料的不同热性能的影响;以及（iv）研究用于较大部件的可缩放焊接方法，例如连续曲折图案和动态夹紧。最后，我们将进行一系列的原理验证实验，以确定该工艺对各种材料组合的适用性，并针对我们的工业合作伙伴的应用。我们的制造研究计划符合我们的工业合作伙伴的利益，以及激光材料相互作用知识，工艺理解和工艺控制的学术驱动因素。我们的最终目标是将这种焊接工艺发展成为一种真正灵活和通用的解决方案，用于在各种规模上连接光学材料和结构材料。

Bonding optical materials (glasses, crystals) to other optical or structural materials (metals, ceramics) is a key manufacturing challenge for many optical devices, as clearly articulated by our industrial partners. Our solution is to use an ultra-short pulsed laser welding process that has shown great promise but currently requires many months or even years of detailed experiments for each new material combination and geometry. Hence applications are currently limited to components made from borosilicate glasses or quartz welded to aluminium alloys and stainless steel, of typical dimension 10 mm. In this project our drive is to extend the process to new combinations of materials (including important IR materials) and shapes. To achieve this, the project will take a multi-pronged approach: (i) to create the modelling and sensing tools essential for rapid process optimisation; (ii) to engineer a new optimised laser source based on emerging 2 micron wavelength technologies, pioneering the welding process for IR optical materials; (iii) to research concepts for engineering the interface and weld/joint geometry to reduce the impact of differential thermal properties of the two materials; and (iv) to investigate scaleable welding approaches for larger parts e.g. continuous meander patterns and dynamic clamping. Finally, we will undertake a series of proof-of-principle experiments to determine the suitability of the process with a wide range of material combinations, directed towards our industrial partners' applications.Our programme of manufacturing research is aligned with the interests of our industrial collaborators, together with the academic drivers of laser material interaction knowledge, process understanding and process control. Our ultimate goal is to develop this welding process into a truly flexible and generic solution for joining optical to structural materials at a range of scales.