Exceptional points (EPs), at which two or more eigenvalues and eigenstates of a resonant system coalesce, are associated with non-Hermitian Hamiltonians with gain and/or loss elements. Dynamic encircling of EPs has received significant interest in recent years, as it has been shown to lead to highly nontrivial phenomena, such as chiral transmission in which the final state of the system depends on the encircling handedness. Previously, chiral transmission for a pair of eigenmodes has been realized by establishing a closed dynamical trajectory in parity-time- (PT-) or anti-PT-symmetric systems. Although chiral transmission of symmetry-broken modes, more accessible in practical photonic integrated circuits, has been realized by establishing a closed trajectory encircling EPs in anti-PT-symmetric systems, the demonstrated transmission efficiency is very low due to path-dependent losses. Here, we demonstrate chiral dynamics in a coupled waveguide system that does not require a closed trajectory. Specifically, we explore an open trajectory linking two infinite points having the same asymptotic eigenmodes (not modes in PT- and anti-PT-symmetric systems), demonstrating that this platform enables high-efficiency chiral transmission, with each eigenmode localized in a single waveguide. This concept is experimentally implemented in a coupled silicon waveguide system at telecommunication wavelengths. Our work provides a new evolution strategy for chiral dynamics with superior performance, laying the foundation for the development of practical chiral-transmission devices.

异常点 (EP) 是谐振系统的两个或多个特征值和特征态合并的点，与具有增益和/或损失元素的非厄米哈密顿量相关。近年来，EP 的动态环绕引起了人们的极大兴趣，因为它已被证明会导致非常重要的现象，例如手性传递，其中系统的最终状态取决于环绕的旋手性。此前，一对本征模的手性传递是通过在宇称时间（PT）或反PT对称系统中建立闭合动力学轨迹来实现的。尽管在实际光子集成电路中更容易实现对称破缺模式的手性传输，已经通过在反PT对称系统中建立环绕EP的闭合轨迹来实现，但由于路径相关损耗，所证明的传输效率非常低。在这里，我们演示了不需要闭合轨迹的耦合波导系统中的手性动力学。具体来说，我们探索了连接具有相同渐近本征模（不是 PT 和反 PT 对称系统中的模式）的两个无限点的开放轨迹，证明该平台能够实现高效手性传输，每个本征模都位于单个波导中。这一概念已在电信波长的耦合硅波导系统中通过实验实现。我们的工作为具有优越性能的手性动力学提供了一种新的演化策略，为实用手性传输器件的开发奠定了基础。