arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.19482physics.optics
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具有动态多模增益的时空锁频中的双稳态

Bistability in spatiotemporal mode-locking with dynamic multimode gain

Zhijin Xiong, Yuankai Guo, Wei Lin, Hao Xiu, Yuncong Ma, Xuewen Chen, Zhaoheng Liang, Lin Ling, Tao Liu, Xiaoming Wei, Zhongmin Yang

AI总结:

本文在广义多模非线性薛定谔方程框架下研究STML多模光纤激光器的动态多模增益模型,揭示了由多模增益效应和时空可饱和吸收主导的两种工作状态,实验首次验证了后者的3D耗散孤子双稳态及多模增益整形机制。

摘要:

存在于时空锁模(STML)多模光纤激光器中的三维(3D)耗散孤子已被证明是产生高能量飞秒脉冲的一种极具前景的理论形式,但遗憾的是,它们表现出尚未被完全理解的多样时空动力学。对STML多模光纤激光器进行完整建模可以为时空动力学的底层物理提供新见解,从而更好地操控高质量高能飞秒脉冲的产生,然而这一目标在很大程度上仍未实现。为此,本文在广义多模非线性薛定谔方程框架下,通过探讨多模速率方程(MMRE),对STML多模光纤激光器的动态多模增益模型进行了理论研究。利用该动态多模增益模型,重新审视了吸引子解剖理论,以理解决定3D耗散孤子模态成分的主导效应。具体而言,通过改变多模增益光纤(MMGF)的数值孔径,观察到了对应于不同类型增益吸引子的不同增益动力学。结果,识别出两种截然不同的STML工作状态,它们分别由多模增益效应和时空可饱和吸收主导。特别是在后一种状态下,3D耗散孤子呈现出双稳态,即存在具有两种不同线偏振(LP)模态成分的分叉解。为了验证这些理论发现,实验结果表明STML的状态可以在不同LP模态之间切换,并证实了双稳态的存在。特别是,据我们所知,由多模增益效应主导的3D孤子整形机制首次得到了验证。

英文摘要:

Three-dimensional (3D) dissipative soliton existed in spatiotemporal mode-locked (STML) multimode fiber laser has been demonstrated to be a promising formalism for generating high-energy femtosecond pulses, which unfortunately exhibit diverse spatiotemporal dynamics that have not been fully understood. Completely modeling the STML multimode fiber lasers can shed new light on the underlying physics of the spatiotemporal dynamics and thus better manipulate the generation of high-quality energic femtosecond pulses, which however is still largely unmet. To this end, here we theoretically investigate a dynamic multimode gain model of the STML multimode fiber laser by exploring the multimode rate equation (MMRE) in the framework of generalized multimode nonlinear Schrödinger equation. Using this dynamic multimode gain model, the attractor dissection theory is revisited to understand the dominant effects that determine the modal composition of 3D dissipative soliton. Specifically, by varying the numerical aperture of the multimode gain fiber (MMGF), different gain dynamics that correspond to distinct types of gain attractors are observed. As a result, two distinguishing STML operation regimes, respectively governed by the multimode gain effect and spatiotemporal saturable absorption, are identified. In the latter regime, especially, 3D dissipative solitons present bistability that there exist bifurcated solutions with two different linearly polarized (LP) mode compositions. To verify the theoretical findings, the experimental implementation shows that the state of STML can be switched between different LP modes, and confirms the presence of bistability. Particularly, the 3D-soliton shaping mechanism that is governed by the multimode gain effect is testified for the first time, to the best of our knowledge.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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