掺铒硫系玻璃光纤的中红外增益特性模拟研究

Theoretical Studies on Mid-Infrared Gain Characteristics of Erbium-Doped Chalcogenide Glass Fibers

实验制备了Er3+掺杂质量分数为1%的Ga5Ge20Sb10S65硫系玻璃,测试了其折射率、吸收光谱和荧光光谱,利用Judd-Ofelt和Futchbauer-Ladenburg理论计算了Er3+离子的自发辐射几率、吸收截面和受激发射截面等光谱参数。在综合考虑Er3+离子的交叉弛豫、能量上转换和激发态吸收效应的基础上,应用四能级粒子数速率-光功率传输方程模型,模拟计算了Er3+掺杂Ga5Ge20Sb10S65硫系玻璃光纤的中红外2.74μm波段的增益特性。结果显示,Er3+掺杂硫系玻璃光纤在2.74μm中红外波段具有较高的信号增益和较宽的增益谱,最大增益值和20dB增益带宽分别超过了40dB和200nm,表明其是可用于中红外2.74μm波段宽带放大的理想增益介质。

The Er3＋ doped（the mass fraction is 1%） Ga5Ge20Sb10S65 chalcogenide glasses are fabricated and the refractive index,absorption spectrum and emission spectra are measured.The spontaneous emission probability,absorption cross-section and emission cross-section are calculated using the theories of Judd-Ofelt and the Futchbauer-Ladenburg equation.Based on the rate equations and light propagation equations,the numerical simulations on mid-infrared gain characteristics for the Er3＋ doped Ga5Ge20Sb10S65 chalcogenide glass fiber are calculated.Effects of energy transfer between Er3＋ levels due to cross-relaxation,cooperative up-conversion and excited state absorption are considered in simulation.The results show that the Er3＋ doped Ga5Ge20Sb10S65 chalcogenide glass fiber has a bigger signal mid-infrared gain and wider mid-infrared gain spectrum,and its maximum signal gain and gain width at 20 dB exceeds 40 dB and 200 nm,respectively.The results indicate that the Er3＋ doped Ga5Ge20Sb10S65 chalcogenide glass is a better gain medium which can be applied to broadband amplifiers in mid-infrared.