We describe a method that enables free-standing whispering-gallery-mode microresonators, and report spectral tuning of photonic molecules formed by coupled free and on-chip resonators with different geometries and materials. We study direct coupling via evanescent fields of free silica microtoroids and microspheres with on-chip polymer coated silica microtoroids. We demonstrate thermal tuning of resonance modes to achieve maximal spectral overlap, mode splitting induced by direct coupling, and the effects of distance between the resonators on the splitting spectra.
© 2012 Optical Society of America
Original Manuscript: May 24, 2012
Revised Manuscript: July 1, 2012
Manuscript Accepted: July 3, 2012
Published: August 10, 2012
Bo Peng, Şahin Kaya Özdemir, Jiangang Zhu, and Lan Yang, "Photonic molecules formed by coupled hybrid resonators," Opt. Lett. 37, 3435-3437 (2012)