Foreman Matthew R, Swaim Jon D, Vollmer Frank
Max Planck Institute for the Science of Light, Laboratory of Nanophotonics and Biosensing, Günther-Scharowsky-Straße 1, 91058 Erlangen, Germany.
Adv Opt Photonics. 2015 Jun 30;7(2):168-240. doi: 10.1364/AOP.7.000168.
We present a comprehensive overview of sensor technology exploiting optical whispering gallery mode (WGM) resonances. After a short introduction we begin by detailing the fundamental principles and theory of WGMs in optical microcavities and the transduction mechanisms frequently employed for sensing purposes. Key recent theoretical contributions to the modeling and analysis of WGM systems are highlighted. Subsequently we review the state of the art of WGM sensors by outlining efforts made to date to improve current detection limits. Proposals in this vein are numerous and range, for example, from plasmonic enhancements and active cavities to hybrid optomechanical sensors, which are already working in the shot noise limited regime. In parallel to furthering WGM sensitivity, efforts to improve the time resolution are beginning to emerge. We therefore summarize the techniques being pursued in this vein. Ultimately WGM sensors aim for real-world applications, such as measurements of force and temperature, or alternatively gas and biosensing. Each such application is thus reviewed in turn, and important achievements are discussed. Finally, we adopt a more forward-looking perspective and discuss the outlook of WGM sensors within both a physical and biological context and consider how they may yet push the detection envelope further.
我们对利用光学回音壁模式（WGM）共振的传感器技术进行了全面概述。在简短介绍之后，我们首先详细阐述光学微腔中WGM的基本原理和理论以及常用于传感目的的转换机制。重点介绍了近期对WGM系统建模和分析的关键理论贡献。随后，我们通过概述迄今为止为提高当前检测限所做的努力来回顾WGM传感器的技术现状。这方面的提议众多，例如从等离子体增强和有源腔到已经在散粒噪声受限 regime 中工作的混合光机械传感器。在提高WGM灵敏度的同时，提高时间分辨率的努力也开始出现。因此，我们总结了这方面正在采用的技术。最终，WGM传感器旨在实现实际应用，如力和温度测量，或者气体和生物传感。因此，依次对每个此类应用进行了回顾，并讨论了重要成果。最后，我们采用更具前瞻性的视角，在物理和生物学背景下讨论WGM传感器的前景，并考虑它们如何进一步拓展检测范围。
