Two-Way Tuning of Whispering Gallery Mode Resonance of Dual-Frequency Nematic Liquid Crystal Microdroplets

Abstract

Nematic liquid crystals whose dielectric anisotropy changes sign above the crossover frequency are known as dual-frequency nematic liquid crystals (DFNLCs). Here, we report experimental studies on the whispering gallery mode (WGM) optical resonance in fluorescent dye-doped DFNLC microdroplets. The microdroplets are dispersed in a phospholipid-doped glycerol, forming a radial director structure. We investigate the effect of the amplitude and frequency of the applied electric field on the morphology and WGM resonance. We show that the WGM resonance can be tuned by changing the amplitude of the applied field at a fixed frequency and by varying the frequency at a fixed amplitude. Our experiments demonstrate that dual-frequency nematic liquid crystals provide new opportunities for tuning WGM resonance with frequency where the ability to tune by the amplitude of the electric field is limited.