Fiber Optic Cables

Fiber optic cables use glass or plastic to transmit light along the length of the cable. They transmit light modulated to carry information such as television, voice, and data. Compared to wire cables, they provide higher bandwidth and capacity, much lower loss, and are less susceptible to interference.

The fiber is one or more strands of glass that are extremely thin. The core of the strand carries the signal. The layer surrounding the core is called the cladding. It reflects light inward to the core to avoid signal loss. There is also a coating around the fiber to protect it from the elements. The transmitting light is generated by small lasers or light-emitting diodes (LED). 

Fiber optic cables are used for long-distance connections across cities, countries, and oceans. They are also used to carry Internet services within neighborhoods and into homes. There are direct fiber connections, often from the central office to a business. There is also shared fiber that routes the signal close to several customers and then splits the signal. 

One advantage of fiber optic cables is their much higher speeds than coaxial cables. Fiber can reach speeds of 2,000 Mbps versus 1,000 Mbps for coaxial cable. Fiber is also free of interference and cross-talk between fibers in a bundle.