Near-Field Radiation Interaction With Molecules in Optical Microcavity

Evanescent radiation-molecule interactions in an optical microcavity device are characterized. The device is operated at whispering-gallery modes, and consists of a microcavity and a micro-waveguide coupled by a sub-micrometer air-gap. Under optical resonance, a strong evanescent field arises along the periphery of the circular resonating microcavity. This radiation will certainly interact with molecules inside the field and may induce changes in the resonant field. Such induced changes are investigated and its potential in the detection of single molecules is discussed.