Loss Mechanisms and Measurements in Clad Glass Fibers and Bulk Glass

Abstract

Optical-loss mechanisms and transmission losses were investigated in clad glass fibers and in the bulk glass from which they were drawn. Measurements of the total losses, absorption losses, and scattering losses in both the fibers and in the bulk materials are presented and compared. Photomicrographs of scattered light were made at 90° with 0.6328-μm laser light propagating in the fiber core. These revealed the presence of an extremely large number of discrete light-scattering centers, both in the core and in the cladding. Similar photomicrographs of the bulk materials also show the presence of discrete scattering centers. Scattering centers have also been observed by means of an electron microscope; they have been shown to be crystalline, by both electron diffraction and x-ray diffraction.