Conical diffraction in one dimensional lattice formed by waveguide array results in the two quasi beams. Scattering of the electromagnetic wave of either of two beams on defect is investigated. The defect is represented by the waveguide fabricated from negative refractive index material. It is embedded into waveguide array that consists of waveguides with positive refractive index. The numerical simulation demonstrates the strong reflection of the electromagnetic wave from defect of this kind.
Maimistov, A. I., & Bykov, N. V. (2015). Conical Diffraction in One Dimensional Media Containing the Negative Index Defect. In Physics Procedia (Vol. 73, pp. 2–6). Elsevier B.V. https://doi.org/10.1016/j.phpro.2015.09.113