Title: Guided modes in thin periodic honeycomb structures.
Photonic crystals are materials with a periodic structure that allows them to control the propagation of light. Due to the complexity of the structure (multiple reflections due to the periodicity of the material), destructive interference phenomena can appear at certain frequencies. More precisely, there are frequency intervals in which monochromatic light rays cannot propagate. Moreover, the introduction of linear perturbations in these media can generate guided modes propagating along the perturbations. In this talk, we study particular ‘honeycomb’ (hexagonal symmetry) periodic materials consisting of a mesh of thin tubes. We show some remarkable properties of this medium: presence of conical tips in the dispersion surfaces, creation of flat guided modes following the introduction of a linear zigzag defect. The presented work is the result of a collaboration with Sonia Fliss.