This paper firstly investigates the solution of similariton chirp in a dispersion-decreasing fiber (DDF) and a nonlinearity increasing fiber (NIF) with different tapered profile. Based on the symmetry reduction technology and discrete variable method, a generalized analytical solution of the chirp for arbitrary tapered fiber is obtained and proved to be coincident with the numerical solution by simulation. The broadening factor is further studied to analyze the generation and compression characteristic of similaritons. We find out that the similaritons generated by DDF are more conducive to generate high-quality ultra-short output pulse than that generated by NIF with the same tapered profile. Finally, the optimum output ultrashort pulse with a maximum output power 382.31 W and a FWHM of 92.9 fs, and that with a maximum output power 319.63 W and a FWHM of 99.5 fs are achieved by compressing similaritons generated in hyperbolic tapered DDF and NIF respectively.

中文翻译：

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不同锥度 DDF 和 NIF 中相似啁啾的广义解析解研究

本文首先研究了色散降低光纤（DDF）和非线性增加光纤（NIF）中具有不同锥形轮廓的相似啁啾的解。基于对称约简技术和离散变量法，得到了任意锥形光纤线性调频的广义解析解，并通过仿真证明与数值解是一致的。进一步研究了展宽因子以分析相似性的产生和压缩特性。我们发现，与 NIF 产生的相同锥形轮廓相比，DDF 产生的相似性更有利于产生高质量的超短输出脉冲。最后，最佳输出超短脉冲最大输出功率为 382.31 W，FWHM 为 92.9 fs，最大输出功率为 319。