Scatterer induced mode splitting in poly(dimethylsiloxane) coated microresonators

We investigate scatterer induced mode splitting in a composite microtoroidal resonator (Q ~ 10^6) fabricated by coating a silica microtoroid (Q ~ 10^7) with a thin poly(dimethylsiloxane) layer. We show that the two split modes in both coated and uncoated silica microtoroids respond in the same way to the changes in the environmental temperature. This provides a self-referencing scheme which is robust to temperature perturbations. Together with the versatile functionalities of polymer materials, mode splitting in polymer and polymer coated microresonators offers an attractive sensing platform that is robust to thermal noise.Comment: 9 pages, 3 figures, 15 reference

Observation and characterization of mode splitting in microsphere resonators in aquatic environment

Whispering gallery mode (WGM) optical resonators utilizing resonance shift (RS) and mode splitting (MS) techniques have emerged as highly sensitive platforms for label-free detection of nano-scale objects. RS method has been demonstrated in various resonators in air and liquid. MS in microsphere resonators has not been achieved in aqueous environment up to date, despite its demonstration in microtoroid resonators. Here, we demonstrate scatterer-induced MS of WGMs in microsphere resonators in water. We determine the size range of particles that induces MS in a microsphere in water as a function of resonator mode volume and quality factor. The results are confirmed by the experimental observations.Comment: 4 Pages, 5 Figures, 13 Reference