Complete tunneling through three-layered periodic structures with metamaterial in far-infrared region

We study the tunneling modes in three different periodic structures with epsilon-negative (ENG) and mu-negative (MNG) materials defined by Lorentz type model in far-infrared region, including (ENG–MNG)N, (ENG–MNG–ENG)N and (MNG–ENG–MNG)N. Transfer matrix method is used to analyze these periodic structures, and the influences of the incident angle, the period number, thickness of every layer and their ratio on the transmittance spectra are discussed based on simulation results. Simulation results show the periodic structure with unit of (MNG–ENG–MNG) is a better choice for stable band-pass tunneling modes.