Enhanced coupling of subterahertz radiation with semiconductor periodic slot arrays

In this work, a theoretical study of the coupling of TM polarized subterahertz ( THz) radiation with periodic semiconductor rectangular slot arrays was conducted, using InSb as an example. Simulation results showed that the structure with 4-12 mu m thickness provides over a 20-30-fold increase in the electric field at slot edges in a nanosize region (similar to 500 nm). The enhancement of the THz electromagnetic field extends across the slots and reaches peak values at the edges due to discontinuity effects. Because of the strong local electromagnetic field enhancement, the structure can potentially be used for the development of novel biophotonic sensors, leading to improved detection sensitivity.