Bound States in the Continuum Enabled THz Dielectric Metasurface for High Sensitivity Refractive-Index Sensing

In this work we present a highly sensitive all-dielectric terahertz (THz) metasurface sensor consisting of an array of hollow cuboids made of silicon on top of a quartz substrate. The proposed design exploits the phenomenon of bound states in the continuum (BIC) to achieve a Q-factor of 10260 which corresponds to a sensitivity of 18.8 GHz/ RIU. This sensor is to be integrated in a continuous wave (CW) spectroscopy setup for the detection of chemical and biological substances based on refractive index sensing. The performance of the sensor offers a promising approach towards label-free, cost-effective and room temperature operable sensing solutions.