Comment on properties of one-dimensional photonic crystals containing negative refraction materials

In this paper, by using the transfer matrix theory and the dispersion relation principle, via math tool processing numerical value simulation get the energy band, the limited field and the dispersion characteristic of one-dimensional photonic crystals with negative-index materials, we find there are two photonic band gap, the lower forbidden band which is called zero-(n) over bar gap remains nearly invariant under a various incident angle, while the higher one which is called Bragg gap changes ceaselessly with the increasing incident angle. Through introducing the defect we found that the defect mode inside the zero-(n) over bar gap remains invariant with the scaling of non-defect part. Conversely, the defect mode inside the Bragg gap shifts greatly in frequency with scaling. The studying of the dispersion relation shows that the width of the zero-(n) over bar gap enlarges, but the middle of each gap hardly changes, on the contrary the middle of a Bragg gap will shift noticeably while the width of the gap will change a little when the ratio of the thicknesses of the two types of layers varies and that the zero-(n) over bar gap that distinguishes itself from a Bragg gap in that it is invariant with scaling. The emphasis of this paper lies in analyzing the characteristic of this type of photonic crystals.