Simultaneous Sensing of Refractive Index and Temperature Using a Symmetry-breaking Silicon Metasurface with Multiple Fano Peaks

In this paper, an asymmetric all-dielectric metasurface is used to measure the temperature and refractive index (RI) simultaneously. We use FDTD Solutions to obtain reflection spectrum, and use the two Fano peaks to realize two parameter sensing. The Fano resonance of narrow line width increases the figure of merit (FoM, ratio of sensitivity to full width at half maximum) by two orders of magnitude compared to previous proposed dual parameter sensors. Simulation reveals the sensor possessing RI sensitivities of 444.52 nm/RIU and 100.06 nm/RIU, FoMs of 1778.08 and 227.41, temperature sensitivities of 34.9 pm/°C and 83.8 pm/°C. The device has the advantages of simple structure, easy to manufacture, small volume and low loss. It has a good prospect in the application of biological and chemical sensing, especially in the measurement of substance concentration.