Plastic fiber optics. II: loss measurements and loss mechanisms

Transmission loss in plastic optical fibers was investigated for axial, small numerical aperture input. The loss coefficient alpha was determined as a function of wavelength lambda by varying sample length and using filters. More extensive information on alpha(lambda) was obtained by use of a monochromator with transmission at a particular lambda standardized by independent measurement. Measurement in white light of scattered intensity as a function of position along a fiber yielded alpha and an estimate of scattering power. Analyses of the scattering data and the variation of alpha with lambda suggest that scattering is the principal loss mechanism.