奇异点是非厄米系统参数空间中至少两个本征值和相应本征态同时简并的点,奇异点附近的异常光学现象,尤其是本征频率分裂对极小微扰的敏感特性,在超灵敏光学传感中有重要应用。本文主要结合近几年国内外关于奇异点的研究,介绍了奇异点及其在光学传感方面的相关理论,分析了奇异点传感和狄拉克点传感的不同;并着重总结奇异点传感在纳米颗粒检测、温度传感、折射率传感、光学陀螺仪和石墨烯生物化学传感等方面的最新研究进展。

Exceptional points are degeneracies where at least two eigenvalues and corresponding eigenstates coalesce simultaneously in the parameter space of non-Hermitian systems. The appealing optical phenomena that occur near exceptional points, especially the ultrasensitivity of frequency splitting to tiny perturbations, have important applications in ultrasensitive optical sensing. This review first introduces exceptional points and related theories in optical sensing. Subsequently, it analyzes the difference between exceptional-point sensing and diabolic-point sensing. Finally, having jointed latest researches at home and abroad, a variety of sensing applications based on exceptional points, including nanoparticle detection, temperature sensing, refractive index sensing, optical gyroscope, and graphene biochemical or chemical sensing, are reviewed.