Application fields of optical fiber communication
The application field of optical fiber communication is very wide, which is mainly used in local telephone trunk line. The advantages of optical fiber communication can be brought into full play here, gradually replace cables and be widely used. It is also used for long-distance trunk communication. In the past, it mainly relied on cable, microwave and satellite communication. Now, optical fiber communication has been gradually used and a bit transmission method with global advantages has been formed; It is used for global communication network and public telecommunication network of various countries (such as national primary trunk line, provincial secondary trunk line and branch line below county level in China); It is also used for high-quality color TV transmission, industrial production site monitoring and dispatching, traffic monitoring, control and command, urban cable TV network, common antenna (CATV) system, optical fiber LAN and other applications, such as in aircraft, spacecraft, ships, underground mines, power departments, military and corrosive and radiation.
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 realize communication, the baseband signal must be processed by the electric terminal and sent to the optical fiber transmission system to complete the communication process.
It is suitable for optical fiber analog communication system, as well as optical fiber digital communication system and data communication system. In optical fiber analog communication system, electrical signal processing refers to the amplification and pre modulation of baseband signal, while electrical signal reverse processing is the reverse process of originator processing, that is, demodulation, amplification and other processing. In optical fiber digital communication system, electrical signal processing refers to amplifying, sampling and quantization of baseband signal,?