Anisotropic polaritons in van der Waals materials
Weiliang Ma, Babar Shabbir, Qingdong Ou, Yemin Dong, Huanyang Chen, Peining Li, Xinliang Zhang, Yuerui Lu, Qiaoliang Bao
Polaritons in two‐dimensional (2D) materials continues to garner significant attention due to their favorable ability of field‐confinement and intriguing potential for low‐loss and ultrafast optical and photonic devices. The recent experimental observation of in‐plane anisotropic dispersion in natural van der Waals materials has revealed much richer physics as compared to isotropic plasmonic materials, which provides new insight to manipulate the polaritons and manufacture flat optical devices with unprecedented controls. Herein, we give an overview of the recent progress in in‐plane anisotropic polaritons launched and visualized in the near‐field range in 2D layered van der Waals materials. Furthermore, future prospects in this promising but emerging field are featured on the basis of its peculiar applications. This review article will stimulate the scientific community to explore other hyperbolic materials and structures in order to develop optical technologies with novel functionalities and further improve the understanding of the exotic photonic phenomena.