Properties of defect modes in one-dimensional photonic crystals containing a defect layer with a negative refractive index

Abstract

The band structures of one-dimensional photonic crystals containing a defect layer with a negative refractive index are studied, showing that the defect modes possess three types of dispersion: positive, zero, and negative types. The zero and negative dispersion phenomena may be useful in the design of large incident angle filters and narrow frequency and sharp angular filters, respectively. The dispersion multiplicity of the defect modes can be understood by an approximate formula. Moreover, the splitting of one defect mode into multiple defect modes is observed in the band gap when the parameters of the defect layer vary. This phase transition phenomenon may be useful in the design of multiple channeled filters or filters with a rectangular profile. The condition for the critical point of the phase transition is also analyzed.