Fiber optic refers to the abbreviation of optical fiber. Fiber optic communication is a type of communication that uses light waves as information carriers and optical fibers as transmission media. From a principle perspective, the basic elements of fiber optic communication are fiber optic, light source, and light detector. In addition to being classified based on manufacturing processes, material composition, and optical characteristics, fiber optics are also classified based on their applications, namely communication fibers and sensor fibers. Transmission medium fibers are further divided into general-purpose and special-purpose. Functional device fibers refer to fibers used for functions such as amplifying, shaping, dividing, doubling, modulating, and oscillating light waves, and they often appear in the form of certain functional devices.
Fiber optic communication is a communication method that uses light waves as carriers and optical fibers as transmission media to transmit information from one place to another. It is known as "wired" optical communication. Today, fiber optics have become the main transmission method in global communication due to their wide transmission bandwidth, high resistance to interference, and low signal attenuation, which are far superior to cable and microwave communication.
Fiber optic communication has a wide range of applications. It is mainly used for local telephone trunk lines, where the advantages of fiber optic communication can be fully utilized to gradually replace cables and gain extensive applications. It is also used for long-distance trunk communication, which used to rely mainly on cables, microwaves, and satellite communication. Fiber optic communication has gradually been used and developed into a globally dominant bit transmission method. It is used in global communication networks and various countries' public telecommunication networks (such as China's national trunk lines, second-level trunk lines in provinces, and branch lines below the county level). It is also used for high-quality color TV transmission, industrial production site monitoring and scheduling, traffic monitoring and control, urban cable television networks, community antenna television (CATV) systems, fiber optic local area networks, and in environments such as aircraft, ships, mines, power departments, and military and corrosive and radioactive environments.
Fiber optic transmission systems mainly consist of optical transmitters, optical receivers, optical cable transmission lines, optical repeaters, and various passive optical devices. To achieve communication, baseband signals must be processed by the electrical terminal equipment and sent to the fiber optic transmission system for communication.
It is suitable for fiber optic analog communication systems, fiber optic digital communication systems, and data communication systems. In fiber optic analog communication systems, electrical signal processing refers to amplification and pre-modulation of baseband signals, while electrical signal reverse processing refers to the inverse process of transmission end processing, such as demodulation and amplification. In fiber optic digital communication systems, electrical signal processing refers to amplification, sampling, quantization, pulse code modulation (PCM), and line coding processing, while electrical signal reverse processing is the reverse process of transmission end processing. For data fiber optic communication, electrical signal processing mainly involves signal amplification, and unlike digital communication systems, it does not require code transformation.