Mechanical reliability of metallized optical fiber for hermetic terminations

Hermetic packaging requirements for high-reliability fiber-optic devices can be met through the use of solder-sealed fibre penetrations. Local metallization of the fiber surface facilitates soldering but also modifies the fiber´s strength and fatigue properties. A significant body of research addresses the properties of fibers coated with metal during fiber drawing, but the mechanical properties of fibers locally metallized after drawing have not been discussed. These properties were evaluated by means of dynamic fatigue tensile testing for fibres having a multilayer metallization applied by a vacuum deposition process. The results show that fiber strength reduction resulting from metallization is compensated by an increased resistance to static fatigue. Use of the results in reliability assurance is discussed