Dependence of Core Size on Laser Action of Cholesteric Liquid Crystalline Microcapsules

Abstract

Cholesteric liquid crystalline (CLC) phases, which have helical superstructures, work as one-dimensional photonic crystals when the helical pitches are comparable to visible wavelengths. We have successfully fabricated water-in-oil-in-water double emulsions with CLC materials as the shell phase (CLC microcapsules). When a laser dye is dissolved in the core region, CLC microcapsules work as omnidirectional distributed Bragg reflection (DBR) resonators due to radial arrangement of their helical axes. The light-confinement effect at the center of the CLC microcapsule is different from that in the other region. We drained water in the core by using osmotic pressure to concentrate the dye at the center and studied the effect of the core size on the DBR laser action of the CLC microcapsules.