Research Paper: Design of Simple Plasmonic Sensors based on Graphene Circles in THZ Region

Abstract

The design of optical sensors in the THz region for application in various fields of biological and medical sciences has significantly expanded in the last two decades. In this paper, we proposed an optical sensor using two dimensional and periodic structure of graphene rings on the dielectric substrate. The surface plasmon resonance mechanism was employed to design the refractive index sensor. First, by changing the geometric parameters of the structure, the optimal parameters for the sensor performance have been extracted. Then, the sensor's sensitivity has been checked regarding the change in the refractive index of the surrounding environment. The sensitivity of the proposed simple structure is 11.2 μm/RIU and is larger than previous works. Also, increasing the refractive index of the measured medium diminished the quality of sensor operation. The proposed sensor can be used to detect environmental air pollution by proper calibration. The Lumerical software which is based on the finite difference time domain method is used to this end.

Keywords

• plasmonic sensor
• 2d materials
• fdtd
• sensitivity
• figure of merit