The coupling of defects in one-dimensional left-handed photonic crystal

摘要

The transmission of a one-dimensional left-handed photonic crystal consisting of alternating slabs of two materials with positive and negative refractive index respectively is investigated with the help of transfer matrix method (TTM). The properties of defect modes of the left-handed photonic crystal were disclosed. Both the number and the location of defect modes strongly depend on the property and composition of defects. The defect modes resulted from negative defect often appears in the zero average refractive index (ZARI) gap, while those resulted from positive defect usually appears in the Bragg gap. The defect modes, no matter in the Bragg gap or in the ZARI gap, exhibit degeneracy and split as the distance between the two defects decreases. Due to the coupling of the two defects, the split of defect mode does not appear when two different kinds of defect are introduced.