OPTICAL-FIBER PROCESSING - SCIENCE AND TECHNOLOGY

In recent years significant advances have been made in materials chara cterization and process development in optical fibers. This paper desc ribes the important advances in defect characterization, processing an d properties of hermetic fibers, and fabrication of fiber amplifiers. The important defects in optical fibers are those associated with the silica-glass network and the germanium dopant in affecting the short-w avelength properties, and those associated with OH and H-2 contaminant s in causing optical absorption near the communication wavelengths. Ch aracterization of the photo-induced defects has provided fundamental u nderstanding in diffraction grating formation and second harmonic gene ration in fiber devices. Hermetic coatings have been deposited on opti cal fibers, and hermetic fibers show remarkable improvements in both m echanical and hydrogen reliabilities. Material properties of glass hos ts and rare-earth dopants as well as the fiber designs and preform pro cessing are shown to have significant impacts on the device performanc e of fiber amplifiers.