Geometrical optics of a twist-oriented nematic liquid crystal

We have systematically analyzed the spatial dynamics of the polarization state of light in smoothly inhomogeneous anisotropic media. As a medium of this kind, we have considered a nematic liquid crystal with twist orientation. A system of coupled equations has been solved with respect to the Cartesian components of the electric-field component using a rotating coordinate system. We have shown that, upon propagation of light in this medium, the state of the polarization experiences oscillations the spatial frequency of which depends on the thickness of the specimen. Our analysis also has shown that, at an appropriate choice of the thickness, this twist cell behaves as a broadband half-wave plate.