The application field of optical fiber communication is very extensive, mainly used in local telephone trunk lines. The advantages of optical fiber communication can be brought into full play here, gradually replacing cables and being widely used. It is also used for long-distance trunk communication in the past, which mainly relied on cables, microwaves, and satellite communications. Now it is gradually using optical fiber communication and has formed a globally dominant bit transmission method; it is used in global communication networks and public telecommunication networks in various countries (such as China’s national first It is also used for high-quality color television transmission, industrial production site monitoring and dispatching, traffic monitoring and control command, urban cable television network, and common antenna (CATV) system. It is used in optical fiber local area network and other such as aircraft, spacecraft, ships, underground mines, electric power departments, military, corrosion and radiation, etc.
The optical fiber transmission system is mainly composed of: optical transmitter, optical receiver, optical cable transmission line, optical repeater and various passive optical devices. To achieve communication, the baseband signal must be processed by the electrical terminal and sent to the optical fiber transmission system to complete the communication process.
It is suitable for optical fiber analog communication system, but also suitable for optical fiber digital communication system and data communication system. 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 optical fiber digital communication systems, electrical signal processing refers to the amplification, sampling, and quantization of baseband signals, namely pulse code modulation (PCM) and line code coding 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.
