近日，新加坡南洋理工大学的Marco Battiato及其研究小组取得一项新进展，经过不懈努力，他们成功发现了自陡峭效应和拉曼自频移存在下的高阶怪波分裂。相关研究成果已于2023年5月10日在国际知名学术期刊《物理评论A》上发表。

该研究利用广义非线性薛定谔方程研究了自陡峭和拉曼诱导自频移对高阶怪波解的影响。研究人员观察到每种效应都会分解高阶怪波，将其还原为其基本组成部分，类似于高阶孤子的分裂。应用局部反散射技术，研究人员证实，在自频移效应下，怪波的出现显著影响了周围的波背景，触发了孤子、呼吸子和新的怪波。

此外，他们还展示了孤子转化之前分裂步骤的中间过程，这些过程只能在存在弱扰动的情况下被观察到。这些观察揭示了在光纤中调制不稳定性诱导的超连续谱产生过程中，产生大量孤子的机制。他们证实，在三阶色散、自陡峭和拉曼诱导自频移的联合作用下，高阶怪波的分解元素成为基本孤子，产生了不对称的频谱剖面，生成了红移和蓝移的频率分量。

此外，研究人员还展示了孤子转化之前的分裂步骤中间过程，这些过程只能在存在微弱扰动的情况下才能被观察到。这些观察结果揭示了在光纤中通过调制不稳定性诱导的超连续谱生成过程中，形成大量孤子的机制。

附：英文原文

Title: Higher-order rogue-wave fission in the presence of self-steepening and Raman self-frequency shift

Author: Amdad Chowdury, Wonkeun Chang, Marco Battiato

Issue&Volume: 2023/05/10

Abstract: Using the generalized nonlinear Schrdinger equation, we investigate how the effect of self-steepening and Raman-induced self-frequency shift impact higher-order rogue-wave solutions. We observe that each effect breaks apart the higher-order rogue wave, reducing it to its constituent fundamental parts, in a similar manner to how a higher-order soliton undergoes fission. Applying a local inverse-scattering technique, we show that under the effect of self-frequency shift, the emergence of a rogue wave significantly influences the surrounding wave background, triggering solitons, breathers, and new rogue waves. We demonstrate that under the combined effect of third-order dispersion, self-steepening, and Raman-induced self-frequency shift, the disintegrated elements of higher-order rogue waves become fundamental solitons, creating an asymmetrical spectral profile that generates both red- and blue-shifted frequency components. We also show the intermediary processes of the fission steps prior to soliton transformation which can only be observed in the presence of weak perturbations. These observations reveal the mechanisms that create a large number of solitons in the process of modulation instability-induced supercontinuum generation from a continuous-wave background in optical fibers.

DOI: 10.1103/PhysRevA.107.053507

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.053507