Optical Diffraction Profiles of Single Fibers

The light-scattering properties of single fibers of wool, hair, and jute and filaments of nylon, terylene, and glass have been studied by scanning along their lengths with a He-Ne laser beam. The light-scattering profiles of the natural fibers suggest uniformity in the optical properties of the fiber materials and are, therefore, closely related to the geometry of the fibers. The optical properties of nylon and terylene, on the other hand, are observed to be very nonuniform along the filament. This nonuniformity is attributed to variations in (a) the orientation of birefringent domains of the filament material with the filament axis and (b) the crystallinity or packing density of the material. Because of this lack of uni formity it is not possible to define optical and dimensional parameters that are constants for these filaments from light- scattering data over any appreciable length (Ca > 0.5 mm). Glass fibers have light-scattering properties that vary along their length in a way that is determined by their method of formation.