Properties of plastic optical fibers

Experimental and theoretical studies of the optical properties of large-core step-index plastic optical fibers (POF's) and graded-index POF's are reported. A set of criteria and analyses of physical parameters is developed in the context of major issues of POF applications in short-distance communication systems. Analyses are presented to show how the measured POF optical attenuation affects the overall performance in wavelength-division multiplexing and how the use of perfluorinated polymers can overcome limitations inherent in current POF materials. Results of POF optical bandwidth measurements by direct picosecond time-domain methods are reported, and their relationship to refractive-index profiles are theoretically analyzed by the WKB and finite-element methods. Two high-resolution optical techniques of refracted near-field and transverse interferometric methods are presented and are used to measure the index profiles of large-core POF's. Results reveal that the index profile of currently available graded-index POF is not parabolic, which significantly limits its bandwidth compared with that of a true parabolic graded-index profile. (C) 1998 Optical Society of America.