Erkintalo Miro, Genty Goëry, Wetzel Benjamin, Dudley John M
Tampere University of Technology, Institute of Physics, Optics Laboratory, FIN-33101 Tampere, Finland.
Opt Express. 2010 Nov 22;18(24):25449-60. doi: 10.1364/OE.18.025449.
We consider the accuracy of modeling ultrashort pulse propagation and supercontinuum generation in optical fibers based on the assumption of a material Raman response that varies linearly with frequency. Numerical simulations in silica fiber using the linear Raman gain approximation are compared with simulations using the full Raman response, and differences in the spectral, temporal and stability characteristics are considered. A major finding is that for conditions typical of many experiments, although the input pulses may satisfy the criteria where the linear gain approximation is valid, the subsequent evolution and breakup of the input pulse can rapidly lead to a situation where the linear model leads to severe inaccuracies. Numerical artifacts within the linear model inducing unphysical pulse collapse are also identified.
我们基于材料拉曼响应随频率线性变化的假设，考虑了光纤中超短脉冲传播和超连续谱产生建模的准确性。将使用线性拉曼增益近似的石英光纤数值模拟与使用全拉曼响应的模拟进行了比较，并考虑了光谱、时间和稳定性特征方面的差异。一个主要发现是，对于许多实验的典型条件，尽管输入脉冲可能满足线性增益近似有效的标准，但输入脉冲的后续演化和分裂会迅速导致线性模型产生严重不准确的情况。还识别出了线性模型中导致非物理脉冲坍缩的数值伪像。
