High-Strength Fiber-Optic Waveguide

The goal of this program is to develop procedures for fabricating continuous 10-km lengths of low-loss fiber-optical waveguide that will exhibit survival probabilities in excess of 95 at 2 strain for 10-year service in high-humidity environments. The effort centers around a unique procedure developed at HRL for hermetically sealing the glass fiber in a metallic jacket. This hermetic jacket provides substantial protection to the glass fiber surface from the deleterious effects of moisture and other environmental contaminants that cause static fatigue i.e., a reduction in fiber strength with time. Test results on recently prepared glass fibers evaluated in a humid environment under high stress indicate that survival times are at least five orders of magnitude longer for the Hughes aluminum-coated fibers than for state-of-the-art polymer- coated fibers. In the third quarter of the program, investigation of a variety of processing parameters that affect both the strength and optical characteristics of Al-clad silica was continued.