Whispering gallery modes in self-assembled bottle microresonators coupled to planar waveguide

Polymer micro-bottle resonators are fabricated by means of a simple self-assembling process. High optical quality SU-8 negative resist is chosen as bottle material. SU-8 is dispensed onto a fiber stem and is kept in rotation during the UV photo-polymerization. Micro-bottles with different geometrical sizes have been obtained by changing the SU-8 dispensed volume, with a repeatability of about 2%. Planar waveguides is chosen as interrogation system for our SU-8 self-assembled micro-bottle resonators. The highest quality factor Q associated to the resonance peak in the transmission spectrum is about 3.8 × 104