Wang Quansen, Liu Chun, Song Chao, Ding Hua, Wang Xu, Li Yong
Institute of Acoustics, Tongji University, Shanghai, China.
Nat Commun. 2025 Aug 28;16(1):8066. doi: 10.1038/s41467-025-63557-1.
Chiral vortex beams with tunable topological charges (TCs) hold promise for high-capacity and multi-channel information transmission. However, asymmetric vortex transport, a crucial feature for enhancing robustness and security, often disrupts channel independence by altering TCs, causing signal distortion. Here, we exploit the radial mode degree of freedom in chiral space to achieve extremely asymmetric transmission with high energy contrast, while preserving chirality and TCs. This is enabled by radial mode modulation, induced by one-way momentum from an invasive metamaterial, resulting in full vortex transmission in one direction and complete isolation in the opposite. We further realize high-contrast asymmetric image transport by encoding information into different TC channels. Notably, this approach sustains near noise-immune performance at signal-to-noise ratios as low as -25 dB, owing to TC preservation and the orthogonality of vortices with differing TCs. Our findings present a new strategy for chiral beam control and pave the way for secure, directional, and noise-resilient information transport in structured wave platforms.
具有可调拓扑电荷（TC）的手性涡旋光束有望实现高容量和多通道信息传输。然而，不对称涡旋传输作为增强鲁棒性和安全性的关键特性，常常通过改变拓扑电荷来破坏通道独立性，从而导致信号失真。在此，我们利用手性空间中的径向模式自由度，在保持手性和拓扑电荷的同时，实现具有高能量对比度的极端不对称传输。这是通过由侵入性超材料的单向动量引起的径向模式调制实现的，导致在一个方向上完全涡旋传输而在相反方向上完全隔离。我们通过将信息编码到不同的拓扑电荷通道中，进一步实现了高对比度的不对称图像传输。值得注意的是，由于拓扑电荷的保留以及不同拓扑电荷的涡旋的正交性，该方法在低至 -25 dB 的信噪比下仍能保持近乎抗噪声的性能。我们的研究结果提出了一种手性光束控制的新策略，并为结构化波平台中安全、定向和抗噪声的信息传输铺平了道路。
