The Transmission Spectrum of Symmetrical Structured One-Dimensional Photonic Crystals of Positive and Negative Materials

The transmission spectrum of symmetrically structured one-dimensional photonic crystal (AB)m(BA)m consisting of positive and negative materials was studied with transfer matrix method theory. The result shows that a single narrow transmission peak constantly appears at the frequency of uneven ω/ω0, while a broad transmission peak appears at the frequency of even ω/ω0. When periodicity m or refractive index nA of Layer A increase, the narrow transmission peaks in the spectrum become sharper and the broad peaks become narrower; as refractive index nB of Layer B rises, all the peaks in the spectrum become broader; and when the thickness dA of Layer A medium thicken, the transmitting peaks move towards alto frequency,while with the thickening of dB of Layer B medium, these peaks move inversely towards low frequency. Furthermore, in these two circumstances, the transmitting peaks at right alto frequency move faster; however, peaks remain unchanged when both dA and dB concurrently thicken. All these optical transmission characteristics of symmetrically structured one-dimensional photonic crystals can offer guidance to designing adjustable super-narrow optical filters, broad band filters and optical switches.