Field Enhancement in a Terahertz Plasmonic Structure and It's Sensing Applications

摘要

In this paper, we investigate the plasmonic response and electric field enhancement in a periodic array of InSb bowtie antenna with different gap distances and different carrier concentrations in the THz range, theoretically. We demonstrate the electric field intensity enhances by decreasing the gap distance and increment of InSb carrier concentration. We demonstrate the structure with the lowest gap distance and the highest carrier concentration, strongly enhances the electric field magnitude$(ert oldsymbol{E}ert ^{2}ert oldsymbol{E}_{0}ert ^{2}=79imes 10^{3})$. Also, our results show that by increasing the carrier concentration, the sensitivity and figure of merit (FOM) are improved. Finally, we propose a THz plasmonic sensor with higher sensitivity of 0.64 THz/RIU that can be utilized in important applications such as molecular detection, bio(chemical) and medical sensing in the THz range.