The publication “Laser Metal Deposition Based Embedding of Optical Fibres” explores how optical sensing can be brought directly beneath functional metal surfaces. It investigates how laser metal deposition (LMD) can embed fibres without damaging them, a task made difficult by the high temperatures and stresses central to the process.

Tackling the core challenge

Optical fibres offer precise temperature and strain measurements but embedding them in metal components is risky if heat is not tightly controlled. The paper focuses on identifying LMD parameters that minimise thermal impact while maintaining weld quality. By adjusting power levels, spot size and scan speed, the researchers develop a parameter set that reduces the heat-affected zone and preserves fibre functionality. Ceramic sleeves and a protective metal strip further shield the fibre during deposition.

Testing the method in practice

A series of experiments on structural and stainless-steel sheets was used to determine suitable settings. Once optimised values were found, the team embedded a single-mode fibre inside a machined groove and deposited twelve LMD layers over it, pausing between layers to allow cooling. Visual inspection and micro-CT imaging showed no structural damage to the fibre and only minor sleeve deformation. Light transmission tests confirmed that the optical pathway remained intact.

Building foundations for embedded sensing

The results demonstrate that LMD can reliably embed optical fibres under the right conditions. This enables metal parts to host sensing capability directly beneath their surfaces, supporting future applications in aerospace, tooling, automotive and structural monitoring. Further work is needed to understand optical performance changes after embedding, but the study offers a practical baseline for researchers and industry.