Hybrid Broad-band EDFA/RFA

With the quick development of optical communication which is based on Dense Wavelength Division Multiplexing (DWDM), the working bandwidth of optical communication system is increasing continuously. So the effect of broad band optical fiber amplifyier in the modern optiwave system's development and application becomes more and more evident. The thesis studies the hybrid broad band optical fiber amplifier which is constructed by Erbium-doped-Fiber-Amplifiers (EDFA) and Raman- Fiber- Amplifiers (RFA).First, it retrospects the development of the optical fiber amplifier and introduces the basic principle of optical fiber amplifier, EDFA and RFA. Based on these theories it advances the design project of bandwidth amplifier which is constructed by EDFA and RFA. It establishes the theory model of EDFA and RFA. According to this it computes their gain. In order to make the whole gain of hybrid amplifier to some definite smoothness the thesis uses some optimized genetic algorithms to realize the gain flattening. It analyzes and designs the gain equalizer. According to the analysis of hybrid amplifier's noise, it computes the noise coefficient table of the whole system. Then it introduces four typical kinds of EDFA/RFA hybrid optical fiber amplifier.The design result shows that hybrid EDFA/RFA can realize the amplification of broad band and it has some specialty of high gain and low noise.