Refractive index detection of liquid based on magneto-optical surface plasmon resonance

Abstract

We propose a refractive index sensor applied in liquid detection based on magneto-optical surface plasmon resonance. The device is made of a prism-coupling system, which consists of a prism and a CeYIG/Au/liquid waveguide. Systematic simulations using the finite element method and 4 × 4 transfer matrix methods are implemented to calculate the figure of merit (FOM) of sensitivity. Calculation results show that a FOM of 5.022/RIU for refractive index variation from 1.330 to 1.345 can be obtained when the incident wavelength is 980 nm. The proposed structure can achieve high angular sensitivity for the magnetic field of the proposed structure concentrated in the sensing medium. Meanwhile, our sensor, with gold as the bottom layer, is a better hydrophily for the molecular self-assembly technique compared with other conventional sensors, which makes it more practical in applications.