Glasses

Attention is focused on the materials and fabrication techniques for glass planar waveguides and on fluoride, chalcogenide, and other specialty glass fibers. Glass optical waveguides are primarily used as passive transmission links in optical communication systems. Other, smaller volume, passive applications include integrated optics, spectroscopy, pyrometry, chemical sensors, and laser power delivery systems. In the latter applications a much wider range of materials and fabrication techniques are employed than for high-silica communication fibers. Two general approaches have been implemented in their fabrication: substrate modification techniques, in which core regions are created by subsurface compositional or structural modifications to glass substrates, and deposition techniques in which as many as three distinct glass layers are deposited sequentially on top of a substrate. The elemental chalcogens exhibit glass-forming ability, but only binary, ternary, and higher order systems incorporating non-chalcogen elements, are of practical interest for fiber fabrication.