Refractive Index Sensing Based on Terahertz Spoof Surface Plasmon Polariton Structure

Surface plasmon resonance sensing technology has many advantages, such as high sensitivity, no interference to samples and real-time monitoring. It has been widely used in biomedical detection, food safety testing and environmental protection etc. How to increase the measurement sensitivity is a key technology in these applications. In this paper, a stepped surface plasmon resonance sensing structure is proposed, which is easy to be machined. The influence of its structure parameters on the sensing sensitivity is simulated and analyzed. The results show that the sensitivity can be increased to 2.44THz/RIU by optimizing the structure parameters when the refractive index of the liquid to be measured is between 1.33 and 1.36.