Scheibinger Ramona, Lüpken Niklas M, Chemnitz Mario, Schaarschmidt Kay, Kobelke Jens, Fallnich Carsten, Schmidt Markus A
Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745, Jena, Germany.
Institute of Applied Physics, University of Münster, Corrensstraße 2, 48149, Münster, Germany.
Sci Rep. 2021 Mar 5;11(1):5270. doi: 10.1038/s41598-021-84397-1.
Supercontinuum generation enabled a series of key technologies such as frequency comb sources, ultrashort pulse sources in the ultraviolet or the mid-infrared, as well as broadband light sources for spectroscopic methods in biophotonics. Recent advances utilizing higher-order modes have shown the potential to boost both bandwidth and modal output distribution of supercontinuum sources. However, the strive towards a breakthrough technology is hampered by the limited control over the intra- and intermodal nonlinear processes in the highly multi-modal silica fibers commonly used. Here, we investigate the ultrafast nonlinear dynamics of soliton-based supercontinuum generation and the associated mode coupling within the first three lowest-order modes of accurately dispersion-engineered liquid-core fibers. By measuring the energy-spectral evolutions and the spatial distributions of the various generated spectral features polarization-resolved, soliton fission and dispersive wave formation are identified as the origins of the nonlinear broadening. Measured results are confirmed by nonlinear simulations taking advantage of the accurate modeling capabilities of the ideal step-index geometry of our liquid-core platform. While operating in the telecommunications domain, our study allows further advances in nonlinear switching in emerging higher-order mode fiber networks as well as novel insights into the sophisticated nonlinear dynamics and broadband light generation in pre-selected polarization states.
超连续谱产生促成了一系列关键技术，如频率梳源、紫外或中红外波段的超短脉冲源，以及用于生物光子学光谱方法的宽带光源。利用高阶模的最新进展已显示出提升超连续谱源带宽和模式输出分布的潜力。然而，朝着突破性技术的努力受到常用的高多模石英光纤内模内和模间非线性过程控制有限的阻碍。在此，我们研究基于孤子的超连续谱产生的超快非线性动力学以及精确色散工程化液芯光纤前三个最低阶模内的相关模式耦合。通过测量能量谱演化以及偏振分辨的各种生成光谱特征的空间分布，孤子分裂和色散波形成被确定为非线性展宽的起源。利用我们液芯平台理想阶跃折射率几何结构的精确建模能力进行的非线性模拟证实了测量结果。虽然在电信领域运行，但我们的研究有助于新兴高阶模光纤网络中非线性开关的进一步发展，并能对预选偏振态下复杂的非线性动力学和宽带光产生有新的见解。
