基于四波混频的光纤非线性系数测量方法

为解决四波混频法测量光纤非线性系数未考虑泵浦消耗而导致结果不准确的问题,提出了一种在简并四波混频情况下测量非线性系数的方法.根据光纤中简并的四波混频理论,推导出了考虑泵浦消耗和光纤损耗的椭圆方程.通过设定数值计算所需的各个参量并利用简单的数学方法分析了计入泵浦消耗、光纤损耗的必要性,得到被测光纤的非线性系数,与Optisystem的仿真结果一致.研究表明,这种改进的测量方法不但适用于小信号情形下的四波混频过程,还可以应用于出现参量饱和现象的场合,为进一步设计光纤2R再生器件提供了重要依据.

Measurement Method of Fiber Nonlinear Coefficient Based on Four Wave Mixing

Pump depletion was not taken into account in the four wave mixing based measurement technique for fiber nonlinear coefficient, which made the results inaccurate. To solve this, the elliptical equation with pump depletion and fiber loss was derived based on the theory of degenerate four wave mixing. The nonlinear coefficient of the tested fiber could be obtained by setting the parameters in numerical calculation and utilizing simple mathematical method. The necessity of considering pump depletion and fiber loss was analyzed. The numerical results were consistent with the Optisystem simulation data. The improved method proposed in the can be applied to the small signal case, but also to the process of parametric saturation. This technique provided an important parameter for further designing the fiber based 2R regenerators.