ABSTRACT
Currently available plastic optical fibers have transmission losses of more than 100 dB/km and very low bandwidth-distance products of a few MHz km, owing to their large core diameter, high numerical aperture, and step index profiles. Three different techniques have been used to fabricate plastic optical fibers: extrusion, preform drawing, and tube filling. Tube filling is a process which enables plastic optical fibers to be fabricated with thermosetting (cross-linked) polymer cores. In this process a polymerizable liquid, (e.g., one or more monomers or an oligomeric or polymeric casting resin) is injected into an extruded, low refractive index thermoplastic (e.g., perfluorinated ethylene-propylene copolymer) tube and allowed to polymerize (cross-link), usually by thermal means. The tube-filling process has been used to make environmentally resistant plastic optical fibers. The automotive underhood environment is one of the most environmentally demanding and economically attractive application areas for implementation of plastic optical fiber data transmission links.
