Interfacial Bonding Strength of Multilayer Metal-Coated Optical Fiber

Multilayer metal-coated optical fibers were fabricated by respectively depositing a silver (Ag) film and a titanium (Ti) film on bare optical fibers by magnetron sputtering, and subsequently a nickel (Ni) coating was prepared on the film by electroplating. The interfacial bonding strength between the metallic coating and optical fiber was measured by using single-fiber push-out tests. The interfacial morphology and elements were analyzed, as well as the influence of various coating materials and electroplating conditions on the bonding strength. The experimental results show that the sputtered metallic films remained intact, and the failure location appeared at the interface between the metallic coating and optical fiber. The interfacial bonding between Ti film and optical fiber is stronger than that between Ag film and optical fiber. The interfacial bonding strength between the metallic coating and optical fiber for the nickel coating electroplated at a higher temperature and a lower current density is higher.