State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China.
State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, 100083, Beijing, China.
Nano Lett. 2021 Feb 24;21(4):1566-1575. doi: 10.1021/acs.nanolett.0c04090. Epub 2020 Dec 23.
Optical microresonators have attracted intense interests in highly sensitive molecular detection and optical precision measurement in the past decades. In particular, the combination of a high quality factor with a small mode volume significantly enhances the nonlinear light-matter interaction in whispering-gallery mode (WGM) microresonators, which greatly boost nonlinear optical sensing applications. Nonlinear WGM microsensors not only allow for label-free detection of molecules with an ultrahigh sensitivity but also support new functionalities in sensing such as the specific spectral fingerprinting of molecules with frequency conversion involved. Here, we review the mechanisms, sensing modalities, and recent progresses of nonlinear optical sensors along with a brief outlook on the possible future research directions of this rapidly advancing field.
在过去的几十年中，光学微谐振器在高灵敏度分子检测和光学精密测量方面引起了极大的兴趣。特别是，高品质因数与小模式体积的结合极大地增强了 whispering-gallery 模式（WGM）微谐振器中的非线性光物质相互作用，从而极大地推动了非线性光学传感应用。非线性 WGM 微传感器不仅允许对分子进行超灵敏的无标记检测，而且还支持传感中的新功能，例如涉及频率转换的分子的特定光谱指纹识别。在这里，我们回顾了非线性光学传感器的机制、传感模式以及最新进展，并对这个快速发展的领域的未来可能的研究方向进行了简要的展望。
