Observation of higher-order exceptional points in a non-local acoustic metagrating
Xinsheng Fang, Nikhil JRK Gerard, Zhiling Zhou, Hua Ding, Nengyin Wang, Bin Jia, Yuanchen Deng, Xu Wang, Yun Jing, Yong Li
Abstract
Abstract Higher-order exceptional points have attracted increased attention in recent years due to their enhanced sensitivity and distinct topological features. Here, we show that non-local acoustic metagratings enabling precise and simultaneous control over their multiple orders of diffraction can serve as a robust platform for investigating higher-order exceptional points in free space. The proposed metagratings, not only could advance the fundamental research of arbitrary order exceptional points, but could also empower unconventional free-space wave manipulation for applications related to sensing and extremely asymmetrical wave control.