铋基掺铒光纤放大器宽带放大特性的理论研究

研制了铋酸盐基质掺铒玻璃43Bi2O3-30B2O3-27SiO2,测试分析了玻璃中Er3+离子的光谱性质。结合获得的Er3+离子光谱参数,建立了一个以该铋基掺铒玻璃作为放大器增益介质时Er3+离子跃迁的三能级理论模型,研究了铋基掺铒玻璃光纤放大器(Bi-EDFA)的信号放大特性。研究显示,单波长输入情形下,Bi-EDFA具有大于40dB的信号增益和75nm的3dB波长带宽。同时,相比于硅基掺铒光纤放大器(Si-EDFA),Bi-EDFA具有优异的多波长信号宽带放大和低噪声特性,低噪声系数(~5.5dB)可维持至1610nm波长之外。结果表明,铋基掺铒玻璃光纤放大器是一种单位长度增益极高和宽带放大能力的小型化掺铒光纤放大器,适合于WDM系统的集成化需求。

Broadband amplifying characteristics of a bismuth-based erbium-doped fiber amplifier

Bismuth-based erbium-doped glass with compositions of 43Bi2O3-30B2O3-27SiO2 are prepared,and the spectroscopic properties such as the intensity parameter,spontaneous emission probability,absorption and emission cross-section of Er3+ ions are calculated and analyzed according to the Judd-Ofelt and McCumber theory,respectively.The signal amplifying characteristics of bismuth-based erbium-doped fiber amplifier(Bi-EDFA) are investigated theoretically based on a three-level model of Er3+ ions under bi-directionally pumped at 1480nm.The numerical simulations show that Bi-EDFA has a signal gain over 40dB and a 3-dB bandwidth of over 75nm when single-wavelength signal is inputted.In addition,Bi-EDFA has a perfect multi-wavelength signal broadband amplification and low noise figure(NF) compared with that of silica-based EDFA,and its low NF(～5.5dB) can sustain beyond 1610nm.The results indicate that Bi-EDFA is a new type of erbium-doped amplifier suitable for WDM system application with a high signal gain per unit length and amplifying bandwidth.