A novel approach to manufacturing lasers using ultrafast laser welding


Ultrafast (picosecond, femtosecond) pulsed lasers have enabled welding processes to directly join highly dissimilar materials combinations (e.g. glass and metal). Such welding was previously thought to be impossible due to the very large difference in thermal expansion coefficients and hence thermally-induced cracking.  From initial proof-of-concept experiments, Heriot-Watt have been working with Leonardo MW to convert the process into a robust manufacturing process, with a particular focus on welding borosilicate glass to Aluminium alloy Al6082.

This industry-sponsored PhD project will build on this earlier research, focused on the application of such processes to the manufacture of a laser system.  The use of this technology has important advantages, in particular removing the requirement for adhesives within the laser cavity.  Outgassing from adhesives can result in optical damage since the outgassed material can deposit on optical surfaces, and hence reduce their optical damage threshold.  The proposed welding approach will also help to convert laser manufacturing from a skilled assembly process to a much lower cost automated manufacturing process.

The project will involve:

Extending the process to different materials and material combinations e.g. Nd:YAG to aluminium alloy Evaluating stress within an optic fixed in place in this way, and the impact this will have on laser performance Developing surface structures (e.g. laser patterned surfaces) to minimise stress Develop new design strategies for future laser systems to utilise this new manufacturing technology.


Heriot-Watt is based in a modern environment on the outskirts of Edinburgh, with excellent transport links to the centre of one of Europe’s most exciting cities. Heriot-Watt hosts the EPSRC Centre for Doctoral Training in Applied Photonics, cementing Heriot-Watt’s reputation as a centre of excellence in photonics, and providing PhD students with an even more attractive environment for study, as well as enhanced training opportunities.

Heriot-Watt Institute of Photonics and Quantum Sciences (IPAQS)

IPAQS is a thriving environment for PhD research, having a total of 160 academics, postdocs, PhD and EngD students working full-time in the general photonics field. It’s a friendly collaborative environment where staff and students freely interact -- not least at Friday morning coffee and donut sessions.

Funding Notes

This 3.5-year project is funded by the EPSRC and Leonardo as a ‘CASE conversion.’ The funding covers the student stipend (avg £17,600 per annum), fees, incidental costs and conference travel. Funding is available only to UK residents.


Please send a CV including 2 references to Prof. Duncan Hand and Prof. Daniel Esser.