Refractive Index Sensor Based on a Metal-Insulator-Metal Bus Waveguide Coupled with a U-Shaped Ring Resonator

Xiaoyu Zhang; Shubin Yan; Jilai Liu; Yifeng Ren; Yi Zhang; Lifang Shen

doi:10.3390/mi13050750

Refractive Index Sensor Based on a Metal-Insulator-Metal Bus Waveguide Coupled with a U-Shaped Ring Resonator

Micromachines (Basel). 2022 May 9;13(5):750. doi: 10.3390/mi13050750.

Authors

Xiaoyu Zhang^{1

2

3}, Shubin Yan^{1

2}, Jilai Liu¹, Yifeng Ren³, Yi Zhang^{1

2}, Lifang Shen^{1

2}

Affiliations

¹ School of Electrical Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China.
² Joint Laboratory of Intelligent Equipment and System for Water Conservancy and Hydropower Safety Monitoring of Zhejiang Province and Belarus, Hangzhou 310018, China.
³ School of Electrical and Control Engineering, North University of China, Taiyuan 030051, China.

Abstract

In this study, a novel refractive index sensor structure was designed consisting of a metal-insulator-metal (MIM) waveguide with two rectangular baffles and a U-Shaped Ring Resonator (USRR). The finite element method was used to theoretically investigate the sensor's transmission characteristics. The simulation results show that Fano resonance is a sharp asymmetric resonance generated by the interaction between the discrete narrow-band mode and the successive wide-band mode. Next, the formation of broadband and narrowband is further studied, and finally the key factors affecting the performance of the sensor are obtained. The best sensitivity of this refractive-index sensor is 2020 nm/RIU and the figure of merit (FOM) is 53.16. The presented sensor has the potential to be useful in nanophotonic sensing applications.

Keywords: Fano resonance; SPPs; U-shaped ring resonator; metal-insulator-metal; sensor.

Abstract

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