Transmission Properties of One-Dimensional Photonic Crystals Containing Anisotropic Metamaterials

The transmission properties of one-dimensional photonic crystals (1DPCs) containing anisotropic metamaterials are theoretically studied. It is shown that the 1DPCs can possess a similar zero average index (zero-(n) over bar) gaps, the edges of zero-(n) over bar gap are weakly dependent on the incident angles, scale length and the polarization of the electromagnetic wave. When an impurity is introduced, a defect mode appears inside the zero-(n) over bar gap with a very weak dependence on incident angles and scaling. It is found that in such photonic crystals, a transmitted Gaussian pulse with its carrier frequency lying in the lower gap edge, in the defect mode and in the bandgap, can experience a positive or negative group delay and hence a subluminal, ultraslow or superluminal propagation with small distortions. These properties of the photonic crystals have potential applications in the transfer of information.