Flow-Enhanced Performance of Optical Microcavity Biosensors

Whispering gallery mode optical resonators have become useful tools for label-free detection in recent years. While various geometries and methods of implementation have been studied, mass transport and flow around the optical microcavities has received relatively little attention. Here we report methods to optimize the interaction between the whispering gallery mode of the sensor and the species adsorbing to the surface by controlling flow around the resonator in order to improve the dynamic range. We model the flow conditions using COMSOL Multiphysics and compare these data with experimental results for a variety of resonator geometries.