A new multiple scattering method application: Simulating an infinite 2D photonic crystal by analyzing, sorting and suppressing the border effects

We present in this paper a study of border effects due to the limitation in width of a finite-size two-dimensional (2D) photonic crystal. Using the multiple scattering method (based on a rigorous electromagnetic theory of the diffraction of light) the band gap of a finite piece of photonic crystal is no longer parabolic. Peaks and oscillations appear in the band gap resulting from multi-reflexion inside the structure which couple with the Fabry-Perot cavity constituted by the lateral edges. We numerically demonstrate that reducing the lateral symmetry eliminates border effects (peaks and oscillations). This result is independent of the geometry of the 2D photonic crystal.