Complex Light Dynamics复杂光场动力学

Light can inhabit many different physical worlds. In one setting, it behaves like a particle moving through an effective landscape; in another, it reveals its wave nature through interference, radiation, and localization. By shaping the geometry, motion, and interactions of an optical system, we can make these different descriptions tangible—and use them to realize phenomena that would otherwise seem inaccessible.光能够呈现出许多看似截然不同的物理图景。有时，它像粒子一样在人工构造的势能场中运动；有时，它又以波的形式展现干涉、辐射与局域化。通过调控光学系统的结构、运动和相互作用，我们可以把这些抽象的物理图景转化为真实可见的实验现象，并进一步探索那些隐藏在自然之下的状态。

From a particle-like perspective, a beam can be stabilized at the top of an effective potential rather than at its minimum. The mechanism is analogous to the stability of Trojan asteroids near the L4 and L5 Lagrange points, located sixty degrees ahead of and behind a planet in its orbit. In a rotating optical landscape, an effective Coriolis force can hold the beam near such a point, allowing it to circulate around an otherwise unstable equilibrium. The optical field then behaves as though it were a small celestial body trapped within a synthetic Sun–Jupiter system: localized not by an ordinary potential well, but by motion, geometry, and the rotating frame itself.从粒子的角度看，光束甚至可以被稳定在势能的“山顶”，而不是通常意义上的势阱底部。这与太阳系中的特洛伊小行星十分相似：在太阳和木星共同形成的旋转引力场中，在科里奥利力的帮助下，小行星能够停留在行星轨道前后约六十度的 L4 和 L5 拉格朗日点附近。同样的，在旋转的光学势场中，等效科里奥利力也可以将不稳定平衡点变稳定，使光束围绕其持续运动。此时，光就像运行在一个人工“太阳—木星”系统中的天体；维持它局域的并不是普通的势阱，而是旋转参考系、几何结构和动力学效应的共同作用。

The same light can also enter a very different regime governed by its wave nature. A mode embedded within a continuum of radiating states would ordinarily be expected to leak away. Yet carefully structured interference can cause all of its outgoing radiation channels to cancel, leaving the field perfectly confined. This is a bound state in the continuum: a localized optical mode existing where localization should seemingly be impossible. The trapping mechanism is not a material barrier or a conventional cavity, but the destructive interference of the wave with itself.从波的角度看，同一束光又会展现完全不同的可能。一个处在连续辐射谱中的光学模式，按常理应当不断向外泄漏，却可能因为各个辐射通道之间发生精确的相消干涉而被牢牢束缚。这就是连续谱中的束缚态：一个本应辐射消散的光学模式，却能够长期保持局域。困住它的并非材料屏障或传统光学腔，而是光波自身的干涉。

These examples are two entrances into a much broader landscape. Light provides a platform for exploring non-Hermitian dynamics, topological protection, time reflection, spatiotemporal media, nonequilibrium transport, and optical thermodynamics. Many of these phenomena challenge familiar distinctions—between localization and radiation, stability and instability, equilibrium and nonequilibrium, or space and time — and turn ideas once regarded as mathematical curiosities into controllable experiments.这些现象只是通往更广阔物理世界的几个入口。非厄米光子学、光的拓扑保护、时间反射与时空介质、非平衡输运，以及光热力学，都可以借助光学系统被构造、调控和观测。它们不断重新定义我们熟悉的边界：局域与辐射、稳定与不稳定、平衡与非平衡，甚至空间与时间之间，都可能出现超出直觉的新关系。

Our interest lies not only in observing such unusual effects, but in understanding the principles that connect them and learning how to engineer them. When light is placed in synthetic landscapes, driven far from equilibrium, or coupled across many degrees of freedom, familiar rules can give way to new forms of motion, organization, and control. For those drawn to physics at the boundaries between waves and particles, order and disorder, and conventional and synthetic dimensions, much remains unexplored.我们不仅希望观察这些反常而迷人的现象，更希望理解它们背后的共同规律，并探索如何主动创造和利用它们。当光被置于人工势场之中、被驱动至远离平衡的状态，或在大量自由度之间发生耦合时，熟悉的物理规则可能让位于全新的运动、组织与控制方式。在波与粒子、秩序与无序、真实空间与人工维度的交界处，仍然有许多问题等待我们去发现。