Refractive Index Sensor Based on a Metal–Insulator–Metal Waveguide Coupled with a Symmetric Structure
1
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, China
2
School of Science, Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology, Jiangnan University, Wuxi 214122, China
3
Aerospace Science and Technology Corporation, Beijing Institute of Space Long March Vehicle, Beijing 100036, China
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Sensors 2017, 17(12), 2879; https://doi.org/10.3390/s17122879
Received: 16 November 2017 / Revised: 4 December 2017 / Accepted: 6 December 2017 / Published: 11 December 2017
(This article belongs to the Section Physical Sensors)
Abstract
In this study, a new refractive index sensor based on a metal–insulator–metal waveguide coupled with a notched ring resonator and stub is designed. The finite element method is used to study the propagation characteristics of the sensor. According to the calculation results, the transmission spectrum exhibits a typical Fano resonance shape. The phenomenon of Fano resonance is caused by the coupling between the broadband spectrum and narrowband spectrum. In the design, the broadband spectrum signal is generated by the stub, while the narrowband spectrum signal is generated by the notched ring resonator. In addition, the structural parameters of the resonators and the structure filled with media of different refractive indices are varied to study the sensing properties. The maximum achieved sensitivity of the sensor reached 1071.4 nm/RIU. The results reveal potential applications of the coupled system in the field of sensors. View Full-TextKeywords:
surface plasmon polaritons; Fano resonance; finite element method; refractive index sensor
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Yan, S.; Zhang, M.; Zhao, X.; Zhang, Y.; Wang, J.; Jin, W. Refractive Index Sensor Based on a Metal–Insulator–Metal Waveguide Coupled with a Symmetric Structure. Sensors 2017, 17, 2879.
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