Fiber Optic Transmission

Fiber optic technology is a major reason for the feasibility of residential broadband. More than metal wires, fiber has the carrying capacity to supply high-speed services to millions of homes. Fiber optic cables are made from very clear glass, much more transparent than window glass. Fiber technology uses lightwave signals to transmit data, whereas metal wire uses electro-magnetic signals. The clarity of the glass permits the distribution of lightwave impulses for possibly hundreds of miles.

Coding uses simple On/Off keying. A transmitter indicates a binary 1 by turning on the light. If the light is off, it indicates a binary 0. Light is perceptible when the receptor senses photons. More complicated coding schemes, such as amplitude modulation, are possible, but simple OOK works with current technologies for digital transmission.