Zero-averaged refractive-index gaps extension by using photonic heterostructures containing negative-index materials.

We show theoretically that the frequency range of the zero-averaged refractive-index gap can be substantially extended in a photonic heterostructure containing negative-index materials. This photonic heterostructure consists of different one-dimensional (1D) photonic crystals. The constituent 1D photonic crystals have to be properly chosen in such a way that their zero-averaged refractive-index gap of the adjacent photonic crystals overlap each other. [ABSTRACT FROM AUTHOR]