Omnidirectional resonance modes in photonic crystal heterostructures containing single-negative materials

Multiple omnidirectional resonance modes are generated in the periodic arrangement of photonic crystal (PC) heterostructures with two sub-PCs consisting of single-negative (permittivity- or permeability-negative) materials. The key to designing such heterostructures is that only one of the sub-PCs possesses the zero-φeff gap. It is found that the resonance transmission modes inside the zero-φeff gap of these heterostructures are insensitive to incident angle. Moreover, as the periods of the heterostructure increases, the resonance transmission modes will split and be located symmetrical on both sides of the midfrequency of the zero-φeff gap.