Guiding of optical fields in a liquid crystal cylindrical fiber

The propagation of optical fields in a cylindrical waveguide is studied. We consider that a quiescent nematic core is surrounded by an infinite homogeneous isotropic cladding. We propose an analytic although approximate description of the reorientation induced by the optical field, Then by making systematic approximations in powers of two well defined parameters of the system, we calculate the dielectric tensor of the core, the ray trajectories, the field distributions and the spatial electromagnetic energy distribution within the guide, These quantities are calculated for field frequencies such that the dielectric anisotropy of the nematic is always negative, We show that in this case there exists a wave guide effect that concentrates the ray trajectories and the electromagnetic energy around the central axis of the cylinder. We discuss the limitations of our model as well as its advantages over pure numerical descriptions.