双包层光纤放大器小信号时放大的自发辐射特性研究

Amplified Spontaneous Emission Behavior under Small Signal Amplification in a Er^(3+)/Yb^(3+) Co-doped Double-clad Fiber Amplifier

基于速率方程,针对不同的泵浦方式,对双包层Er3+/Yb3+共掺光纤放大器小信号放大时放大的自发辐射(ASE)特性进行了全面研究。研究结果表明:反向泵浦时,ASE+输出功率大于ASE-输出功率,各波长分量对ASE+输出功率的贡献大于该波长分量对ASE-输出功率的贡献;增加纤芯数值孔径,无论正向泵浦还是反向泵浦,ASE输出功率都单调减小;当包层对芯径面积之比小于某一特定值时,对于反向泵浦,ASE+输出功率大于ASE-输出功率。这些特点显示了小信号放大时ASE与大信号放大时ASE所存在的差异。

Based on rate-equation, amplified spontaneous emission （ASE） behavior in the Er^3＋/Yb^3＋ co-doped double-clad fiber amplifiers under small signal amplification and different pump configuration is studied completely. This result shows that the ASE behavior under small signal amplification is different from that under large signal amplification. When backward pumping configuration is employed, ASE ＋ output power is larger than that of ASE- output power,and the contribution of each wavelength to ASE＋ output power is larger than that of the wavelength to ASE- as well. Whether forward or backward pumping configuration is employed,ASE output powers decrease gradually with the increasing of core NA. When the ratio of cladding to core area is less than a specific value, the output power of ASE＋ is larger than that of ASE- for backward pumping.