Electrically Controlled Lasing in Supercooled Liquid Crystal Blue Phase I Microdroplets

We have prepared the liquid crystal blue phase (BP) microdroplets emulsified in the glycerol environment and investigated their electro-optical properties upon the applied electric field. We showed that the lasing from the supercooled luminescent dye-doped BPI microdroplets can be controlled electrically. When the electric field intensity is increased, the lasing intensity is increased too along with the linewidth that decreases from 6 to 2.5 nm. Besides, the laser lines were shifted toward the shorter wavelength by 11 nm. All effects were achieved via electric field-stimulated structural and symmetrical modification of BPI microdroplets, resulting in their optical anisotropy and birefringence. Luminescent dye-doped liquid crystal blue phase-based microdroplets can find applications as electrically controlled microlaser sources for microphotonics and environmental sensing.