Complete band gaps in one-dimensional photonic crystals with negative refraction arising from strong chirality

In this paper, we propose the idea of using chiral negatively refractive media to realize three-dimensional (3D) complete band gaps in the one-dimensional (1D) photonic crystals with a two-layer unit cell. We explain why at least a three-layer unit cell is necessary for realizing the 3D complete band gaps in 1D achiral photonic crystals, and show how we can reduce the number of layers of the unit cell to two if chirality is introduced. Although the media with strong chirality supply negative refraction only for one of the two eigenwaves, the complete band gaps could be still obtained with an even simpler lattice structure compared to the achiral counterpart.