Figure 1.

Schematics of the signal detection system of whispering gallery mode (WGM) microresonator. (a) Sketch of an optical WGM microresonator coupled to a tapered fiber [24], where the input light was guided inside the tapered fiber from one end, and the resulting signal was detected at another end. (b) WGM biosensor platform, where input optics guided the light beam through the resonator, which was then detected at output optics [25]. (c) The detection system presented in this work was based on input light being guided inside the ball resonator, and the resulting back-reflected output signal was detected.