Fabrication of ultraviolet-curable adhesive bottle-like microresonators by wetting and photocuring.

This work presents a remarkably simple method for the fabrication of ultraviolet (UV)-curable adhesive bottle-like microresonators (BLMRs). The main fabrication process involves two steps: (1) creating liquid bottle-like microcavities along the taper waist of an optical fiber taper under interfacial tension and (2) curing the liquids into solids by UV light irradiation. The shape of the BLMRs can be fitted with a truncated harmonic-oscillator profile. Whispering gallery mode resonances of the bottle-like microcavity were excited via a tapered fiber at different positions along its axis. A cleaner spectrum with identifiable and traceable features over a broad wavelength range at the center excitation position and the estimated Q factors close to 10⁵ around 1.55 μm are observed. The shifts of resonance frequency by the input light power change demonstrate the potential applications of thermo-optic sensing and frequency tuning.