High sensitivity refractive index and temperature sensor based on semiconductor metamaterial perfect absorber in the terahertz band

Abstract

We propose theoretically and numerically a highly sensitive refractive index and temperature sensor based on semiconductor metamaterials in the terahertz range. We demonstrate that the metamaterial sensor is a perfect absorber which absorption rate is 99.9% and because of including a square-shaped ring has a remarkable feature that is polarization independent of the incident light. The perfect absorber can be operated as a refractive index sensor with a sensitivity of 146600 nm/RIU. More importantly, the perfect absorber can be operated as a temperature sensor with a sensitivity of 7144 nm/K. The metamaterial structure has considerable potential in the chemical and biological applications because of having a high resolution.