Jacketing of Optical Fibers with Ordered Thermotropic Liquid Crystal Polyesters

Abstract

Thermotropic liquid crystal polyesters (LCPs), based on improved polyethylene terephthalate (PET) and para-hydroxybenzoic acid (PHB), are investigated as a secondary jacketing material for enclosing optical fibers. Because of shear- and deformation-induced molecular orientations produced during extrusion, the newly developed LCPs exhibit low thermal expansion coefficients and high Young's moduli. As a result, the LCP-jacketed optical fibers show small loss increases in the −60°C to 80°C temperature range and high lateral load resistance, compared with conventional nylon-jacketed optical fibers. Furthermore, the low melt viscosity and significantly low thermal shrinkage allow us to coat the LCPs on the optical fibers at high speeds above 300 m/min.