Application of whispering-gallery-mode optical microcavities for detection of silver nanoparticles in an aqueous medium

Abstract

The results of an experimental investigation of a sensor intended for detection and measurement of concentration of nanoparticles in an aqueous medium, which is based on optical-dielectric whispering-gallery-mode microcavities, are presented. Variation of the frequency and Q-factor of the eigenmodes of the microcavity upon its interaction with silver nanoparticles is studied. It is demonstrated that this type of sensor can be used for measurement of infinitesimally low concentrations of nanoparticles.