Lasing and waveguiding in smectic A liquid crystal optical fibers

Abstract

© 2014 SPIE. We demonstrate a new sort of optical fibers, which are self-assembled from a smectic-A liquid crystal. When this liquid crystal is put in contact with water solution of surfactant CTAB, microfibers start spontaneously growing at the liquid crystal-water interface. The fibers are of very uniform diameter and can be several hundreds of micrometers long. They all have a line topological defect in the core of the fiber with a local optical axis pointing from the defect core towards the surface. The ends of the fiber are of perfect spherical shape. By doping the fibers with a fluorescent dye, we demonstrate guiding of light along the fiber. When the fiber is illuminated with pulsed light, which is absorbed by the dye, we observe Whispering Gallery Mode (WGM) lasing in a plane perpendicular to the fiber. The smectic-A fibers are soft and flexible and can be manipulated with laser tweezers demonstrating a promising approach for the realization of soft matter photonic circuits.