Full Tunability of Whispering-Gallery-Modes in Resonators Made from Liquid-Crystal Elastomers

Whispering-Gallery-Mode (WGM) resonators hold huge potential for various future application due to their high quality factors and low mode volumes. Hereby, their field of possible applications is further widened if the spectral position of the WGMs can be precisely and reversibly tuned. To this goal, we propose a WGM resonator entirely made from Liquid-Crystal Elastomer. These polymers undergo an anisotropic mechanical actuation under various external stimuli due to a reversible change of their molecular order. Exploiting this mechanism, the spectral position of a WGM is tuned by precisely controlling the resonator’s radius using temperature as an external stimulus. The WGM’s full tunability is demonstrated by means of fiber-based transmission spectroscopy.