Transmission characteristics of one-dimensional photonic crystal with dielectric defect layer in near-infrared band

In this paper, a one-dimensional photonic crystal with dielectric defect layer was studied in near-infrared band. For photonic crystal with only one defect layer, the effects of refractive index and thickness of defect layer, photonic crystal structure and incident angle on defect mode were discussed in detail. A photonic crystal structure with two defect layers was proposed, which had two defect modes in the forbidden band. The position of the two defect modes could be regulated by adjusting the number of photon periods and the thickness of the defect layer. Based on this structure, a twochannel narrow band filter was designed. The calculation results showed that the transmittance at the two defect modes of 1310 nm and 1550 nm reached 92.16% and 95.44%, respectively, while the full width at half maximum was only 5.5 nm and 9.7 nm. The simulation of the electric field distribution in the defect mode further proved the correctness of the design results. The research results had important value in the field of optical communication.