Ultrashort pulse laser welding of silicon carbide (4H-SiC) to glasses and crystals

We report the successful application of ultra-short pulse (USP) laser welding using a low numerical aperture (NA ∼0.02) beam delivery system coupled into a scanning galvanometer to bond 4H-silicon carbide (4H-SiC) to BK7, fused silica, and crystalline quartz. 4H-SiC is known for its exceptional thermomechanical properties, making it an ideal candidate for demanding high-temperature and pressure applications. This study is evaluating the impacts of CTE mismatch between the dissimilar material combinations on the weldability and survivability of the assemblies. Additionally, we evaluated the thermal and humidity cycling survivability of the welded assemblies, demonstrating the robustness of the joints under environmental stress.