本文基于多横模运转的传输速率方程,建立了多芯光子晶体光纤放大器的数值模型.利用分步傅里叶方法,分析了掺杂浓度分布、耦合强度、抽运功率对于放大器各模式输出功率的影响.通过对多芯光子晶体光纤掺杂浓度的阶梯设计和纤芯间耦合强度的优化,实现了无需插入其他外加元件,利用光纤本身特性就可以实现选定同相位超模的方法,并且数值计算表明高抽运功率也能够提高放大器输出同相位超模的比例,进一步优化了多芯光子晶体光纤放大器输出脉冲的光束质量.
A model based on propagation-rate equations by considering the multi-transverse mode is constructed to describe the amplifer made from seven-core photonic crystal fbers.The output power of the seven eigenmodes in the amplifer infected by the dopant distribution,coupling coefcient and the pump power is discussed using the split-step Fourier algorithm.Mode selection can be realized by the design of dopant distribution and suitable coupling coefcient without the need of other devices.Mode selection may become more convenient due to this method.Moreover,high pump power can contribute to the improvement of the in-phase supermode.These results are helpful for improving the light quality of the amplifer.