Standard high-performance fiber optic data cables do not contain copper elements. Eliminating copper delivers significant performance advantages: Immunity to electromagnetic interference (EMI): Light-based signaling prevents. Fiber optic cables are built with a silica glass fiber core, about the width of a human hair. It transmits data via light, by allowing it to bounce back and forth down the length of the glass core, while a glass cladding surrounds the core and ensures the light is retained within it. This makes them ideal for long distance communication. You may also want to know: Are Bing and Yahoo the Same? ·.