Investigation Of Photonic Crystals Filter

Along with the rapid development of informationization in modern society, the problem of the frequency band resources and electromagnetic environment of the traditional electronic communication was becoming more and more serious, which had been unable to meet the demand of modern communication. The scientists have shown great interest in photonic crystals. With the advantages of high integrated degree, anti-interference and its like, the photonic crystal devices not only solved the bottleneck faced by electronic communication, but also opened up a new optical communication field. In this paper, a novel two-dimensional four-channel photonic crystal filter was studied. The photonic crystal theory and basic properties, photonic crystal devices and performance parameters were analyzed in detail.First, in this paper, the development history of photonic crystal filter, and the domestic and foreign research status were summarized. In addition, the concept of photonic crystals, basic characteristics and application areas, the basic principle and the fabrication technology of photonic crystal devices were described in detail, which provides a solid foundation for the analysis and research in the paper.Second, the numerical analysis method of photonic crystal was studied, including Plane Wave Expansion Method (PWE), Finite Difference Time Domain Method (FDTD) and Transfer Matrix Method (TMM). Then the factors that influence the photonic band gap were analyzed in view of the two-dimensional defect photonic crystal, and the result showed that photonic crystal lattice arrangement, the radius of defect dielectric rods and refractive rate will significantly impact the band gap of defect photonic crystal. The point defect, line defect and ring defect are respectively embedded into the complete photonic crystal, and then the relationship of micro-cavity resonance curve and radius of defect dielectric rod, transmission spectrum of waveguide and its transmission characteristics, the resonance curve characteristics of ring-cavity were analysed.Finally, the two-dimensional photonic crystal filters were studied. Based on the analysis of photonic crystal micro-cavity and ring-cavity coupled frequency-selective characteristics, the two-dimensional photonic crystal filter with a four channel not only improves the coupling efficiency, but also realizes the narrowband filter by optimizing the layout and the parameters of the device. In addition, the structure that composed by a ring-cavity and two micro-cavities was chose, which makes full use of multiple modes of the ring-cavity, and significantly reduces the physical dimensions of the device.