A High-Sensitivity Refractive-Index Sensor Based on Plasmonic Waveguides Asymmetrically Coupled with a Nanodisk Resonator
XIAO Li-Ping, WANG Fa-Qiang**, LIANG Rui-Sheng, ZOU Shi-Wei, HU Miao
Laboratory of Nanophotonic Functional Materials and Devices, and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006
Abstract：A high-sensitivity plasmonic refractive-index sensor based on the asymmetrical coupling of two metal-insulator-metal waveguides with a nanodisk resonator is proposed and simulated in the finite-difference time domain. Both analytic and simulated results show that the resonance wavelengths of the sensor have an approximate linear relationship with the refractive index of the materials which are filled into the slit waveguides and the disk-shaped resonator. The working mechanism of this sensor is exactly due to the linear relationship, based on which the refractive index of the materials unknown can be obtained from the detection of the resonance wavelength. The measurement sensitivity can reach as high as 6.45×10?7, which is nearly five times higher than the results reported in the recent literature [Opt. Commun. 300 (2013) 265]. With an optimum design, the sensing value can be further improved, and it can be widely applied into the biological sensing. The sensor working for temperature sensing is also analyzed.
. [J]. 中国物理快报, 2015, 32(07): 70701-070701.
XIAO Li-Ping, WANG Fa-Qiang, LIANG Rui-Sheng, ZOU Shi-Wei, HU Miao. A High-Sensitivity Refractive-Index Sensor Based on Plasmonic Waveguides Asymmetrically Coupled with a Nanodisk Resonator. Chin. Phys. Lett., 2015, 32(07): 70701-070701.
2015, Vol. 32 
