Study Of EYDFA In The Application Of Optical Fiber Transmission System Of CATV System

The practical use of EDFA in 1989 , which created a revolution in long distancesoptical communication system, was an important milestone in the history of opticalfiber communication systems. Nowadays, EDFAs are widely used in all kinds ofoptical fiber communication systems. In optical fiber communication of CATV, EDFAsare commonly used as optical fiber amplifier. EDFAs have low noise figure, highoutput power and can amplify the optical signal directly, so the optical signaltransmission distance is prolonged. Since the advent of EYDFA , the selection ofoptical amplifiers in optical fiber communication system becomes more flexible. In thelong-distance optical fiber transmission systems of CATV, the power that generated byoptical transmitter is very low, so a couple of EDFAs are used to overlay all the opticalnodes in the system. Compared with EDFA, EYDFA has higher output power, and oneEYDFA can substitute 4 to 8 EDFAs, which makes the optical link and maintenacemore simple, and also cuts the costs of the system .In this paper, the application research of EDFA and EYDFA in CATV system hasbeen developed through the optical transmission system of CATV in Xinghua. Thechanges of the fiber network topology, system design and the assignment of the systemtargets have been studied when EYDFA were applied in the system. By comprehensivecomparison, a conclusion is made that the deterioration of system CNR which causedby one EYDFA is lower than EDFAs so the system performance is improved and oneEYDFA can substitute EDFAs in the system.