高浓度镱铒共掺磷酸盐光纤放大器增益特性

在忽略高能级的自发辐射和光纤损耗的情况下，利用速率方程和传输方程理论研究了高浓度Er³⁺/Yb³⁺共掺磷酸盐玻璃光纤放大器的增益特性，讨论了Er³⁺浓度、Yb³⁺浓度、抽运光功率、信号光功率、光纤长度对放大器增益的影响，并与单掺铒光纤放大器进行了比较.由于Yb³⁺的敏化作用降低了铒离子的团簇效应，减少了离子间相互作用，共掺光纤的增益和效率明显高于单掺光纤.数值计算表明，3.2cm长Er³⁺/Yb³⁺共掺光纤在980nm的20dBm(100mW)抽运功率下，1532nm处的增益可达10dB.关键词：镱铒共掺光纤放大器速率方程传输方程高浓度

Gain characteristics of high-concentration Er3+/Yb3+-codoped phosphate fiber amplifier

The gain characteristics of Er³⁺/Yb³⁺-codoped phosphate fiber amplifier pumped with light of 980nm wavelength are theoretically studied in this paper. With the help of rate equations and the propagation equation of Er³⁺/Yb³⁺-codoped phosphate fiber, we analyzed the effects of concentration of erbium and ytterbium ions, pump power, signal power and fiber length on the gain characteristics of the co-doped fiber amplifier. Comparison with singly erbium-doped fiber amplifier was also made. It is shown that the sensitization of Yb³⁺ decreases the clustering effect of erbium ions in the fiber and the gain and pump efficiency of Er³⁺/Yb³⁺ co-doped fiber are apparently higher than that of singly erbium-doped fiber. Numerical results also demonstrate that considerable signal gain of 10dB can be achieved in a 3.2cm-long fiber amplifier with 20dBm(100mW) pumping power at 980 nm.