Measuring nematic liquid crystal anchoring energy using whispering gallery modes.

Whispering gallery modes (WGMs) around the liquid crystal droplets are sensitive to the director orientation at the interface. An electric field was applied for changing the director orientation of a nematic liquid crystal droplet surrounded by polydimethylsiloxane (PDMS), which induced vertical director orientation at the interface. WGMs were shifted by varying the electric field intensity, and WGM shift-dependent director response was calculated. From this calculation we obtained the extrapolation length of 0.35 ± 0.02 μm. These results indicate that WGM sensitivity can be used for obtaining the surface properties of liquid crystals.