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The wave’s propagation through complex media plays a critical role in many areas of physical sciences 1. A good example of these media is photonic crystals. The term photonic crystal (PCs) was formed in 1987 after Yablonovitch 2 and John 3 had their first meeting in Princeton. PCs are a micro/Nanostructures which composed of spatial, periodic arrangement of dielectric materials with the high variation of refractive index. According to the geometry of structures, there are three types of PC structures are one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D). 1D PCs or called multilayer structures have a periodicity of refractive index in one direction but homogeneous in other two directions 4. 1D PCs have a large number of applications by embedded one or more defect layers through periodic layers 5,6,7.2D PCs are structures in which refractive index is varied in two directions while there is no variation in the third direction .3D- PCs are those in which periodicity of refractive index is in three directions. PCs take their importance from existence photonic band gaps in which frequency ranges of incident light are prohibited inside PCs. A large PBG is the cornerstone for various applications such as the omnidirectional high reflectors, high-Q microcavities, low threshold lasers, optical switches, and optical transistors 8, 9.
In the biological/chemical analysis, PCs play an essential role as label-free sensor since any changes in refractive index and /or thickness of the composing materials effect on the interaction of the PCs with analyte/fluid to be identified 10, 11. Many devices of label-free sensor based on 1D, 2D, and 3D PCs are designed by using different materials such as Silicon, TiO2 12, 13. For example, 1D silicon photonic crystal with an air defect is designed by M.Mohebbi 14 to oscillate at a single mode with a high-quality factor, allowing for refractive index sensing of gases with a high sensitivity. In recent days different types of PCs are used in biosensing field such as gene chips 15, blood glucose sensor 16, diabetes and blood disorders 17. It is worth mentioning these devices have many advantages are low cost, used low energy and provide measurements directly, in contrast, conventional methods which take a long time 18.
In this paper, we design a biosensor device based on 1D-defected binary PCs which is composed of ten periodic dielectric layers with hemoglobin solution as defect layer. It’s known that a unique features of PCs caused by the variations in index of refraction of constituent materials. As a result, we used Diamond and Silicon dioxide layers with high and low refractive index respectively and the defect layer of biological material sandwiched between them. The refractive index of the hemoglobin solution is affected by its concentration, so by changing hemoglobin concentration the propagation of EM waves through 1D-defected PCS is changed.

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