Design Of Raman And EDF Hybrid-amplifier And The Study On Gain-flattening

The society is in need of more and more information, which means that more transmission bandwidth can satisfy this need. EDFA is comparativly mature, characterized by low loss, high gain and high output power but relatively narrow bandwidth(1530-1565nm). While Distributed Fiber Raman Amplifier used as the on-line amplifier in the long-distance communication system can transmit and amplify simultaneously only to eliminate the accumulation of noise. In addition, it is characterized by wide band but relatively low gain. If put these two amplifiers together, the hybrid amplifier can not only own wide band and flat gain, but also can get relatively high output power and good noise feature. First the thesis makes a brief introduction about the history, the existing condition and the application prospect of fiber amplifiers. In addition, give a brief explanation and analysis on the concerned parameters and the principle of RFA and EDFA. Then design the driving and controlling circuits for the high output power of RFA pump module and the multipump intergrate,including temperature control, current control, protecting circuit, the circuit for sampling the operating parameters of the pump and also the displaying circuit, and the communication between itself and the PC. Software includes acquiring data, inspecting and process warning. Also make full use of the characteristics of the long period fiber grating including low loss, no relation with polarization and small volume, to make a study on the gain flattening of hybrid fiber amplifiers. At last study on the gain flattening experiment of Raman/EDF hybrid amplifier driven by the circuit mentioned above. To sum up, this paper is aimed at designing the high power driving and controlling circuit and multipump driving. In fact, the experiment shows that this kind of circuit can satisfy the needs with the driving current 1.2A. Then make the series of experiments on the flattening gain spectrum to the fiber amplifiers in C and L band, with the result of 1.2dB and 1.1dB respectively. All these will be references to the practical development and manufacture of the fiber amplifier.