Thin Film Sensing with Asymmetric Terahertz Metasurfaces

In this work, we demonstrate asymmetric terahertz metasurfaces for thin film sensing. The asymmetric SRR based metasurface design is observed to excite a sharp Fano-like dark mode resonance which is not seen in the corresponding symmetric SRR based design. The simulated transmission characteristics show a close match with the experimental results. Sensitivity and Figure of Merit have been calculated for both the sensor designs and it is observed that the Fano-identical dark mode resonance in the asymmetric SRR based metasurface is highly suitable for thin film sensing due to its high FoM value.