Infrared metamaterial refractive-index-based sensor

We have introduced an infrared refractive-index-based sensor operating at the infrared frequency region. In designing the sensor, we have used a metamaterial structure with unit cells composed of two metallic layers, the first involving two metallic bars and slabs, and the second containing a uniform metallic sheet. With a mechanism analogous to the theoretical blackbody absorber, the structure behaves as a resonant perfect absorber. Its resonance frequency strongly depends on the refractive index of the surrounding medium, a characteristic that is used for designing the sensor. In general, the sensitivity of the sensor is calculated to be 2720 nm/RIU, equivalent to 940 THz/RIU, and the figure of merit is calculated to be 81.93. We have also studied potential application of the sensor for glucose solution concentration detection, which is important in medical and food industries. (C) 2020 Optical Society of America