Fiber-optic cables are made of strands of glass or plastic fibers that carry data in the form of light signals. The cable core is added. There are three traditional basic core constructions of optical fibre cables: In addition to the three traditional basic constructions, there is also a more recently developed flexible loose tube construction. The optical fibers are then laid in the tube Performance: Central tube optical cables have good lightweight, small diameter, and low cost characteristics, making them. Photo: Light pipe: fiber optics means sending light beams down thin strands of plastic or glass by making them bounce repeatedly off the walls. Some conductors are a single, solid wire of copper or aluminium, while others are made up of individual wires through a process called “stranding”. This involves twisting the wires together to form a single.