近日，美国南加州大学Khajavikhan, Mercedeh团队报道了通过光学热力学实现光的通用路由。该项研究成果发表在2025年9月25日出版的《自然—光子学》杂志上。

理解和开发复杂非线性系统的动力学是当今广泛的科学和技术努力的核心。在光学领域，非线性多模环境下的光演化是一个棘手的问题，因为它的混沌演化常常阻碍预测。最近，人们提出了一种光学热力学框架，该框架不仅可以系统地预测而且可以利用这些系统的复杂行为。

通过运用熵原理，研究组展示了一个反直觉的光学过程，在这个过程中，光被发射到一个精心设计的非线性阵列的任何输入端口，普遍通道进入一个紧密定位的基态，这是一个在线性保守安排中完全无法实现的响应。这种现象源于晶格结构与动力学和非线性哈密顿分量展开方式之间的相互作用，导致两种光学热过程：焦耳-汤姆逊类膨胀和模式热化。

在实验中，这种效应在适当配置的非线性时间合成网格晶格中得到了证明，其中光学温度接近于零，引导光在单个点上凝聚，而不管初始激发位置如何。研究组展示的效应为应用光学热力学原理实现新的光学功能开辟了新的途径，例如在高功率状态下的全光光束导向、多路复用和非线性光束整形，同时也提供了对多模非线性系统中光-物质相互作用显著物理的更好理解。

附：英文原文

Title: Universal routing of light via optical thermodynamics

Author: Dinani, Hediyeh M., Pyrialakos, Georgios G., Berman Bradley, Abraham M., Monika, Monika, Ren, Huizhong, Selim, Mahmoud A., Peschel, Ulf, Christodoulides, Demetrios N., Khajavikhan, Mercedeh

Issue&Volume: 2025-09-25

Abstract: Understanding and exploiting the dynamics of complex nonlinear systems is nowadays at the core of a broad range of scientific and technological endeavours. Within the optical domain, light evolution in a nonlinear multimode environment presents a formidable problem, as its chaotic evolution often hinders predictive insights. Recently, an optical thermodynamic framework has been put forward that, in a systematic manner, can not only predict but also harness the intricate behaviour of these systems. By deploying entropic principles, here we demonstrate a counter-intuitive optical process in which light, launched into any input port of a judiciously designed nonlinear array, universally channels into a tightly localized ground state, a response that is completely unattainable in linear conservative arrangements. This phenomenon arises from the interplay between lattice structure and the way the kinetic and nonlinear Hamiltonian components unfold, leading to two optical thermal processes: Joule–Thomson-like expansion followed by mode thermalization. Experimentally, this effect is demonstrated in properly configured nonlinear time-synthetic mesh lattices, where the optical temperature approaches near zero, causing light to condense at a single spot, regardless of the initial excitation position. The effect demonstrated here opens new avenues for applying the principles of optical thermodynamics in realizing new optical functionalities, such as all-optical beam-steering, multiplexing and nonlinear beam-shaping in high-power regimes, while also offering a greater understanding of the notable physics of light–matter interactions in multimode nonlinear systems.

DOI: 10.1038/s41566-025-01756-4

Source: https://www.nature.com/articles/s41566-025-01756-4