In-situ Measurements with Fibre Bragg Gratings embedded in Stainless Steel

Metal clad single mode optical fibres containing high reflectivity Bragg gratings are successfully embedded into stainless steel components using bespoke laser based additive manufacturing technology. Temperature cycling of the embedded sensor demonstrates the ability of gratings to survive the embedding process, and act as temperature or strain sensors. At extreme temperatures up to 500 degrees C, discontinuities in the gratings response are observed and these have been attributed to possible delamination issues at the interface between glass fiber and the surrounding metal.