What is the composition material of optical fiber connector Mainly PEI, polyetherimide, amber transparent solid, without any addition, it has inherent flame retardancy and low smoke. The combustion grade is UL94-V-0, and the density is 1. Optical fiber cables are made up of three components: the core, the cladding, and the buffer. Core: this is the central part of the cable through which light travels. The choice of material is an engineering decision driven by the need to. Fiber optic cables are designed to provide high-speed, no-signal-loss, and EMI-free communication in telecommunication, powergrid, datacenter, broadband, and industrial applications.