宽带Er-Tm共掺石英光纤放大自发辐射特性分析

Theoretical Analysis of Broadband Amplified Spontaneous Emission Behavior in Er-Tm Co-doped Silica Fiber

探索了新型Er-Tm共掺石英基质超荧光光纤光源的特性,在粒子数方程和功率传输方程的基础上对其放大自发辐射(ASE)特性进行了理论分析。在单向泵浦中,分析了泵浦功率和信号功率随光纤长度的变化特性,描述了在不同光纤长度、离子浓度及泵浦功率下信号谱的变化趋势;在双向泵浦中,讨论了泵浦功率和信号功率随光纤长度的变化特性以及信号谱相对于光纤长度和泵浦功率的稳定性。结果显示,利用Er-Tm共掺石英基质光纤可以获得稳定的100nm放大自发辐射带宽,大约是传统掺铒光纤超荧光光源带宽的两倍,但输出功率比后者低3个量级以上。

Incoherent broadband optical sources have been used in various applications, such as fiber-optic gyroscopes, dense wavelength division multiplexing （DWDM） ,and broadband amplification. In order to analyze the characteristics of a novel Er-Tm co-doped silica fiber as superfluorescent sources, the amplified spontaneous emission （ASE） behavior is studied theoretically based on the rate and propagation equations. When the fiber is single-end pumped,the changes of ptrmp power and total signal power along the fiber are analyzed,and the characteristics of signal spectrum as functions of fiber length, ion concentrations and pump power are discussed. When the fiber is dualport pumped ,the pump and signal power as functions of the fiber length are also discussed,and the stability of signal spectrum in different fiber length and pump power is presented. These results show that the Er-Tm co-doped silica fiber could provide more than 100nm effective ASE bandwidth,which is twice larger than the conventional singly erbium-doped fiber ASE source,but the output power is three level magnitude lower than the latter ASE source.