The optical fiber communication system is a communication system that uses light as the carrier wave, uses extremely thin glass to draw extremely thin optical fibers as the transmission medium, and uses light to transmit information through photoelectric conversion. With the rapid development of the international Internet business and communications industry, informatization has greatly promoted the world’s productivity and human society. As one of the main technical pillars of informatization, optical fiber communication is bound to become the most important strategic industry in the 21st century.
1. The amount of information that can be transmitted per unit time is large. In the early 1990s, the information rate of the practical level of optical fiber communication was 2.488 Gbit/s, that is, a pair of single-mode optical fibers can open 35,000 telephones at the same time, and it is still developing rapidly.
2. The price is low. The construction cost of optical fiber communication decreases with the increase in the number of uses.
3. Small size and light weight. Construction and maintenance are more convenient.
4. Less metal is used. Its anti-electromagnetic interference, strong anti-radiation, good confidentiality and so on.
The application field of the fibre optical communication system is very extensive, mainly used in the local telephone trunk line. The advantages of optical fiber communication can be brought into full play here. It gradually replaces cables and is widely used. In the past, long-distance trunk line communications mainly relied on cable, microwave, and satellite communications. Now the use of optical fiber communication has become the dominant bit transmission method in the world; The general system of optical fiber communication is used in global communication networks and public telecommunications networks in various countries; it is also used in high-quality color television transmission, industrial production site monitoring and dispatching, traffic monitoring, control and command, Urban cable television network, common antenna (CATV) system; used in optical fiber local area networks and other such as aircraft, spacecraft, ships, underground mines, power departments, military, corrosion and radiation, etc.
It is suitable for optical fiber analog communication systems, as well as optical fiber digital communication systems and data communication systems. In an optical fiber analog communication system, electrical signal processing refers to processing such as amplification and pre-modulation of baseband signals, while electrical signal reverse processing is the inverse process of originating processing, that is, processing such as demodulation and amplification. In general optical fiber communication systems, electrical signal processing refers to amplifying, sampling, and quantizing baseband signals, that is, pulse code modulation (PCM) and line code encoding processing, etc., and electrical signal reverse processing is also the inverse process of origination. For data optical fiber communication, electrical signal processing mainly includes amplifying the signal, which is different from the digital communication system in that it does not require code conversion.