Packaged optofluidic microbubble resonators for optical sensing.

A microbubble resonator (MBR) coupled with a fiber taper is packaged with low-index polymer. The cladding polymer serves as a protective matrix for the coupling system to avoid environmental disturbance. The packaged structure is portable and provides good performance to maintain high Q factors for a long working period. The hollow structure of the MBR makes the packaged system useful for practical chemical and biomedical sensing applications. To evaluate the performance of the packaged MBRs-based sensor, we carry out bulk refractive index and surface-sensing measurements with achieved sensitivities of 18.8 nm/RIU and 31.29 pm/nm, respectively.