High-temperature coatings for optical fiber

A major factor that determines the reliability of silica optical fibers in high temperature environments is the nature of the coating material and process. We have demonstrated coating silica fibers using dc planar magnetron sputter deposition. A unique feature of this method is the ability to hermetically coat fiber with high temperature metals that are impossible to deposit by conventional fiber coating processes. Such coatings are deposited uniformly in thickness with relatively high efficiencies. The results obtained with adherent, pinhole-free copper coatings indicate that the process is suitable for on-line coating of optical fibers as they are drawn.