Photonic band gap from a stack of single-negative materials

We investigate the transmission gap of the multilayer structure consisting of alternate permittivity-negative material layer and permeability-negative material layer. It is found that for both normal and oblique incidences, there exists a transmission gap which is invariant with a change of scale length. In view of the fact that the layers are electrically thin, the effective permittivity epsilon(eff) and permeability mu(eff) are introduced to study the transmission property of electromagnetic waves. Numerical results show that the transmission gap can be well explained by the total reflection (epsilon(eff)mu(eff) - epsilon(air)mu(air)sin(2) theta < 0, where theta is the incident angle). To one's interest, the edges of the gap can be accurately determined by epsilon(eff)mu(eff) - epsilon(air)mu(air)sin(2) theta = 0. In addition, we show that zero effective phase shift gap (zero-phi(eff) gap) and zero volume averaged refractive index gap (zero-n gap) can also be understood in a similar way. (c) 2005 Elsevier B.V. All rights reserved.