Direct observations of thermalization to a Rayleigh–Jeans distribution in multimode optical fibres
Direct observations of thermalization to a Rayleigh–Jeans distribution in multimode optical fibres
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DOI：
10.1038/s41567-022-01579-y
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发表时间：
2022-04
期刊：
影响因子：
19.6
通讯作者：
H. Pourbeyram;P. Sidorenko;Fan O. Wu;N. Bender;Logan G. Wright;D. Christodoulides;F. Wise
中科院分区：
文献类型：
--
作者：
H. Pourbeyram;P. Sidorenko;Fan O. Wu;N. Bender;Logan G. Wright;D. Christodoulides;F. Wise
非线性多模光学系统支持许多有趣的效果，这在单模设置中是不可能的。虽然非线性可以提供一个丰富的环境，其中数千种模式之间的混沌功率交换可以导致新的行为，但理解和利用这些过程对我们有利是具有挑战性的。多年来，统计模型已经发展到宏观上描述这些复杂系统的响应。这些理论形式主义的基石之一是预测光子-光子介导的热化过程，导致模式职业的瑞利-金斯分布。在这里，我们报告使用模式分辨测量技术，直接观察热化的瑞利-金斯功率分布在多模光纤。我们的实验表明，底层系统的哈密顿量在传播过程中保持不变，而功率均分发生之间的退化组的模式，完全符合理论预测。我们的研究结果可能为新一代高功率光源铺平道路，其亮度和模态内容可以使用热力学和统计力学原理进行控制。
Nonlinear multimode optical systems support a host of intriguing effects that are impossible in single-mode settings. Although nonlinearity can provide a rich environment where the chaotic power exchange among thousands of modes can lead to novel behaviours, understanding and harnessing these processes to our advantage is challenging. Over the years, statistical models have been developed to macroscopically describe the response of these complex systems. One of the cornerstones of these theoretical formalisms is the prediction of a photon–photon-mediated thermalization process that leads to a Rayleigh–Jeans distribution of mode occupations. Here we report the use of mode-resolved measurement techniques to directly observe the thermalization to a Rayleigh–Jeans power distribution in a multimode optical fibre. We experimentally demonstrate that the underlying system Hamiltonian remains invariant during propagation, whereas power equipartition takes place among degenerate groups of modes—all in full accordance with theoretical predictions. Our results may pave the way towards a new generation of high-power optical sources whose brightness and modal content can be controlled using principles from thermodynamics and statistical mechanics.