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

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.