Whispering-gallery-mode (WGM) microresonators provide a high-performance platform for measuring single nanoparticles and viruses, as well as large molecules. However, there is still room for further improving their sensitivity and detection limit, towards their theoretical limit. Here, we present a new method that enhances the performance of WGM sensors based on the mode-splitting method. We show that scatterer-induced mode splitting is significantly enhanced in a rotating resonator. This enhancement originates from the different Sagnac frequency shifts that the clockwise and counterclockwise optical fields in the resonator experience due to the rotation of the resonator. Our approach, combining Sagnac shift and mode splitting, provides a new route for enhancing the coherent optical sensing of nanoparticles with single-particle resolution. In addition, our results shed light on the studies of, e.g., topological or optoacoustic effects with rotating devices.

中文翻译：

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利用旋转共振器进行纳米粒子感测

耳语画廊模式（WGM）微谐振器为测量单个纳米粒子和病毒以及大分子提供了高性能平台。但是，仍存在进一步提高其灵敏度和检测极限，使其接近理论极限的空间。在这里，我们提出了一种新的方法，它基于模式分割方法来增强WGM传感器的性能。我们表明，在旋转谐振器中，散射体引起的模式分裂显着增强。这种增强来自不同的Sagnac频移，谐振器中的顺时针和逆时针光场由于谐振器的旋转而经历了不同的Sagnac频移。我们的方法结合了Sagnac位移和模式分裂，为增强具有单粒子分辨率的纳米粒子的相干光学感测提供了一条新途径。