A MEMBRANCE For Gain Control EDFA

Recently, high information capacity of WDM technology, widely contributed significantly to the rapid development of optical communication technology. However, due to the traditional quality of erbium-doped silica fiber amplifier with lower concentrations of rare earth doped, narrow gain bandwidth and low gain flatness, greatly restricted the current high-speed large-capacity optical information transmission and integration requirements. Another WDM system transient fluctuations in the signal light by the accumulation of multi-stage EDFA, the line will cause obstruction or generate error even burn communications device, so that the automatic gain control of wide bandwidth high-gain erbium-doped fiber amplifier research has significance.In this paper, two aspects of the gain controlled EDFA research, starting materials, the study of a new erbium-doped gain fiber: Er-Yb co-doped fluorophosphate glass fiber materials. Study the various components of the preparation process of the fluoride and phosphate glass fiber material properties, were prepared by thermal stability (Δ T=141℃) high transmittance without crystallization fluorophosphate fiber material. By spectra analysis, preparation of Yb3+/Er3+co-doped fluorophosphate fiber material has a high absorption cross section (2.075pm2), high emission cross section (1.11pm2), long fluorescence lifetime (6.07ms) and high-gain coefficient (1.649mspm2), is an excellent high gain, wide bandwidth optical amplifier gain material.From the EDFA’s overall design, all-optical ring cavity automatic gain control method, the use of the feedback loop of the spontaneous emission of photons and the signal light on the competitive level inversion of rare earth, the shift to automatic gain control purposes. Use software Gain fiber Er3+/Yb3+co-doped fluorophosphate fiber all-optical ring cavity automatic gain control fiber amplifier simulation and analysis, in Er3+/Yb3+co-doped fluorophosphate fiber length of6m obtained when the The best gain effect, and the entire bandwidth of the1525nm-1560nm range to obtain a high and flat gain flatness is less than2.5dB, noise figure less than3.5dB, the signal light to-5dBm, pump power of200mw obtained27.1dBm when the signal gain, pump light use efficiency of81.1%. Obviously, Er3+/Yb3+co-doped fluorophosphate fiber than the average of the erbium-doped silica fiber with shorter fibers, higher the gain, gain bandwidth wider, higher gain flatness, a new type of EDFA gain fiber is better choice. Design of the ring optical automatic gain control erbium-doped fiber amplifier in the signal light occurs+/-5dBm of input power, the output gain changes only+/-0.8dBm, that the design of all-optical gain controlled EDFA in the ring cavity played a good effect.