DIRECTOR DISTRIBUTION IN A CLC HYBRID CELL WITH A SMALL HELICOIDAL PITCH

Abstract

Laser light emission in dye-doped chiral liquid crystals (CLCs) has been experimentally demonstrated for the homeotropic–planar (hybrid) orientation. A numerical simulation of this structure showed that the helicoid (helix) pitch period in CLC in the hybrid cell and the director distribution depend significantly on the anchoring energy at the homeotropic sample boundary. The anchoring energy plays the role of a factor facilitating the CLC helix unwinding. The lower anchoring energy, the smaller the pitch is and the closer to the natural CLC pitch it is. In this case, the length of the “screw"-type structure near the homeotropic cell boundary decreases. Thus, as the anchoring energy at the hybrid-cell homeotropic boundary decreases, the director distribution in the cell approaches the distribution in the planar (Grandjean) cell. This is confirmed by the laser light emission in the same spectral range as in the planar cell.