Our calculation concerns two-dimensional photonic crystals (PCs) of hollow cylinders (in a dielectric matrix) that are infilled with a nematic liquid crystal (NLC). A static electric field, applied parallel to the cylinders, tunes the optical response of the PC. A crucial aspect is the calculation of the dielectric tensor of the NLC. Here we generalize a preliminary study [1], now considering three possible configurations: escaped radial, planar radial, and axial. Further, the anchoring of the molecules at the cylinder walls now has an arbitrary strength. Finally, we address the full problem of inhomogeniety and anisotropy of the NLC cylinders. A phase transition is found from the escaped radial to the axial configuration for sufficiently high field values, which depend on the cylinder radius. The Photonic Band (PB) structure reveals gaps for propagation in the [100] and [110] directions and also a PB gap in all directions (in the plane of periodicity) for modes that are approximately polarized parallel to the cylinders. Our results show that these gaps can be tuned by the applied field.
展开▼
