Linear and Nonlinear Optics of Confined Chiral Liquid Crystals at Weak Surface Anchoring

Abstract

The theoretical description of the optical properties of confined chiral liquid crystals (CLC) under action of a varying external agent for light propagating along the chiral axes is performed. The observed jumps and the hysteresis of the optical properties of confined CLC under action of a varying external agent are related to the surface anchoring. The detailed examination of the problem is carried out for the varying agent being the thickness of a planar layer in the case of a finite anchoring strength. Analytical expressions for the solution of the boundary-value problem for the absorbing (amplifying) CLC dependent on the layer thickness are presented. In particular, the equation for the lasing threshold for the edge lasing mode in a distributed feedback (DFB) lasing is obtained and analyzed. The connection of the optical characteristics of a CLC layer to the surface anchoring and, in particular, their discontinuity and hysteresis under variation of the layer thickness are demonstrated for a CLC layer of varying thickness and a wedge filled by CLC. It is shown that, in the case of a weak surface anchoring, the experimental measurements of the CLC layer optical characteristics under action of a varying external agent can be used to restore the actual surface anchoring potential.

Keywords:

• cano-granjean wedge
• chiral LC
• low threshold lasing
• surface anchoring

Acknowledgments

The work is supported by the RFBR grant 06-02-16287.