Document Type : Research
Authors
1 Department of Optical Fiber, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran
2 Department of laser, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran
3 Department of Semiconductor, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran
Abstract
A B S T R A C T
Graphene is a two-dimensional material that has attracted much attention due to its unique properties for the excitation of surface plasmon waves. Surface plasmons in graphene can be generated at frequencies in the mid-infrared to terahertz range, which is not possible using conventional plasmonic materials such as noble metals. For these reasons, surface plasmon waves on graphene have potential applications in new nanosensors. In this paper, we investigate the propagation of surface plasmon waves in single-layer graphene. In the designed structure, the graphene layer is placed on a photonic crystal and a defect in this photonic crystal is used to build the sensor. Surface plasmon waves in this structure can propagate on graphene and their intensity and quality factor in the disorder region are much higher than those of surface plasmon waves generated in a structure with a periodic substrate. Therefore, in this paper, the significant enhancement of the field related to surface plasmon waves in the defect region is used to design a nanosensor. The results show that small changes in the refractive index due to changes in the properties of the sensing region in the presence of biological material with steps of 0.015 cause a 5 nm shift in the peak wavelength of the structure. Therefore, changes in the range of a few nanometers can be detected using this nanosensor. In this paper, this structure has been used as a biological sensor for the detection of Escherichia coli bacteria.
Keywords
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